The Direct Rambus DRAM (Direc t RDRAM) is a general purpose high-performance memory device suitable for
use in a broad range of applications including computer memory, graphics, video, and any other application where
high bandwidth and low latency are required.
The µPD488448 is 128M-bit Direct Rambus DRAM (RDRAM), organized as 8M words by 16 bits.
The use of Rambus Signaling Level (RSL) technology permits 600 MHz to 800 MHz transfer rates while using
conventional system and board design technologies. Direct RDRAM devices are capable of sustained data transfers
at 1.25 ns per two bytes (10 ns per sixteen bytes).
The architecture of the Direct RDRAMs allows the highest sustained bandwidth for multiple, simultaneous randomly
addressed memory transactions. The separate control and data buses with independent row and column control
yield over 95% bus efficiency. The Direct RDRAM’s thirty-two banks support up to four simultaneous transactions.
System oriented features for mobile, graphics and large memory systems include power management, byte
masking.
The µPD488448 is offered in a CSP horizontal package suitable for desktop as well as low-profile add-in card and
mobile applications. Direct RDRAMs operate from a 2.5 volt supply.
Features
Highest sustained bandwidth per DRAM device
•
- 1.6 GB/s sustained data transfer rate
- Separate control and data buses for maximized efficiency
- Separate row and column control buses for easy scheduling and highest performance
- 32 banks: four transactions can take place simultaneously at full bandwidth data rates
Low latency features
•
- Write buffer to reduce read latency
- 3 precharge mechanisms for controller flexibility
- Interleaved transactions
Advanced power management:
•
- Multiple low power states allows flexibility in power consumption versus time to transition to active state
- Power-down self-refresh
Overdrive current mode
•
Organization: 1 Kbyte pages and 32 banks, x 16
•
Uses Rambus Signaling Level (RSL) for up to 800 MHz operation
Some signals can be applied because this pin is not connected to the inside of the chip.
Note
DD
V
DD
GNDGNDV
DD
V
DD
GND
12
10
9
8
5
4
3
1
4
Data Sheet M14837EJ3V0DS00
µµµµ
Pin Description
SignalInput / OutputType#pinsDescription
Note1
SIO0, SIO1Input / Output
CMDInput
SCKInput
V
DD
V
DDa
V
CMOS
GND13Ground reference for RDRAM core and int erface.
GND
a
DQA7..DQA0Input / Output
CFMInput
CFMNInput
V
REF
CTMNInput
CTMInput
RQ7..RQ5 or
Input
ROW2..ROW0
RQ4..RQ0 or
Input
COL4..COL0
DQB7..DQB0Input / Output
NC2These pins aren’t connected to inside of the chip.
Total pin count per package62
CMOS
CMOS
CMOS
RSL
RSL
RSL
RSL
RSL
RSL
RSL
RSL
2Serial input/output. Pins for reading from and writing t o t he control registers using
a serial access protoc ol . Also used for power management.
Note1
1Command input. Pins used i n conjunction with SIO0 and SIO1 for reading from
and writing to the control regis ters. Also used for power managem ent.
Note1
1Serial clock input. Clock source used for reading from and writing to the control
registers.
10Supply voltage for t he RDRA M core and interface logic.
1Supply voltage for the RDRA M anal og circuitry.
2Supply voltage for CMOS i nput /output pins.
1Ground reference for RDRAM analog circ ui try.
Note2
8Data byte A. Eight pi ns whi ch carry a byte of read or write dat a between the
Channel and the RDRAM.
Note2
1Clock from master. I nterface clock used f or receiving RSL signals from the
Channel. Positive polarity.
Note2
1Clock from master. I nterface clock used f or receiving RSL signals from the
Channel. Negative polarity.
1Logic threshold reference vol tage for RSL signals.
Note2
1Clock to master. I nterface clock used f or transmitting RSL signal s to the Channel.
Negative polarity.
Note2
1Clock to master. I nterface clock used f or transmitting RSL signal s to the Channel.
Positive polarity.
Note2
3Row access control. Three pi ns containing control and address i nf orm ation for
row accesses.
Note2
5Column access control . Five pins containing control and address information for
column accesses.
Note2
8Data byte B. Eight pi ns whi ch carry a byte of read or write dat a between the
Channel and the RDRAM.
488448 for Rev. P
PD
Notes 1.
All CMOS signals are high-true ; a high voltage is a logic one and a low voltage is logic zero.
All RSL signals are low-true ; a low voltage is a logic one and a high voltage is logic zero.
2.
Data Sheet M14837EJ3V0DS00
5
Block Diagram
PD488448 for Rev. P
µµµµ
RQ7..RQ5 or
ROW2..ROW0
88
3
CTMDQB7..DQB0DQA7..DQA0CTMN
RCLK
SCK, CMD2SIO0, SIO1
2
CFM CFMN
1:8 Demux
Packet Decode
ROWRROWA
11559
ROPAVDR BRRCMBMACOPSDC BCXOPMDX BX
Internal DQB Data Path
8
RCLK
8
1:8 Demux
DM
Row Decode
8
Write Buffer
Mux
Sense Amp
32x64
64
64
PRER
ACT
DRAM Core
32x64
0
SAmp
0/1
SAmp
1/2
SAmp
•
•
•
13/14
SAmp
14/15
SAmp
15
SAmp
TCLK
512x64x128
Control Registers
Power Modes
Bank 0
Bank 1
Bank 2
•
•
•
Bank 13
Bank 14
Bank 15
RCLK
6
5
DEVIDREFR
XOP Decode
PREX
32x64
0
0/1
1/2
13/14
14/15
15
Packet Decode
5
5
SAmp
64
SAmp
64
SAmp
•
•
•
SAmp
SAmp
SAmp
RQ4..RQ0 or
COL4..COL0
5
1:8 Demux
5
5
MatchMatchMatch
Write
Buffer
MuxMux
Column Decode & Mask
PRECRD, WR
Internal DQA Data Path
8
Write Buffer
RCLK
COLMCOLCCOLX
6
8
8
8
RCLK
1:8 Demux
8
SAmp
16
SAmp
16/17
SAmp
TCLK
17/18
SAmp
•
8
•
•
8:1 Mux
29/30
SAmp
30/31
SAmp
31
SAmp
6
Data Sheet M14837EJ3V0DS00
Bank 16
Bank 17
Bank 18
•
•
•
Bank 29
Bank 30
Bank 31
16
16/17
17/18
29/30
30/31
31
SAmp
SAmp
•
•
•
SAmp
SAmp
SAmp
88
TCLK
8:1 Mux
8
488448 for Rev. P
µµµµ
PD
CONTENTS
1. General Description.................................................................................................................................................9
2. Packet Format ........................................................................................................................................................11
3. Field Encoding Summary......................................................................................................................................13
5. COLM Packet to D Packet Mapping............................................................................................. .........................15
16. Interleaved Write - Example ................................................................................................................................30
17. Interleaved Read - Example ................................................................................................................................31
18. Interleaved RRWW - Example .............................................................................................................................32
19. Control Register Transactions............................................................................................................................33
20. Control Register Packets.....................................................................................................................................34
22. Control Register Summary..................................................................................................................................39
23. Power State Management....................................................................................................................................48
25. Current and Temperature Control ......................................................................................................................55
37. Absolute Maximum Ratings................................................................................................................................68
Data Sheet M14837EJ3V0DS00
7
PD488448 for Rev. P
µµµµ
38. IDD - Supply Current Profile..................................................................................................................................68
39. Capacitance and Inductance...............................................................................................................................69
40. Glossary of Terms................................................................................................................................................71
The figure on page 6 is a block diagram of the µPD488448. It consists of two major blocks : a “core” block built from
banks and sense amps similar to those found in other types of DRAM, and a Direct Rambus interface block which
permits an external controller to access this core at up to 1.6 GB/s.
Control Registers:
used to write and read a block of control registers. These registers supply the RDRAM configuration information to a
controller and they select the operating modes of the device. The nine bit REFR value is used for tracking the last
refreshed row. Most importantly, the five bits DEVID specifies the device address of the RDRAM on the Channel.
Clocking:
transmit read data. The CFM and CFMN pins (Clock-From-Master) generate RCLK (Receive Clock), the internal
clock signal used to receive write data and to receive the ROW and COL pins.
DQA, DQB Pins:
multiplexed from / to two 64-bit data paths (running at one-eighth the data frequency) inside the RDRAM.
Banks:
rows, with each row containing 64 dualocts, and each dualoct containing 16 bytes. A dualoct is the smallest unit of
data that can be addressed.
Sense Amps:
storage (256 for DQA and 256 for DQB) and can hold one-half of one row of one bank of the RDRAM. The sense
amp may hold any of the 512 half-rows of an associated bank. However, each sense amp is shared between two
adjacent banks of the RDRAM (except for numbers 0, 15, 16, and 31). This introduces the restriction that adjacent
banks may not be simultaneously accessed.
The CTM and CTMN pins (Clock-To-Master) generate TCLK (Transmit Clock), the internal clock used to
The 16 Mbyte core of the RDRAM is divided into two sets of sixteen 0.5 Mbyte banks, each organized as 512
The CMD, SCK, SIO0, and SIO1 pins appear in the upper center of the block diagram. They are
These 16 pins carry read (Q) and write (D) data across the Channel. They are multiplexed / de-
The RDRAM contains two sets of 17 sense amps. Each sense amp consists of 512 bytes of fast
RQ Pins:
called ROW2..ROW0, and are used primarily for controlling row accesses. RQ4..RQ0 are also called COL4..COL0,
and are used primarily for controlling column accesses.
ROW Pins:
amps of the RDRAM. These pins are de-multiplexed into a 24-bit ROWA (row-activate) or ROWR (row-operation)
packet.
COL Pins:
sense amps of the RDRAM. These pins are de-multiplexed into a 23-bit COLC (column-operation) packet and either
a 17-bit COLM (mask) packet or a 17-bit COLX (extended-operation) packet.
ACT Command:
bank to be loaded to its associated sense amps (two 256 byte sense amps for DQA and two for DQB).
PRER Command:
two associated sense amps, permitting a different row in that bank to be activated, or permitting adjacent banks to be
activated.
These pins carry control and address information. They are broken into two groups. RQ7..RQ5 are also
The principle use of these three pins is to manage the transfer of data between the banks and the sense
The principle use of these five pins is to manage the transfer of data between the DQA/DQB pins and the
An ACT (activate) command from an ROWA packet causes one of the 512 rows of the selected
A PRER (precharge) command from an ROWR packet causes the selected bank to release its
Data Sheet M14837EJ3V0DS00
9
PD488448 for Rev. P
µµµµ
RD Command:
on the DQA/DQB pins of the Channel.
WR Command:
be loaded into the write buffer. There is also space in the write buffer for the BC bank address and C column
address information. The data in the write buffer is automatically retired (written with optional bytemask) to one of the
64 dualocts of one of the sense amps during a subsequent COP command. A retire can take place during a RD, WR,
or NOCOP to another device, or during a WR or NOCOP to the same device. The write buffer will not retire during a
RD to the same device. The write buffer reduces the delay needed for the internal DQA/DQB data path turn-around.
PREC Precharge:
operation is scheduled at the end of the column operation. These commands provide a second mechanism for
performing precharge.
PREX Precharge:
be used to specify an extended operation (XOP). The most important XOP command is PREX. This command
provides a third mechanism for performing precharge.
The RD (read) command causes one of the 64 dualocts of one of the sense amps to be transmitted
The WR (write) command causes a dualoct received from the DQA/DQB data pins of the Channel to
The PREC, RDA and WRA commands are similar to NOCOP, RD and WR, except that a precharge
After a RD command, or after a WR command with no byte masking (M=0), a COLX packet may
10
Data Sheet M14837EJ3V0DS00
488448 for Rev. P
µµµµ
PD
2. Packet Format
Figure 2-1 shows the formats of the ROWA and ROWR packets on the ROW pins. Table 2-1 describes the fields
which comprise these packets. DR4T and DR4F bits are encoded to contain both the DR4 device address bit and a
framing bit which allows the ROWA or ROWR packet to be recognized by the RDRAM.
The AV (ROWA/ROWR packet selection) bit distinguishes between the two packet types. Both the ROWA and
ROWR packet provide a five bit device address and a four bit bank address. An ROWA packet uses the remaining
bits to specify a nine bit row address, and the ROWR packet uses the remaining bits for an eleven bit opcode field.
Note the use of the “RsvX” notation to reserve bits for future address field extension.
Figure 2-1 also shows the formats of the COLC, COLM, and COLX packets on the COL pins. Table 2-2 describes
the fields which comprise these packets.
The COLC packet uses the S (Start) bit for framing. A COLM or COLX packet is aligned with this COLC packet, and
is also framed by the S bit.
The 23 bit COLC packet has a five bit device address, a four bit bank address, a six bit column address, and a four
bit opcode. The COLC packet specifies a read or write command, as well as some power management commands.
The remaining 17 bits are interpreted as a COLM (M=1) or COLX (M=0) packet. A COLM packet is used for a
COLC write command which needs bytemask control. The COLM packet is associated with the COLC packet from a
time t
device address, a four bit bank address, and a five bit opcode. The COLX packet may also be used to specify some
housekeeping and power management commands. The COLX packet is framed within a COLC packet but is not
otherwise associated with any other packet.
earlier. An COLX packet may be used to specify an independent precharge command. It contains a five bit
RTR
Table 2-1 Field Description for ROWA Packet and ROWR Packet
FieldDescription
DR4T, DR4FBits for framing (recogni zing) a ROWA or ROWR packet. Als o encodes highest device address bit.
DR3..DR0Device address for ROWA or ROWR packet.
BR4..BR0Bank address for ROWA or ROWR pack et . RsvB denotes bits i gnored by the RDRAM.
AVSelects between ROWA packet (AV =1) and ROWR packet (AV=0).
R8..R0Row address for ROWA packet. RsvR denotes bits reserv ed f or future row address extension.
ROP10..ROP0Opcode field for ROWR packet. Specifies precharge, refres h, and power management functions.
Table 2-2 Field Description for COLC Packet, COLM Packet, and COLX Packet
FieldDescription
SBit for framing (recogniz i ng) a COLC packet, and indirectly f or framing COLM and COLX packets.
DC4..DC0Device address for COLC packet.
BC4..BC0Bank address for COLC packet . RsvB denotes bits res erved for future extension (controller drivers 0's).
C5..C0Column address for COLC packet. RsvC denotes bits ignored by t he RDRAM.
COP3..COP0Opcode field for COLC packet. Specifies read, write, prec harge, and power management functions.
MSelects between COLM pack et (M=1) and COLX packet (M=0).
MA7..MA0Bytemask write control bits. 1=write, 0=no-wri t e. MA0 controls the earliest byte on DQA7..0.
MB7..MB0Bytemask write control bits. 1=write, 0=no-wri t e. MB0 controls the earliest byte on DQB7..0.
DX4..DX0Device address for COLX packet.
BX4..BX0Bank address for COLX pack et . RsvB denotes bits res erved for future extension (c ontroller drivers 0's).
XOP4..XOP0Opcode field for COLX packet . Specifies precharge, IOL control, and power management functions.
Data Sheet M14837EJ3V0DS00
11
Figure 2-1 Packet Formats
PD488448 for Rev. P
µµµµ
CTM/CFM
ROW2
ROW1
ROW0
CTM/CFM
COL4
COL3
COL2
COL1
T
0
DR2 BR0 BR3 RsvR R8R5
DR4T
DR1 BR1 BR4 RsvR R7R4R1
DR4F
DR0 BR2 RsvB AV=1 R6R3R0
DR3
T
1
T
2
ROWA Packet
T
0
S=1RsvC
DC4
DC3
COP1RsvB BC2 C2
DC2
COP0 BC4 BC1 C1
DC1
T
1
T
2
T
3
R2
T
3
C4
C5C3
CTM/CFM
ROW2
ROW1
ROW0
CTM/CFM
ROW2
..ROW0
COL4
..COL0
DQA7..0
DQB7..0
T
8
DR2 BR0 BR3 ROP10ROP8ROP5
DR4T
DR1 BR1 BR4 ROP9ROP7ROP4ROP1
DR4F
DR0 BR2 RsvB AV=0 ROP6ROP3ROP0
DR3
T
9
T
10
ROWR Packet
T
0
T
T
1
ACT a0
WR b1
T
T
4
2
3
T
T
5
6
t
PACKET
T
7
T
T
8
PRER c0
T
11
ROP2
T
T
T
9
10
T
T
11
T
12
13
14
15
PREX d0MSK (b1)
COL0
CTM/CFM
COL4
COL3
COL2
COL1
COL0
COP2COP3 BC3 BC0 C0
DC0
COLC Packet
T
8
T
9
T
10
T
11
T
12
T
13
CTM/CFM
Note1
MA7 MA5 MA3 MA1
S=1
M=1 MA6 MA4 MA2 MA0
MB7 MB4 MB1
MB6 MB3 MB0
MB5 MB2
COL4
COL3
COL2
COL1
COL0
COLM Packet
Notes 1. The COLM is associated with a previous COLC, and is aligned with the present COLC, indicated
by the Start bit (S=1) position.
2. The COLX is aligned with the present COLC, indicates by the Start bit (S=1) position.
Note2
DX4 XOP4 RsvB BX1
S=1
M=0 DX3 XOP3 BX4 BX0
DX2 XOP2 BX3
DX1 XOP1 BX2
DX0 XOP0
COLX Packet
T
14
T
15
12
Data Sheet M14837EJ3V0DS00
488448 for Rev. P
µµµµ
PD
3. Field Encoding Summary
Table 3-1 shows how the six device address bits are decoded for the ROWA and ROWR packets. The DR4T and
DR4F encoding merges a fifth device bit with a framing bit. When neither bit is asserted, the device is not selected.
Note that a broadcast operation is indicated when both bits are set. Broadcast operation would typically be used for
refresh and power management commands. If the device is selected, the DM (DeviceMatch) signal is asserted and
an ACT or ROP command is performed.
Table 3-1 Device Field Encodings for ROWA Packet and ROWR Packet
DR4TDR4FDevice SelectionDevice Match signal (DM)
11All devices (broadcast)DM is set to 1
01One device selectedDM is set to 1 if {DEVID4..DEVID0} == {0, DR3..DR0} else DM is set to 0
10One device selectedDM is set to 1 if {DEVID4..DEVID0} == {1, DR3..DR0} else DM is set to 0
00No packet presentDM is set to 0
Table 3-2 shows the encodings of the remaining fields of the ROWA and ROWR packets. An ROWA packet is
specified by asserting the AV bit. This causes the specified row of the specified bank of this device to be loaded into
the associated sense amps.
An ROWR packet is specified when AV is not asserted. An 11 bit opcode field encodes a command for one of the
banks of this device. The PRER command causes a bank and its two associated sense amps to precharge, so
another row or an adjacent bank may be activated.
The REFA (refresh-activate) command is similar to the ACT command, except the row address comes from an
internal register REFR, and REFR is incremented at the largest bank address. The REFP (refresh-precharge)
command is identical to a PRER command.
The NAPR, NAPRC, PDNR, ATTN, and RLXR commands are used for managing the power dissipation of the
RDRAM and are described in more detail in “
23. Power State Management
used to adjust the output driver slew rate and they are described in more detail in “
Control
”.
”. The TCEN and TCAL commands are
25. Current and Temperature
Table 3-2 ROWA Packet and ROWR Packet Field Encodings
DM AVROP10..ROP0 FieldNameCommand Description
Note1
0 — ————— — —— --- —No operation.
11 Row addressACTActivat e row R8..R0 of bank BR4..BR0 of device and move device to
101 1000x
1 0 0001 100 x 000 REFARefresh (activate) row REFR8..REFR0 of bank BR4.. B R0 of device.
101010100x 000 REFPPrecharge bank BR4..BR0 of thi s device after REFA (see Fi gure 24-1).
1 0 xx000 01x 000 PDNRMove this devi ce into the powerdown (PDN) power state (see figure 23-3).
1 0 xx000 10x 000 NAPRM ove this device into t he nap (NA P) power state (see Figure 23-3).
1 0 xx000 11x 000 NAPRCMove this dev i ce into the nap (NAP) power state conditionally.
1 0 xxxxx x x0 000
1 0 xxxxx x x1 000 RLXRMove this device i nt o the standby (STBY) power st at e (see Figure 23-2).
1 0 00000 0 0x001 TCALTemperature calibrate this device (see figure 25-2).
1 0 00000 0 0x010 TCENTemperature calibrate/enable this device (see Figure 25-2).
1 0 00000 0 00000NOROP No operat i on.
Notes 1.
2.
3.
be
109876 5 432 : 0
Note2
Note3
xx 000 PRERPrecharge bank BR4..BR0 of this dev i ce.
ATTN
The DM (Device Match signal ) value is determined by the DR4T, DR4F, DR3..DR0 field of the ROWA and ROWR pac kets.
See Table 3-1.
The ATTN command does not cause a RLX -to-ATTN transition for a broadcas t operation (RD4T/DR4F=1/1).
An “x” entry indicates whi ch commands may be combined. For instance, the three c om m ands PRER/NAPRC/RLXR may
specified in one ROP value (011000111000).
ATTN
Increment REFR if BR4..BR0=11111 (see Figure 24-1).
Note2
Move this device into the attention (ATTN) power stat e (see Figure 23-1).
.
Data Sheet M14837EJ3V0DS00
13
PD488448 for Rev. P
µµµµ
Table 3-3 shows the COP field encoding. The device must be in the ATTN power state in order to receive COLC
packets. The COLC packet is used primarily to specify RD (read) and WR (write) commands. Retire operations
(moving data from the write buffer to a sense amp) happen automatically. See Figure 15-1 for a more detailed
description.
The COLC packet can also specify a PREC command, which precharges a bank and its associated sense amps.
The RDA/WRA commands are equivalent to a combining RD/WR with a PREC. RLXC (relax) performs a power mode
transition. See
23. Power State Management
.
Table 3-3 COLC Packet Field Encodings
SDC4..DC0
(select device)
0- - - - - - - - -—No operation.
1/= (DEVID4..0) - - - - -—Retire write buffer of this device.
1== (DEVID4..0)
1== (DEVID4..0) x001WRRetire write buffer of this devi ce, then write column C5.. C0 of bank
1== (DEVID4..0) x010RSRVReserved, no operation.
1== (DEVID4..0) x011RDRead column C5..C0 of bank BC4..BC0 of this device.
1== (DEVID4..0) x100PRECRetire write buffer of thi s device, then precharge bank BC4..BC0 (see
1== (DEVID4..0) x101WRASame as WR, but precharge bank BC4..BC0 aft er wri t e buffer (with new
1== (DEVID4..0) x110RSRVReserved, no operation.
1== (DEVID4..0) x111RDASame as RD, but precharge bank BC4..BC0 afterward.
1== (DEVID4..0) 1xxxRLXCMove this device i nto the standby (STBY) power s t ate (see Figure 23-2).
Notes 1.
2.
“/=” means not equal, “==” means equal.
An “x” entry indicates which commands may be combined. For instance, the two commands WR/RLXC
COP3..0NameCommand Description
Note1
Note2
x000
NOCOPRetire write buffer of this device.
BC4..BC0 to write buffer.
Figure 12-2).
data) is retired.
may be specified in one COP value(1001).
Table 3-4 shows the COLM and COLX field encodings. The M bit is asserted to specify a COLM packet with two 8
bit bytemask fields MA and MB. If the M bit is not asserted, an COLX is specified. It has device and bank address
fields, and an opcode field. The primary use of the COLX packet is to permit an independent PREX (precharge)
command to be specified without consuming control bandwidth on the ROW pins. It is also used for the CAL
(calibrate) and SAM (sample) current control commands (see
RLXX power mode command (see
23. Power State Management
25. Current and Temperature Control
).
), and for the
Table 3-4 COLM Packet and COLX Packet Field Encodings
MDX4..DX0
(select device)
1- - - - -MSKMB/MA bytemasks used by WR/WRA.
0/= (DEVID4.. 0) -—No operation.
0== (DEVID4..0) 00000NOXOPNo operation.
0== (DEVID4..0)
0== (DEVID4..0) x10x0CALCalibrate (drive) IOL current for this devic e (see Figure 25-1).
0== (DEVID4..0) x11x0CAL / SAM Calibrate (drive) and Sample (update) IOL current for this devic e (see Figure 25-1).
0== (DEVID4..0) xxx10RLXXMove this device into the standby (STBY) power state (see Figure 23-2).
0== (DEVID4..0) xxxx1RSRVReserved, no operation.
An “x” entry indicates which commands may be combined. For instance, the two commands PREX/RLXX
Note
XOP4..0 NameCommand Description
Note
1xxx0
PREXPrecharge bank BX4.. BX0 of this device (s ee Fi gure 12-2).
may be specified in one XOP value (10010).
14
Data Sheet M14837EJ3V0DS00
488448 for Rev. P
µµµµ
PD
4. DQ Packet Timing
Figure 4-1 shows the timing relationship of COLC packets with D and Q data packets. This document uses a
specific convention for measuring time intervals between packets: all packets on the ROW and COL pins (ROWA,
ROWR, COLC, COLM, COLX) use the trailing edge of the packet as a reference point, and all packets on the
DQA/DQB pins (D and Q) use the leading edge of the packet as a reference point.
An RD or RDA command will transmit a dualoct of read data Q a time t
cycles of round-trip propagation delay on the Channel. The t
of values (7, 8, 9, 10, 11, or 12 t
). The value chosen depends upon the number of RDRAM devices on the
CYCLE
Channel and the RDRAM timing bin. See Figure 22-1(5/7) “
parameter may be programmed to a one of a range
CAC
TPARM Register
A WR or WRA command will receive a dualoct of write data D a time t
the round-trip propagation time of the Channel since the COLC and D packets are traveling in the same direction.
When a Q packet follows a D packet (shown in the left half of the figure), a gap (t
between them because the t
value is always less than the t
CWD
value. There will be no gap between the two COLC
CAC
packets with the WR and RD commands which schedule the D and Q packets.
When a D packet follows a Q packet (shown in the right half of the figure), no gap is needed between them because
the t
value is less than the t
CWD
value. However, a gap of t
CAC
CAC
- t
CWD
COLC packets with the RD WR commands by the controller so the Q and D packets do not overlap.
later. This time includes one to five
CAC
” for more information.
later. This time does not need to include
CWD
CAC-tCWD
) will automatically appear
or greater must be inserted between the
Figure 4-1 Read (Q) and Write (D) Data Packet - Timing for t
T
T
T
T
T
1
2
3
0
4
T
T
T
T
5
6
7
T
T
8
T
T
9
T
T
10
T
11
15
12
T
13
14
T
T
T
T
17
18
19
16
20
T
T
21
T
T
22
T
T
23
T
25
26
27
24
= 7,8,9,10,11 or 12 t
CAC
T
T
T
T
T
29
28
T
30
31
33
32
CYCLE
T
T
T
34
35
36
T
T
T
T
37
38
39
T
T
41
40
T
T
42
T
T
T
45
46
43
47
44
CTM/CFM
ROW2
..ROW0
COL4
..COL0
DQA7..0
This gap on the DQA/DQB pins appears automatically
t
CAC-tCWD
t
CWD
RD b1WR a1
D (a1)
•••
Q (b1)
This gap on the COL pins must be inserted by the controller
t
CAC-tCWD
•••
RD c1
WR d1
t
CWD
Q (c1)
D (d1)
DQB7..0
t
CAC
•••
•••
t
CAC
5. COLM Packet to D Packet Mapping
Figure 5-1 shows a write operation initiated by a WR command in a COLC packet. If a subset of the 16 bytes of
write data are to be written, then a COLM packet is transmitted on the COL pins a time t
containing the WR command. The M bit of the COLM packet is set to indicate that it contains the MA and MB mask
fields. Note that this COLM packet is aligned with the COLC packet which causes the write buffer to be retired. See
Figure 15-1 for more details.
If all 16 bytes of the D data packet are to be written, then no further control information is required. The packet slot
that would have been used by the COLM packet (t
after the COLC packet) is available to be used as an COLX
RTR
packet. This could be used for a PREX precharge command or for a housekeeping command (this case is not
shown). The M bit is not asserted in an COLX packet and causes all 16 bytes of the previous WR to be written
unconditionally. Note that a RD command will never need a COLM packet, and will always be able to use the COLX
packet option (a read operation has no need for the byte-write-enable control bits).
The figure 5-1 also shows the mapping between the MA and MB fields of the COLM packet and bytes of the D
packet on the DQA and DQB pins. Each mask bit controls whether a byte of data is written (=1) or not written (=0).
after the COLC packet
RTR
Data Sheet M14837EJ3V0DS00
15
PD488448 for Rev. P
µµµµ
Figure 5-1 Mapping between COLM Packet and D Packet for WR Command
When M=1, the MA and MB
fields control writing of
individual data bytes.
When M=0, all data bytes are
written unconditionally.
MB6 MB3 MB0
MB5 MB2
Each bit of the MB7..MB0 field
controls writing (=1) or no writing
(=0) of the indicated DB bits when
the M bit of the COLM packet is one.
Each bit of the MA7..MA0 field
controls writing (=1) or no writing
(=0) of the indicated DA bits when
the M bit of the COLM packet is one.
DQB1
DQB0
DQA7
DQA6
•
•
•
DQA1
DQA0
DB9 DB17 DB25 DB33 DB41 DB49 DB57
DB1
DB8 DB16 DB24 DB32 DB40 DB48 DB56
DB0
MB0
MB1
MB2
MB3
MB4
MB5
DA15 DA23 DA31 DA39 DA47 DA55
DA7
DA14 DA22 DA30 DA38 DA46 DA54 DA64
DA6
DA9 DA17 DA25 DA33 DA41 DA49 DA57
DA1
DA8 DA16 DA24 DA32 DA40 DA48 DA56
DA0
MA0
MA1
MA2
MA3
MA4
MA5
MB6
MA6
MB7
DA63
MA7
16
Data Sheet M14837EJ3V0DS00
6. ROW-to-ROW Packet Interaction
488448 for Rev. P
µµµµ
PD
Figure 6-1 shows two packets on the ROW pins separated by an interval t
which depends upon the packet
RRDELAY
contents. No other ROW packets are sent to banks {Ba, Ba+1, Ba-1} between packet “a” and packet “b” unless
noted otherwise.
Figure 6-1 ROW-to-ROW Packet Interaction - Timing
T
0
T
T
T
T
1
2
3
4
T
T
T
T
5
6
7
T
T
9
8
T
T
10
T
T
11
T
12
16
T
13
14
15
T17T18T
T
19
CTM/CFM
t
ROW2
ROPa a0ROPb b0
RRDELAY
..ROW0
COL4
..COL0
DQA7..0
DQB7..0
Transaction a: ROPa
Transaction b: ROPb
Table 6-1 summarizes the t
RRDELAY
values for all possible cases.
Cases RR1 through RR4 show two successive ACT commands. In case RR1, there is no restriction since the ACT
commands are to different devices. In case RR2, the t
RR
banks. Cases RR3 and RR4 are illegal (as shown) since bank Ba needs to be precharged. If a PRER to Ba, Ba+1,
or Ba-1 is inserted, t
RRDELAY
is tRC (t
to the PRER command, and tRP to the next ACT).
RAS
Cases RR5 through RR8 show an ACT command followed by a PRER command. In cases RR5 and RR6, there are
no restrictions since the commands are to different devices or to non-adjacent banks of the same device. In cases
RR7 and RR8, the t
restriction means the activated bank must wait before it can be precharged.
RAS
Cases RR9 through RR12 show a PRER command followed by an ACT command. In cases RR9 and RR10, there
are essentially no restrictions since the commands are to different devices or to non-adjacent banks of the same
device. RR10a and RR10b depend upon whether a bracketed bank (Ba+-1) is precharged or activated. In cases
RR11 and RR12, the same and adjacent banks must all wait t
being activated.
Cases RR13 through RR16 summarize the combinations of two successive PRER commands. In case RR13 there
is no restriction since two devices are addressed. In RR14, t
RR15 and RR16, the same bank or an adjacent bank may be given repeated PRER commands with only the t
restriction.
Two adjacent banks can’t be activate simultaneously. A precharge command to one bank will thus affect the state of
the adjacent banks (and sense amps). If bank Ba is activate and a PRER is directed to Ba, then bank Ba will be
precharged along with sense amps Ba-1/Ba and Ba/Ba+1. If bank Ba+1 is activate and a PRER is directed to Ba,
then bank Ba+1 will be precharged along with sense amps Ba/Ba+1 and Ba+1/Ba+2. If bank Ba-1 is activate and a
PRER is directed to Ba, then bank Ba-1 will be precharged along with sense amps Ba/Ba-1 and Ba-1/Ba-2.
A ROW packet may contain commands other than ACT or PRER. The REFA and REFP commands are equivalent
to ACT and PRER for interaction analysis purposes. The interaction rules of the NAPR, NAPRC, PDNR, RLXR,
ATTN, TCAL, and TCEN commands are discussed in later section (see Table 3-2 for cross-ref).
a0 = {Da,Ba,Ra}
b0= {Db,Bb,Rb}
restriction applies to the same device with non-adjacent
for the sense amp and bank to precharge before
RP
applies, since the same device is addressed. In
PP
PP
Data Sheet M14837EJ3V0DS00
17
Table 6-1 ROW-to-ROW Packet Interaction - Rules
PD488448 for Rev. P
µµµµ
Case #ROPaDaBaRaROPbDb BbRbt
RR1ACTDaBaRaACT/= Da xxxxx..x t
RR2ACTDaBaRaACT== Da /= {Ba, B a+1, Ba-1}x..x t
RR3ACTDaBaRaACT== Da == {Ba+1, Ba-1}x..x t
RR4ACTDaBaRaACT== Da == {Ba}x..x t
RR5ACTDaBaRaPRER /= Da xxxxx..x t
RR6ACTDaBaRaPRER == Da /= {Ba, Ba+1, Ba-1}x..x t
RR7ACTDaBaRaPRER == Da == {Ba+1, Ba-1}x..x t
RR8ACTDaBaRaPRER == Da == {Ba}x..x t
RR9PRER DaBaRaACT/= Da xxxxx..x t
RR10PRER DaBaRaACT== Da /= {Ba, Ba+-1, Ba+-2} x..x t
RR10aPRER DaBaRaACT== Da == {Ba+2}x..x t
RR10bPRER DaBaRaACT== Da == {Ba-2}x..x t
RR11PRER DaBaRaACT== Da == {Ba+1, Ba-1}x..x t
RR12PRER DaBaRaACT== Da == {Ba}x..x t
RR13PRER DaBaRaPRER /= Da xxxxx..x t
RR14PRER DaBaRaPRER == Da / = {Ba, Ba+1, Ba-1}x..x t
RR15PRER DaBaRaPRER == Da == {Ba+1, B a-1}x..x t
RR16PRER DaBaRaPRER == Da == {Ba}x..x t
RRDELAY
PACKET
RR
RC
RC
PACKET
PACKET
RAS
RAS
PACKET
PACKET
PACKET/tRP
PACKET/tRP
RP
RP
PACKET
PP
PP
PP
Example
Figure 10-2
Figure 10-2
- illegal unless PRER to Ba / Ba+1 / Ba-1 Figure 10-1
Figure 7-1 shows two packets on the ROW and COL pins. They must be separated by an interval t
RCDELAY
which
depends upon the packet contents.
Figure 7-1 ROW-to-COL Packet Interaction- Timing
T
0
T
T
T
T
1
2
3
4
T
T
T
T
5
6
7
T
T
9
8
T
T
10
T
T
11
T
12
16
T
13
14
15
T17T18T
T
19
CTM/CFM
t
ROW2
ROPa a0
RCDELAY
..ROW0
COL4
COPb b1
..COL0
DQA7..0
DQB7..0
Transaction a: ROPa
Transaction b: COPb
Table 7-1 summarizes the t
RCDELAY
values for all possible cases. Note that if the COL packet is earlier than the
ROW packet, it is considered a COL-to-ROW packet interaction.
Cases RC1 through RC5 summarize the rules when the ROW packet has an ACT command. Figure 13-1 and
Figure 14-1 show examples of RC5 - an activation followed by a read or write. RC4 is an illegal situation, since a
read or write of a precharged banks is being attempted (remember that for a bank to be activated, adjacent banks
must be precharged). In cases RC1, RC2, and RC3, there is no interaction of the ROW and COL packets.
Cases RC6 through RC8 summarize the rules when the ROW packet has a PRER command. There is either no
interaction (RC6 through RC9) or an illegal situation with a read or write of a precharged bank (RC9).
The COL pins can also schedule a precharge operation with a RDA, WRA, or PREC command in a COLC packet or
a PREX command in a COLX packet. The constraints of these precharge operations may be converted to equivalent
PRER command constraints using the rules summarized in Figure 12-2.
COL pins. Packets “b” and “c” must be separated by
an interval t
CCDELAY
which depends upon the
command and address values in all three packets.
Table 8-1 summarizes the t
CCDELAY
values for all
possible cases.
Cases CC1 through CC5 summarize the rules for
every situation other than the case when COPb is a
WR command and COPc is a RD command. In
CTM/CFM
ROW2
..ROW0
COL4
..COL0
T
0
COPa a1
T
T
1
T
T
T
2
3
4
t
CCDELAY
COPb b1
T
T
T
5
6
7
8
T
T
9
T
T
10
T
11
T
13
14
12
COPc c1
T
T
15
16
T17T18T
T
19
CC3, when a RD command is followed by a WR
command, a gap of t
CAC - tCWD
between the two COL packets. See Figure 4-1 for
more explanation of why this gap is needed. For
cases CC1, CC2, CC4, and CC5, there is no
restriction (t
CCDELAY
is tCC).
In cases CC6 through CC10, COPb is a WR command and COPc is a RD command. The t
must be inserted
DQA7..0
DQB7..0
Transaction a: COPa
Transaction b: COPb
Transaction c: COPc
a1 = {Da,Ba,Ca1}
b1 = {Db,Bb,Cb1}
c1 = {Dc,Bc,Cc1}
CCDELAY
value needed
between these two packets depends upon the command and address in the packet with COPa. In particular, in case
CC6 when there is WR-WR-RD command sequence directed to the same device, a gap will be needed between the
packets with COPb and COPc. The gap will need a COLC packet with a NOCOP command directed to any device in
order to force an automatic retire to take place. Figure 15-2 (right) provides a more detailed explanation of this case.
In case CC10, there is a RD-WR-RD sequence directed to the same device. If a prior write to the same device is
unretired when COPa is issued, then a gap will be needed between the packets with COPb and COPc as in case
CC6. The gap will need a COLC packet with a NOCOP command directed to any device in order to force an
automatic retire to take place.
Cases CC7, CC8, and CC9 have no restriction (t
CCDELAY
is tCC).
For the purposes of analyzing COL-to-ROW interactions, the PREC, WRA, and RDA commands of the COLC
packet are equivalent to the NOCOP, WR, and RD commands. These commands also cause a precharge operation
PREC to take place. This precharge may be converted to an equivalent PRER command on the ROW pins using the
rules summarized in Figure 12-2.
Table 8-1 COL-to-COL Packet Interaction - Rules
Case # COPaDaBaCa1 COPbDbBbCb1 COPcDcBcCc1 t
CC1xxxxxxxxxx..x x..x NOCOP DbBbCb1 xxxxxxxxxx..x x..x t
CC2xxxxxxxxxx..x x..x RD, WR DbBbCb1 NOCOP xxxxxx..x x..x t
CC3xxxxxxxxxx..x x..x RDDbBbCb1 WRxxxxxx..x x..x t
CC4xxxxxxxxxx..x x..x RDDbBbCb1 RDxxxxxx..x x..x t
CC5xxxxxxxxxx..x x..x WRDbBbCb1 WRxxxxxx..x x..x t
CC6WR== Db xx..x WRDbBbCb1 RD== Dbx..x x. . x t
CC7WR== Db xx..x WRDbBbCb1 RD/= Dbx..x x..x t
CC8WR/= Dbxx..x WRDbBbCb1 RD== Dbx..x x..x t
CC9NOCOP == Db xx..x WRDbBbCb1 RD== Dbx..x x..x t
CC10RD== Db xx..x WRDbBbCb1 RD== Dbx..x x..x t
20
Data Sheet M14837EJ3V0DS00
CCDELAY
CC
CC
CC + tCAC - tCWD
CC
CC
RTR
CC
CC
CC
CC
Example
Figure 4-1
Figure 13-1
Figure 14-1
Figure 15-1
9. COL-to-ROW Packet Interaction
488448 for Rev. P
µµµµ
PD
Figure 9-1 shows arbitrary packets on the COL
and ROW pins. They must be separated by an
interval t
CRDELAY
which depends upon the
command and address values in the packets.
Table 9-1 summarizes the t
CRDELAY
value for all
possible cases.
Cases CR1, CR2, CR3, and CR9 show no
interaction between the COL and ROW packets,
either because one of the commands is a NOP or
Figure 9-1 COL-to-ROW Packet Interaction- Timing
T
T
T
T
T
1
2
3
0
4
T
T
T
T
5
6
7
T
T
9
8
T
T
10
T
T
T
T
13
11
12
T17T18T
14
15
16
CTM/CFM
t
CRDELAY
ROW2
ROPb b0
..ROW0
COL4
COPa a1
..COL0
T
19
because the packets are directed to different
devices or to non-adjacent banks.
DQA7..0
DQB7..0
Case CR4 is illegal because an already-activated
bank is to be re-activated without being
Transaction a: COPa
Transaction b: ROPb
a1= {Da,Ba,Ca1}
b0= {Db,Bb,Rb}
precharged. Case CR5 is illegal because an
adjacent bank can’t be activated or precharged
until bank Ba is precharged first.
In case CR6, the COLC packet contains a RD command, and the ROW packet contains a PRER command for the
same bank. The t
RDP
parameter specifies the required spacing.
Likewise, in case CR7, the COLC packet causes an automatic retire to take place, and the ROW packet contains a
PRER command for the same bank. The t
RTP
parameter specifies the required spacing.
Case CR8 is labeled “Hazardous” because a WR command should always be followed by an automatic retire before
a precharge is scheduled. Figure 15-3 shows an example of what can happen when the retire is not able to happen
before the precharge.
For the purposes of analyzing COL-to-ROW interactions, the PREC, WRA, and RDA commands of the COLC
packet are equivalent to the NOCOP, WR, and RD commands. These commands also cause a precharge operation
to take place. This precharge may converted to an equivalent PRER command on the ROW pins using the rules
summarized in Figure 12-2.
A ROW packet may contain commands other than ACT or PRER. The REFA and REFP commands are equivalent
to ACT and PRER for interaction analysis purposes. The interaction rules of the NAPR, PDNR, and RLXR
commands are discussed in a later section.
DaB aCa1PRER== Da== {Ba, Ba+1, Ba-1} x..x0Figure 15-3
CR9xxxxDaBaCa1NOROP xxxxxxxxxxx..x0
Notes 1.
This is any command which permits the write buffer of device Da to retire (see Table 3-3). “Ba” is the bank
address in the write buffer.
2.
This situation is hazardous because the write buffer will be left unretired while the targeted bank is
precharged. See Figure 15-3.
Data Sheet M14837EJ3V0DS00
CRDELAY
RDP
RTP
Example
Figure 13-1
Figure 14-1
21
PD488448 for Rev. P
µµµµ
10. ROW-to-ROW Examples
Figure 10-1 shows examples of some of the ROW-to-ROW packet spacings from Table 6-1. A complete sequence
of activate and precharge commands is directed to a bank. The RR8 and RR12 rules apply to this sequence. In
addition to satisfying the t
must also satisfy the t
RC
and t
RAS
timing parameter (RR4).
timing parameters, the separation between ACT commands to the same bank
RP
When a bank is activated, it is necessary for adjacent banks to remain precharged. As a result, the adjacent banks
will also satisfy parallel timing constraints; in the example, the RR11 and RR3 rules are analogous to the RR12 and
RR4 rules.
Figure 10-1 Row Packet Example
a0 = {Da,Ba,Ra}
Same DeviceAdjacent BankRR7
Same DeviceAdjacent BankRR11
T
0
T
T
T
T
1
2
3
4
T
T
T
T
5
6
7
T
T
8
T
T
9
T
T
10
T
11
15
12
16
T
13
14
T
T
T
T
17
18
19
T
T
T
T
21
22
23
20
T
T
25
24
T
T
T
T
26
T
27
31
28
32
T
29
30
T
T
33
T
T
34
T
T
37
35
36
a1 = {Da,Ba+1}
b0 = {Da,Ba+1,Rb}Same DeviceAdjacent BankRR3
b0 = {Da,Ba,Rb}Same DeviceSame BankRR4
b0 = {Da,Ba+1,Rb}
b0 = {Da,Ba,Rb}Same DeviceSame BankRR12
T
T
T
T
41
38
42
39
40
T
T
T
T
T
45
46
43
47
44
CTM/CFM
ROW2
ACT a0PRER a1
ACT b0
..ROW0
COL4
..COL0
t
RAS
t
RP
DQA7..0
DQB7..0
t
RC
Figure 10-2 shows examples of the ACT-to-ACT (RR1, RR2) and ACT-to-PRER (RR5, RR6) command spacings
from Table 6-1. In general, the commands in ROW packets may be spaced an interval t
apart unless they are
PACKET
directed to the same or adjacent banks or unless they are a similar command type (both PRER or both ACT)
directed to the same device.
Figure 10-2 Row Packet Example
Different DeviceAny Bank
Same DeviceNon-adjacent Bank
Different DeviceAny Bank
Same DeviceNon-adjacent Bank
T
T
T
T
T
1
2
3
0
T
T
T
T
5
6
7
4
T
T
8
T
T
9
T
T
10
T
11
15
12
16
T
13
14
T
T
T
T
17
18
19
T
T
T
T
21
22
23
20
T
T
24
T
T
25
T
T
26
T
27
31
28
T
29
30
T
T
33
32
T
T
T
37
34
35
36
RR1
RR2
RR5
RR6
T
38
T
39
a0 = {Da,Ba,Ra}
b0 = {Db,Bb,Rb}
c0 = {Da,Bc,Rc}
b0 = {Db,Bb,Rb}
c0 = {Da,Bc,Rc}
T
T
T
T
T
41
42
43
40
44
T
T
45
46
CTM/CFM
T
47
ROW2
..ROW0
COL4
..COL0
DQA7..0
DQB7..0
22
ACT a0PRER b0
t
PACKET
t
RR
ACT c0
ACT a0ACT a0ACT b0PRER c0
t
PACKET
Data Sheet M14837EJ3V0DS00
ACT a0
t
PACKET
488448 for Rev. P
µµµµ
PD
Figure 10-3 shows examples of the PRER-to-PRER (RR13, RR14) and PRER-to-ACT (RR9, RR10) command
spacings from Table 6-1. The RR15 and RR16 cases (PRER-to-PRER to same or adjacent banks) are not shown,
but are similar to RR14. In general, the commands in ROW packets may be spaced an interval t
PACKET
apart unless
they are directed to the same or adjacent banks or unless they are a similar command type (both PRER or both ACT)
directed to the same device.
sensing the value of a bit in a bank’s storage cell transfers the bit to the sense amp, but leaves the original bit in the
storage cell with an incorrect value.
A row cycle begins with the activate (ACT) operation. The activation process is destructive; the act of
47
Restore:
Because the activation process is destructive, a hidden operation called restore is automatically performed.
The restore operation rewrites the bits in the sense amp back into the storage cells of the activated row of the bank.
Read/Write:
While the restore operation takes place, the sense amp may be read (RD) and written (WR) using
column operations. If new data is written into the sense amp, it is automatically forwarded to the storage cells of the
bank so the data in the activated row and the data in the sense amp remain identical.
Precharge:
When both the restore operation and the column operations are completed, the sense amp and bank are
precharged (PRE). This leaves them in the proper state to begin another activate operation.
Intervals:
interval t
t
RCD,MIN
The activate operation requires the interval t
- t
RAS,MIN
interval (if more than about four column operations are performed, this interval must be increased). The
to complete. Column read and write operations are also performed during the t
RCD,MIN
precharge operation requires the interval t
Adjacent Banks:
An RDRAM with a “s” designation (256K
RP,MIN
to complete.
to complete. The hidden restore operation requires the
RCD,MIN
16 x 32s) indicates it contains “split banks”. This means
x
RAS,MIN
-
the sense amps are shared between two adjacent banks. The only exception is that sense amp 0, 15, 16, and 31 are
not shared. When a row in a bank is activated, the two adjacent sense amps are connected to (associated with) that
bank and are not available for use by the two adjacent banks. These two adjacent banks must remain precharged
while the selected bank goes through its activate, restore, read/write, and precharge operations.
For example (referring to the block diagram), if bank 5 is accessed, sense amp 4/5 and sense amp 5/6 will both be
loaded with one of the 512 rows (with 512 bytes loaded into each sense amp from the 1K byte row – 256 bytes to the
DQA side and 256 bytes to the DQB side). While this row from bank 5 is being accessed, no rows may be accessed
in banks 4 or 6 because of the sense amp sharing.
Data Sheet M14837EJ3V0DS00
23
PD488448 for Rev. P
µµµµ
12. Precharge Mechanisms
Figure 12-1 shows an example of precharge with the ROWR packet mechanism. The PRER command must occur
a time t
after the ACT command, and a time t
RAS
before the next ACT command. This timing will serve as a
RP
baseline against which the other precharge mechanisms can be compared.
Figure 12-1 Precharge via PRER Command in ROWR Packet
a0 = {Da,Ba,Ra}
a5 = {Da,Ba}
b0 = {Da,Ba,Rb}
T
0
T
T
T
T
1
2
3
4
T
T
T
T
5
6
7
T
T
8
T
T
9
T
T
10
T
11
15
12
16
T
13
14
T
T
T
T
17
18
19
20
T
T
T
T
21
22
23
T
T
25
24
T
T
T
T
26
T
27
31
28
32
T
29
30
T
T
T
T
33
34
35
T
T
T
T
37
38
39
36
T
T
40
T
T
41
T
T
42
T
45
46
43
44
CTM/CFM
47
ROW2
ACT a0PRER a5
ACT b0
..ROW0
COL4
..COL0
t
RAS
t
RP
DQA7..0
DQB7..0
t
RC
Figure 12-2 (top) shows an example of precharge with a RDA command. A bank is activated with an ROWA packet
on the ROW pins. Then, a series of four dualocts are read with RD commands in COLC packets on the COL pins.
The fourth of these commands is a RDA, which causes the bank to automatically precharge when the final read has
finished. The timing of this automatic precharge is equivalent to a PRER command in an ROWR packet on the ROW
pins that is offset a time t
from the COLC packet with the RDA command. The RDA command should be treated
OFFP
as a RD command in a COLC packet as well as a simultaneous (but offset) PRER command in an ROWR packet
when analyzing interactions with other packets.
Figure 12-2 (middle) shows an example of precharge with a WRA command. As in the RDA example, a bank is
activated with an ROWA packet on the ROW pins. Then, two dualocts are written with WR commands in COLC
packets on the COL pins. The second of these commands is a WRA, which causes the bank to automatically
precharge when the final write has been retired. The timing of this automatic precharge is equivalent to a PRER
command in an ROWR packet on the ROW pins that is offset a time t
from the COLC packet that causes the
OFFP
automatic retire. The WRA command should be treated as a WR command in a COLC packet as well as a
simultaneous (but offset) PRER command in an ROWR packet when analyzing interactions with other packets. Note
that the automatic retire is triggered by a COLC packet a time t
after the COLC packet with the WR command
RTR
unless the second COLC contains a RD command to the same device. This is described in more detail in Figure 15-
1.
Figure 12-2 (bottom) shows an example of precharge with a PREX command in an COLX packet. A bank is
activated with an ROWA packet on the ROW pins. Then, a series of four dualocts are read with RD commands in
COLC packets on the COL pins. The fourth of these COLC packets includes an COLX packet with a PREX
command. This causes the bank to precharge with timing equivalent to a PRER command in an ROWR packet on
the ROW pins that is offset a time t
from the COLX packet with the PREX command.
OFFP
24
Data Sheet M14837EJ3V0DS00
Figure 12-2 Offsets for Alternate Precharge Mechanisms
COLC Packet: RDA Precharge Offset
CTM/CFM
ROW2
..ROW0
COL4
..COL0
T
0
T
T
T
T
1
2
3
4
T
T
T
T
5
6
7
T
T
8
T
T
9
T
T
13
10
14
11
12
The RDA precharge is equivalent to a PRER command here
ACT a0
RD a1
RD a2
488448 for Rev. P
µµµµ
PD
T
T
15
16
T
T
17
RD a3
T
T
18
19
20
T
T
T
T
21
22
23
T
25
24
PRER a5
T
T
T
T
T
26
T
27
31
28
32
T
29
30
T
T
T
T
33
34
35
T
T
T
T
37
38
39
36
T
T
40
T
T
41
T
T
42
T
45
46
43
47
44
ACT b0
t
OFFP
RDA a4
DQA7..0
DQB7..0
Transaction a: RDa0 = {Da,Ba,Ra}
COLC Packet: WDA Precharge Offset
CTM/CFM
ROW2
..ROW0
COL4
..COL0
DQA7..0
DQB7..0
T
0
T
T
T
T
1
2
3
4
T
T
T
T
5
6
7
T
T
8
T
T
9
T
T
10
T
13
14
11
15
12
The WRA precharge (triggered by the automatic retire) is equivalent to a PRER command here
Figure 13-1 shows an example of a read transaction. It begins by activating a bank with an ACT a0 command in an
ROWA packet. A time t
includes the device, bank, and row address (abbreviated as a0) while the RD command includes device, bank, and
column address (abbreviated as a1). A time t
the device. Note that the packets on the ROW and COL pins use the end of the packet as a timing reference point,
while the packets on the DQA/DQB pins use the beginning of the packet as a timing reference point.
A time t
after the first COLC packet on the COL pins a second is issued. It contains a RD a2 command. The a2
CC
address has the same device and bank address as the a1 address (and a0 address), but a different column address.
A time t
after the second RD command a second read data dualoct Q(a2) is returned by the device.
CAC
Next, a PRER a3 command is issued in an ROWR packet on the ROW pins. This causes the bank to precharge so
that a different row may be activated in a subsequent transaction or so that an adjacent bank may be activated. The
a3 address includes the same device and bank address as the a0, a1, and a2 addresses. The PRER command
must occur a time t
RAS
and the contents of the selected row must be restored from the two associated sense amps of the bank during the
t
interval). The PRER command must also occur a time t
RAS
t
value shown is greater than the t
RDP
two dualocts, but there is actually enough time to read three dualocts before t
rather than t
. If four dualocts were read, the packet with PRER would need to shift right (be delayed) by one t
RAS
(note-this case is not shown).
Finally, an ACT b0 command is issued in an ROWR packet on the ROW pins. The second ACT command must
occur a time t
or more after the first ACT command and a time t
RC
that the bank and its associated sense amps are precharged. This example assumes that the second transaction
has the same device and bank address as the first transaction, but a different row address. Transaction b may not
be started until transaction a has finished. However, transactions to other banks or other devices may be issued
during transaction a.
later a RD a1 command is issued in a COLC packet. Note that the ACT command
RCD
after the RD command the read data dualoct Q (a1) is returned by
CAC
or more after the original ACT command (the activation operation in any DRAM is destructive,
Figure 14-1 shows an example of a write transaction. It begins by activating a bank with an ACT a0 command in an
ROWA packet. A time t
measured to the end of the COLC packet with the first retire command). Note that the ACT command includes the
device, bank, and row address (abbreviated as a0) while the WR command includes device, bank, and column
address (abbreviated as a1). A time t
the packets on the ROW and COL pins use the end of the packet as a timing reference point, while the packets on
the DQA/DQB pins use the beginning of the packet as a timing reference point.
A time t
after the first COLC packet on the COL pins a second COLC packet is issued. It contains a WR a2
CC
command. The a2 address has the same device and bank address as the a1 address (and a0 address), but a
different column address. A time t
A time t
after each WR command an optional COLM packet MSK (a1) is issued, and at the same time a COLC
RTR
packet is issued causing the write buffer to automatically retire. See Figure 15-1 for more detail on the write/retire
mechanism. If a COLM packet is not used, all data bytes are unconditionally written. If the COLC packet which
causes the write buffer to retire is delayed, then the COLM packet (if used) must also be delayed.
Next, a PRER a3 command is issued in an ROWR packet on the ROW pins. This causes the bank to precharge so
that a different row may be activated in a subsequent transaction or so that an adjacent bank may be activated. The
a3 address includes the same device and bank address as the a0, a1, and a2 addresses. The PRER command
must occur a time t
RAS
and the contents of the selected row must be restored from the two associated sense amps of the bank during the
t
interval).
RAS
A PRER a3 command is issued in an ROWR packet on the ROW pins. The PRER command must occur a time t
or more after the last COLC which causes an automatic retire.
Finally, an ACT b0 command is issued in an ROWR packet on the ROW pins. The second ACT command must
occur a time t
or more after the first ACT command and a time t
RC
that the bank and its associated sense amps are precharged. This example assumes that the second transaction
has the same device and bank address as the first transaction, but a different row address. Transaction b may not
be started until transaction a has finished. However, transactions to other banks or other devices may be issued
during transaction a.
- t
RCD
or more after the original ACT command (the activation operation in any DRAM is destructive,
later a WR a1 command is issued in a COLC packet (note that the t
RTR
after the WR command the write data dualoct D(a1) is issued. Note that
CWD
after the second WR command a second write data dualoct D(a2) is issued.
CWD
or more after the PRER command. This ensures
RP
interval is
RCD
RTP
CTM/CFM
ROW2
..ROW0
COL4
..COL0
DQA7..0
DQB7..0
Figure 14-1 Write Transaction Example
T
T
T
1
0
ACT a0
T
T
2
3
T
T
T
T
5
6
7
4
T
T
8
T
T
9
t
T
10
RCD
T
13
11
12
WR a2
t
Transaction a: WR
Transaction b: xx b0 = {Da,Ba,Rb}
The process of writing a dualoct into a sense amp of an RDRAM bank occurs in two steps. The first step consists of
transporting the write command, write address, and write data into the write buffer. The second step happens when
the RDRAM automatically retires the write buffer (with an optional bytemask) into the sense amp. This two-step write
process reduces the natural turn-around delay due to the internal bidirectional data pins.
Figure 15-1 (left) shows an example of this two step process. The first COLC packet contains the WR command
and an address specifying device, bank and column. The write data dualoct follows a time t
information is loaded into the write buffer of the specified device. The COLC packet which follows a time t
will retire the write buffer. The retire will happen automatically unless (1) a COLC packet is not framed (no COLC
packet is present and the S bit is zero), or (2) the COLC packet contains a RD command to the same device. If the
retire does not take place at time t
after the original WR command, then the device continues to frame COLC
RTR
packets, looking for the first that is not a RD directed to itself. A bytemask MSK(a1) may be supplied in a COLM
packet aligned with the COLC that retires the write buffer at time t
after the WR command.
RTR
The memory controller must be aware of this two-step write/retire process. Controller performance can be
improved, but only if the controller design accounts for several side effects.
Figure 15-1 (right) shows the first of these side effects. The first COLC packet has a WR command which loads the
address and data into the write buffer. The third COLC causes an automatic retire of the write buffer to the sense
amp. The second and fourth COLC packets (which bracket the retire packet) contain RD commands with the same
device, bank and column address as the original WR command. In other words, the same dualoct address that is
written is read both before and after it is actually retired. The first RD returns the old dualoct value from the sense
amp before it is overwritten. The second RD returns the new dualoct value that was just written.
later. This
CWD
RTR
later
Figure 15-1 Normal Retire (left) and Retire/Read Ordering (right)
CTM/CFM
ROW2
..ROW0
COL4
..COL0
DQA7..0
DQB7..0
T
0
Transaction a: WRa1= {Da,Ba,Ca1}
T
T
T
T
1
2
3
4
Retire is automatic here unless:
(1) No COLC packet (S=0) or
T
T
T
T
5
6
7
T
T
8
T
T
9
T
T
13
10
11
12
(2) COLC packet is RD to device Da
WR a1
t
CWD
t
RTR
retire (a1)
MSK (a1)
D (a1)
T
T
14
15
T
T
T
T
17
18
19
16
CTM/CFM
ROW2
..ROW0
COL4
..COL0
DQA7..0
DQB7..0
T
T
T
T
21
22
23
20
0
T
T
T
T
1
2
3
4
T
T
T
T
5
6
7
T
T
8
T
T
9
10
T
T
T
T
13
11
12
T
14
15
17
16
This RD gets the old dataThis RD gets the new data
t
WR a1
RD b1RD c1
t
t
CWD
Transaction a: WR
Transaction b: RD
Transaction c: RD
RTR
CAC
retire (a1)
MSK (a1)
D (a1)
a1= {Da,Ba,Ca1}
b1= {Da,Ba,Ca1}
c1= {Da,Ba,Ca1}
Q (b1)
T
T
T
18
T
19
t
CAC
T
T
21
22
23
20
Figure 15-2 (left) shows the result of performing a RD command to the same device in the same COLC packet slot
that would normally be used for the retire operation. The read may be to any bank and column address; all that
matters is that it is to the same device as the WR command. The retire operation and MSK(a1) will be delayed by a
time t
as a result. If the RD command used the same bank and column address as the WR command, the old
PACKET
data from the sense amp would be returned. If many RD commands to the same device were issued instead of the
single one that is shown, then the retire operation would be held off an arbitrarily long time. However, once a RD to
another device or a WR or NOCOP to any device is issued, the retire will take place. Figure 15-2 (right) illustrates a
situation in which the controller wants to issue a WR-WR-RD COLC packet sequence, with all commands addressed
to the same device, but addressed to any combination of banks and columns.
The RD will prevent a retire of the first WR from automatically happening. But the first dualoct D(a1) in the write
Q
28
Data Sheet M14837EJ3V0DS00
488448 for Rev. P
0
µµµµ
PD
buffer will be overwritten by the second WR dualoct D(b1) if the RD command is issued in the third COLC packet.
Therefore, it is required in this situation that the controller issue a NOCOP command in the third COLC packet,
delaying the RD command by a time of t
t
CCDELAY
is equal to t
RTR
.
. This situation is explicitly shown in Table 8-1 for the cases in which
PACKET
Figure 15-2 Retire Held Off by Read (left) and Controller Forces WWR Gap (right)
T
CTM/CFM
ROW2
..ROW0
COL4
..COL0
DQA7..0
DQB7..0
T
T
T
T
1
2
3
0
4
The retire operation for a write can be
held off by a read to the same device
WR a1
T
T
T
T
5
6
7
T
8
RD b1
T
T
T
T
9
10
11
12
retire (a1)
MSK (a1)
t
+ t
RTR
PACKET
D (a1)
t
Transaction a: WR
Transaction b: RD
CWD
a1= {Da,Ba,Ca1}
b1= {Da,Bb,Cb1}
T
T
T
13
14
15
T
T
17
16
T
T
18
T
T
19
T
21
22
23
20
T
0
T
T
T
T
1
2
3
4
T
T
T
T
5
6
7
T
T
8
T
T
9
T
T
10
T
11
15
12
T
13
14
T17T18T
16
T
19
2
CTM/CFM
The controller must insert a NOCOP to retire (a1)
ROW2
to make room for the data (b1) in the write buffer
..ROW0
t
CAC
COL4
..COL0
Q (b1)
DQA7..0
WR a1
WR b1
t
RTR
retire (a1)
MSK (a1)
RD c1
D (a1)
D (b1)
t
CAC
DQB7..0
t
Transaction a: WR
Transaction b: WR
CWD
a1= {Da,Ba,Ca1}
b1= {Da,Bb,Cb1}
Transaction c: RDc1= {Da,Bc,Cc1}
Figure 15-3 shows a possible result when a retire is held off for a long time (an extended version of Figure 15-2-left).
After a WR command, a series of six RD commands are issued to the same device (but to any combination of bank
and column addresses). In the meantime, the bank Ba to which the WR command was originally directed is
precharged, and a different row Rc is activated. When the retire is automatically performed, it is made to this new
row, since the write buffer only contains the bank and column address, not the row address. The controller can
insure that this doesn’t happen by never precharging a bank with an unretired write buffer. Note that in a system with
more than one RDRAM, there will never be more than two RDRAMs with unretired write buffers. This is because a
WR command issued to one device automatically retires the write buffers of all other devices written a time t
RTR
before or earlier.
CTM/CFM
ROW2
..ROW0
COL4
..COL0
DQA7..0
DQB7..0
Figure 15-3 Retire Held Off by Reads to Same Device, Write Buffer Retired to New Row
WARNING
This sequence is hazardous
and must be used with caution
c0 = {Da,Ba,Rc}
Data Sheet M14837EJ3V0DS00
T
T
T
T
T
45
46
43
47
44
29
PD488448 for Rev. P
µµµµ
16. Interleaved Write - Example
Figure 16-1 shows an example of an interleaved write transaction. Transactions similar to the one presented in
Figure 14-1 are directed to non-adjacent banks of a single RDRAM. This allows a new transaction to be issued once
every t
this sequence.
With two dualocts of data written per transaction, the COL, DQA, and DQB pins are fully utilized. Banks are
precharged using the WRA autoprecharge option rather than the PRER command in an ROWR packet on the ROW
pins.
In this example, the first transaction is directed to device Da and bank Ba. The next three transactions are directed
to the same device Da, but need to use different, non-adjacent banks Bb, Bc, Bd so there is no bank conflict. The
fifth transaction could be redirected back to bank Ba without interference, since the first transaction would have
completed by then (t
address (Ca1, Ca2, Cb1, Cb2, ...).
interval rather than once every t
RR
has elapsed). Each transaction may use any value of row address (Ra, Rb, ...) and column
RC
Figure 16-1 Interleaved Write Transaction with Two Dualoct Data Length
interval (four times more often). The DQ data pin efficiency is 100% with
Figure 17-1 shows an example of interleaved read transactions. Transactions similar to the one presented in Figure
13-1 are directed to non-adjacent banks of a single RDRAM. The address sequence is identical to the one used in
the previous write example. The DQ data pins efficiency is also 100%. The only difference with the write example
(aside from the use of the RD command rather than the WR command) is the use of the PREX command in a COLX
packet to precharge the banks rather than the RDA command. This is done because the PREX is available for a
readtransaction but is not available for a masked write transaction.
Figure 17-1 Interleaved Read Transaction with Two Dualoct Data Length
Figure 18-1 shows a steady-state sequence of 2-dualoct RD/RD/WR/WR.. transactions directed to non-adjacent
banks of a single RDRAM. This is similar to the interleaved write and read examples in Figure 16-1 and Figure 17-1
except that bubble cycles need to be inserted by the controller at read/write boundaries. The DQ data pin efficiency
for the example in Figure 18-1 is 32/42 or 76%. If there were more RDRAMs on the Channel, the DQ pin efficiency
would approach 32/34 or 94% for the two-dualoct RRWW sequence (this case is not shown).
In Figure 18-1, the first bubble type t
pins. This bubble accounts for the round-trip propagation delay that is seen by read data, and is explained in detail in
Figure 4-1. This bubble appears on the DQA and DQB pins as t
dualoct Q. This bubble also appears on the ROW pins as t
The second bubble type t
is inserted (as a NOCOP command) by the controller between a WR and RD
CBUB2
command on the COL pins when there is a WR-WR-RD sequence to the same device. This bubble enables write
data to be retired from the write buffer without being lost, and is explained in detail in Figure 15-2. There would be no
bubble if address c0 and address d0 were directed to different devices. This bubble appears on the DQA and DQB
pins as t
as t
RBUB2
between a write data dualoct D and read data dualoct Q. This bubble also appears on the ROW pins
DBUB2
.
is inserted by the controller between a RD and WR command on the COL
CBUB1
between a write data dualoct D and read data
DBUB1
.
RBUB1
CTM/CFM
ROW2
..ROW0
COL4
..COL0
DQA7..0
DQB7..0
T
T
T
1
0
t
CBUB2
RD z1RD z2
t
DBUB1
D (y2)
Figure 18-1 Interleaved RRWW Sequence with Two Dualoct Data Length
T
2
3
ACT a0
T
T
T
T
T
5
6
7
4
t
DBUB2
T
T
T
T
9
10
11
8
RD a1RD a2
T
T
T
13
12
t
RBUB1
T
14
15
T
T
16
T
T
T
17
21
18
19
20
ACT b0ACT c0
t
CBUB1
PREX z3
MSK (y2)
Q (z2)Q (z1)
T
22
T
T
23
24
WRA b2
PREX a3
T
25
T
26
Q (a2)Q (a1)
T
T
T
27
28
WR c1WR b1
MSK (b1)
29
T
30
T
T
31
32
t
RBUB2
WRA c2
MSK (b2)
T
T
T
T
33
T
T
37
34
35
36
Transaction e can use the
same bank as transaction a
The RDRAM has two CMOS input pins SCK and CMD and two CMOS input/output pins SIO0 and SIO1. These
provide serial access to a set of control registers in the RDRAM. These control registers provide configuration
information to the controller during the initialization process. They also allow an application to select the appropriate
operating mode of the RDRAM. SCK (serial clock) and CMD (command) are driven by the controller to all RDRAMs
in parallel. SIO0 and SIO1 are connected (in a daisy chain fashion) from one RDRAM to the next. In normal
operation, the data on SIO0 is repeated on SIO1, which connects to SIO0 of the next RDRAM (the data is repeated
from SIO1 to SIO0 for a read data packet). The controller connects to SIO0 of the first RDRAM.
Write and read transactions are each composed of four packets, as shown in Figure 19-1 and Figure 19-2. Each
packet consists of 16 bits, as summarized in Table 20-1 and Table 20-2. The packet bits are sampled on the falling
edge of SCK. A transaction begins with a SRQ (Serial Request) packet. This packet is framed with a 11110000
pattern on the CMD input (note that the CMD bits are sampled on both the falling edge and the rising edge of SCK).
The SRQ packet contains the SOP3..SOP0 (Serial Opcode) field, which selects the transaction type. The
SDEV5..SDEV0 (Serial Device address) selects one of the 32 RDRAMs. If SBC (Serial Broadcast) is set, then all
RDRAMs are selected. The SA (Serial Address) packet contains a 12 bit address for selecting a control register.
A write transaction has a SD (Serial Data) packet next. This contains 16 bits of data that is written into the selected
control register. A SINT (Serial Interval) packet is last, providing some delay for any side-effects to take place. A
read transaction has a SINT packet, then a SD packet. This provides delay for the selected RDRAM to access the
control register. The SD read data packet travels in the opposite direction (towards the controller) from the other
packet types. The SCK cycle time will accommodate the total delay.
SCK
CMD
1111
SIO0
SIO1
SCK
CMD
1111
SIO
SIO
Figure 19-1 Serial Write (SWR) Transaction to Control Register
Table 20-1 summarizes the formats of the four packet
types for control register transactions. Table 20-2
summarizes the fields that are used within the packets.
Figure 20-1 SETR, CLRR, SETF Transaction
SCK
T
4
T
20
Figure 20-1 shows the transaction format for the SETR,
CLRR, and SETF commands. These transactions consist
CMD
1111
0000
00000000...00000000
of a single SRQ packet, rather than four packets like the
SWR and SRD commands. The same framing sequence
on the CMD input is used, however. These commands are
used during initialization prior to any control register read
or write transactions.
SIO0
SIO1
SRQ packet - SETR/CLRR/SETF
The packet is repeated
from SIO0 to SIO1
SRQ packet - SETR/CLRR/SETF
Table 20-1 Control Register Packet Formats
SCK
Cycle
SIO0 or
SIO1
for SRQ
SIO0 or
SIO1
for SA
SIO0 or
SIO1
for SINT
SIO0 or
SIO1
for SD
SCK
Cycle
SIO0 or
SIO1
for SRQ
SIO0 or
SIO1
for SA
SIO0 or
SIO1
for SINT
0rsrvrsrv0SD158SOP1SA70SD7
1rsrvrsrv0SD149SOP0SA60SD6
2rsrvrsrv0SD1310SBCSA50SD5
3rsrvrsrv0SD1211SDEV4SA40SD4
4rsrvSA110SD1112SDEV3SA30SD3
5SDEV5SA100SD1013SDEV2SA20SD2
6SOP3SA90SD914SDEV1SA10SD1
7SOP2SA80SD815SDEV0SA00SD0
SIO0 or
SIO1
for SD
1
0
1
0
1
0
1
0
Table 20-2 Field Description for Control Register Packets
FieldDescription
rsrvReserved. Should be driven as “0” by controller.
SOP3..SOP00000 - SRD. Serial read of control register {SA11..SA0} of RDRAM {SDEV5. .SDEV0}.
0001 - SWR. Serial write of c ontrol register {SA11.. SA0} of RDRAM {SDEV5. .SDEV0}.
0010 - SETR. Set Reset bit, all control registers assume their reset val ues.
command.
0100 - SETF. Set fast (normal) c l ock mode. 4 t
SCYCLE
delay until next comm and.
1011 - CLRR. Clear Reset bit, all control registers retai n their reset values.
command.
1111 - NOP. No serial operation.
SDEV5..SDEV0Serial dev i c e. Compared to SDEVID5..S DEVID0 field of INIT c ontrol register field to sel ect the RDRAM to
which the transaction is directed.
SBCSerial broadcast. When set, RDRAMs ignore {SDEV5..S DEV0} for RDRAM select ion.
SA11..SA0Serial address. Selects whi ch control register of the selected RDRAM is read or written.
SD15..SD0Serial data. The 16 bits of data written to or read from t he selected control regist er of the selected RDRAM.
The SETR and CLRR commands must always be applied in two successive transact i ons to RDRAMs; i.e. t hey may not be
Note
used in isolation. This is called “SETR/CLRR Reset”.
Note
Note
16 t
4 t
SCYCLE
SCYCLE
delay until next
delay until CLRR
34
Data Sheet M14837EJ3V0DS00
21. Initialization
Figure 21-1 SIO Pin Reset Sequence
T
0
SCK
488448 for Rev. P
µµµµ
PD
T
16
1
0
CMD
SIO0
SIO1
00001100
00000000...00000000
0000000000000000
The packet is repeated
from SIO0 to SIO1
0000000000000000
1
0
1
0
1
0
Initialization refers to the process that a controller must go through after power is applied to the system or the system
is reset. The controller prepares the RDRAM sub-system for normal Channel operation by (primarily) using a
sequence of control register transactions on the serial CMOS pins. The following steps outline the sequence seen by
the various memory subsystem components (including the RDRAM components) during initialization. This sequence
is available in the form of reference code. Contact Rambus Inc. for more information.
1.0 Start Clocks
This step calculates the proper clock frequencies for PClk (controller logic), SynClk (RAC block), RefClk (DRCG
component), CTM (RDRAM component), and SCK (SIO block).
2.0 RAC Initialization
This step causes the INIT block to generate a sequence of pulses which resets the RAC, performs RAC
maintainance operations, and measures timing intervals in order to ensure clock stability.
3.0 RDRAM Initialization
This stage performs most of the steps needed to initialize the RDRAMs. The rest are performed in stages 5.0,
6.0, and 7.0. All of the steps in 3.0 are carried out through the SIO block interface.
3.1/3.2 SIO Reset
This reset operation is performed before any SIO control register read or write transactions. It clears six
registers (TEST34, CCA, CCB, SKIP, TEST78, and TEST79) and places the INIT register into a special state
(all bits cleared except SKP and SDEVID fields are set to ones).
3.3 Write TEST77 Register
The TEST77 register must be explicitly written with zeros before any other registers are read or written.
3.4 Write TCYCLE Register
The TCYCLE register is written with the cycle time t
units of 64ps. The t
value is determined in stage 1.0.
CYCLE
of the CTM clock (for Channel and RDRAMs) in
CYCLE
3.5 Write SDEVID Register
The SDEVID (serial device identification) register of each RDRAM is written with a unique address value so
that directed SIO read and write transactions can be performed. This address value increases from 0 to 31
according to the distance an RDRAM is from the ASIC component on the SIO bus (the closest RDRAM is
address 0).
Data Sheet M14837EJ3V0DS00
35
PD488448 for Rev. P
µµµµ
3.6 Write DEVID Register
The DEVID (device identification) register of each RDRAM is written with a unique address value so that
directed memory read and write transactions can be performed. This address value increases from 0 to 31.
The DEVID value is not necessarily the same as the SDEVID value. RDRAMs are sorted into regions of the
same core configuration (number of bank, row, and column address bits and core type).
3.7 Write PDNX, PDNXA Registers
The PDNX and PDNXA registers are written with values that are used to measure the timing intervals
connected with an exit from the PDN (powerdown) power state.
3.8 Write NAPX Register
The NAPX register is written with values that are used to measure the timing intervals connected with an exit
from the NAP power state.
3.9 Write TPARM Register
The TPARM register is written with values which determine the time interval between a COL packet with a
memory read command and the Q packet with the read data on the Channel. The values written set each
RDRAM to the minimum value permitted for the system. This will be adjusted later in stage 6.0.
3.10 Write TCDLY1 Register
The TCDLY1 register is written with values which determine the time interval between a COL packet with a
memory read command and the Q packet with the read data on the Channel. The values written set each
RDRAM to the minimum value permitted for the system. This will be adjusted later in stage 6.0.
3.11 Write TFRM Register
The TFRM register is written with a value that is related to the t
parameter for the system. The t
RCD
RCD
parameter is the time interval between a ROW packet with an activate command and the COL packet with a
read or write command.
3.12 SETR/CLRR
First write the following registers with the indicated values:
TEST780004
TEST340040
16
16
Next, each RDRAM is given a SETR command and a CLRR command through the SIO block. This sequence
performs a second reset operation on the RDRAMs. Then the TEST34 and TEST78 registers are rewritten
with zero, in that order.
3.13 Write CCA and CCB Registers
These registers are written with a value halfway between their minimum and maximum values. This shortens
the time needed for the RDRAMs to reach their steady-state current control values in stage 5.0.
3.14 Powerdown Exit
The RDRAMs are in the PDN power state at this point. A broadcast PDNExit command is performed by the
SIO block to place the RDRAMs in the RLX (relax) power state in which they are ready to receive ROW
packets.
3.15 SETF
Each RDRAM is given a SETF command through the SIO block. One of the operations performed by this step
is to generate a value for the AS (autoskip) bit in the SKIP register and fix the RDRAM to a particular read
domain.
36
Data Sheet M14837EJ3V0DS00
488448 for Rev. P
µµµµ
PD
4.0 Controller Configuration
This stage initializes the controller block. Each step of this stage will set a field of the ConfigRMC[63:0] bus to the
appropriate value. Other controller implementations will have similar initialization requirements, and this stage
may be used as a guide.
4.1 Initial Read Data Offset
The ConfigRMC bus is written with a value which determines the time interval between a COL packet with a
memory read command and the Q packet with the read data on the Channel. The value written sets RMC.d1
to the minimum value permitted for the system. This will be adjusted later in stage 6.0.
4.2 Configure Row/Column Timing
This step determines the values of the t
RAS,MIN
, t
RP,MIN
, t
RC,MIN
, t
RCD,MIN
, t
RR,MIN
, and t
RDRAM timing
PP,MIN
parameters that are present in the system. The ConfigRMC bus is written with values that will be compatible
with all RDRAM devices that are present.
4.3 Set Refresh Interval
This step determines the values of the t
RDRAM timing parameter that are present in the system. The
REF,MAX
ConfigRMC bus is written with a value that will be compatible with all RDRAM devices that are present.
4.4 Set Current Control Interval
This step determines the values of the t
CCTRL,MAX
RDRAM timing parameter that are present in the system.
The ConfigRMC bus is written with a value that will be compatible with all RDRAM devices that are present.
4.5 Set Slew Rate Control Interval
This step determines the values of the t
TEMP,MAX
RDRAM timing parameter that are present in the system. The
ConfigRMC bus is written with a value that will be compatible with all RDRAM devices that are present.
4.6 Set Bank/Row/Col Address Bits
This step determines the number of RDRAM bank, row, and column address bits that are present in the
system. It also determines the RDRAM core types (independent, doubled, or split) that are present. The
ConfigRMC bus is written with a value that will be compatible with all RDRAM devices that are present.
5.0 RDRAM Current Control
This step causes the INIT block to generate a sequence of pulses which performs RDRAM maintenance
operations.
6.0 RDRAM Core, Read Domain Initialization
This stage completes the RDRAM initialization
6.1 RDRAM Core Initialization
A sequence of 192 memory refresh transactions is performed in order to place the cores of all RDRAMs into
the proper operating state.
6.2 RDRAM Read Domain Initialization
A memory write and memory read transaction is performed to each RDRAM to determine which read domain
each RDRAM occupies. The programmed delay of each RDRAM is then adjusted so the total RDRAM read
delay (propagation delay plus programmed delay) is constant. The TPARM and TCDLY1 registers of each
RDRAM are rewritten with the appropriate read delay values. The ConfigRMC bus is also rewritten with an
updated value.
Data Sheet M14837EJ3V0DS00
37
PD488448 for Rev. P
µµµµ
7.0 Other RDRAM Register Fields
This stage rewrites the INIT register with the final values of the LSR, NSR, and PSR fields.
In essence, the controller must read all the read-only configuration registers of all RDRAMs (or it must read the
SPD device present on each RIMM), it must process this information, and then it must write all the read-write
registers to place the RDRAMs into the proper operating mode.
Initialization Note :
1. During the initialization process, it is necessary for the controller to perform 128 current control operations
(3xCAL, 1xCAL/SAM) and one temperature calibrate operation (TCEN/TCAL) after reset or after powerdown
(PDN) exit.
2. The behavior of
SPD.
S28IECO=1: Upon powerup, the device enters PDN state. The serial operations SETR, CLRR, and SETF
require a SDEVID match.
See the document detailing the reference initialization procedure for more information on how to handle this in
a system.
3. After the step of equalizing the total read delay of each RDRAM has been completed (i.e. after the TCDLY0
and TCDLY1 fields have been written for the final time), a single final memory read transaction should be
made to each RDRAM in order to ensure that the output pipeline stages have been cleared.
4. The SETF command (in the serial SRQ packet) should only be issued once during the Initialization process,
as should the SETR and CLRR commands.
5. The CLRR command (in the serial SRQ packet) leaves some of the contents of the memory core in an
indeterminate state.
PD488448 Rev. P at initialization is as follows. It is distinguished by the "S28IECO" bit in the
µ
38
Data Sheet M14837EJ3V0DS00
488448 for Rev. P
µµµµ
PD
22. Control Register Summary
Table 22-1 summarizes the RDRAM control registers. Detail is provided for each control register in Figure 22-1.
Read-only bits which are shaded gray are unused and return zero. Read-write bits which are shaded gray are
reserved and should always be written with zero. The RIMM SPD Application Note (DL-0054) of Rambus Inc.
describes additional read-only configuration registers which are present on Direct RIMMs.
The state of the register fields are potentially affected by the IO Reset operation or the SETR/CLRR operation. This
is indicated in the text accompanying each register diagram.
Table 22-1 Control Register Summary (1/2)
SA11..SA0RegisterFi el dread-write/ read-onlyDescription
021
022
023
024
040
041
042
043
044
045
046
16
INITSDEVIDread-write, 6 bitsSerial device ID. Device address for control regi ster read/write.
PSXread-write, 1 bitPower select exit. PDN/NAP exit with device addr on DQA5..0.
SRPread-write, 1 bitSIO repeater. Used to initializ e RDRAM.
NSRread-write, 1 bitNAP self-refresh. Enables self-refresh in NAP mode.
PSRread-write, 1 bitPDN self-ref res h. Enables self-refresh i n P DN m ode.
LSRread-write, 1 bitLow power self-refresh. Enables low power self-refresh.
TENread-write, 1 bitTemperature sensing enable.
TSQread-write, 1 bitTemperature sensing output.
DISread-wri t e, 1 bitRDRAM disable.
16
16
TEST34TEST34read-write, 16 bitsTest regist er.
CNFGAREFBITread-only, 3 bitsRefresh bank bits . Used for multi-bank refresh.
DBLread-only, 1 bitDouble. Specifies doubled-bank architecture.
MVERread-only, 6 bitsManufacturer version. Manufacturer ident i fication number.
PVERread-only, 6 bitsProtocol version. Specifies version of Direct protocol supported.
16
CNFGBBYTread-only, 1 bitByte. Specifies an 8-bit or 9-bit byte siz e.
DEVTYPread-only, 3 bitsDevice type. Device can be RDRAM or some other device c ategory.
SPT
CORG
read-only, 1 bitSplit-core. Eac h core half is an individual dependent c ore.
read-only, 6 bitsCore organization. Bank, row, column address field sizes.
SVERread-only, 6 bitsStepping version. Mask v ersion number.
16
16
16
16
DEVIDDEVIDread-write, 5 bitsDev i ce ID. Device address for memory read/write.
REFBREFBread-writ e, 4 bi tsRefresh bank. Next bank to be refres hed by self-refresh.
REFRREFRread-write, 9 bi t sRefresh row. Next row to be refreshed by REFA , self-refresh.
CCACCAread-write, 7 bitsCurrent control A. Controls IOL output current for DQA.
ASYMAread-write, 1 bitsAsymmetry cont rol. Cont rols as y mmetry of VOL/VOH swing for DQA.
16
CCBCCBread-write, 7 bitsCurrent control B. Controls IOL output current for DQB.
ASYMBread-write, 1 bitsAsymmetry cont rol. Cont rols as y mmetry of VOL/VOH swing for DQB.
16
NAPXNAPXAread-write, 5 bitsNAP exit . Spec if ies length of NAP exit phase A.
NAPXread-wri t e, 5 bitsNAP exit. Specifies length of NAP exit phase A + phase B.
DQSread-wri te, 1 bitDQ select . Selects CMD frami ng f o r NA P/PDN exit.
16
PDNXAPDNXAread-wri te, 13 bitsPDN exit. S pecifies length of P DN exit phase A.
Data Sheet M14837EJ3V0DS00
39
PD488448 for Rev. P
µµµµ
Table 22-1 Control Register Summary (2/2)
SA11..SA0 Regist erFiel dread-wri t e/ read-onlyDescription
047
048
049
04a
04c
04b
16
16
16
16
16
16
PDNXPDNXread-write, 13 bitsPDN exit. Specifi es length of PDN exit phase A + phase B.
TPARM TCASread-wri te, 2 bitst
core parameter. Programmable delay f or read data.
CDLY0-C
core parameter. Determines ROW - COL packet framing interval.
FRM-C
t
core parameter. Programmable delay f or read data.
CDLY-1
datasheet parameter. Speci f i es cycle time in 64ps units.
CYCLE
datasheet parameter.
OFFP
CAC
and t
datasheet parameters.
OFFP
SKIPASread-only, 1 bi tAutoskip val ue established by the SETF c ommand.
MSEread-write, 1 bi tManual skip enable. Allows t he M S value to override the AS val ue.
MSread-write, 1 bitManual skip value.
04d
04e
04f
16
16
16
TEST77 TEST77read-write, 16 bitsTest register. Write wit h zero after SIO reset.
TEST78 TEST78read-write, 16 bitsTest register.
TEST79 TEST79read-write, 16 bitsTest register. Do not read or write after SIO reset.
08016-Off16reserved reservedvendor-specif i cVendor-specific test regi sters. Do not read or write after SIO reset.
40
Data Sheet M14837EJ3V0DS00
Figure 22-1 Control Registers (1/7)
488448 for Rev. P
µµµµ
PD
Control Register : INITAddress : 021
1514131211109876543210
SDE
0
Read/write register.
Reset values are undefined exc ept as affected by SI O Reset as noted below. SETR/ CLRR Reset does not affect t hi s register.
FieldDescription
SDEVID5..0
DIS
TSQ
TEN
LSR
PSR
NSR
SRP
PSX
DISTSQTENLSRPSRNSRSRPPSX0SDEVID4..0
VID5
Serial Device Identif i cation. Compared to SDEVID5..0 serial address field of serial request packet for register
read/write transactions . T hi s determines which RDRAM is selected for the regist er read or wri te operation.
RDRAM disable. DIS=1 causes RDRAM to ignore NAP /PDN exit sequence, DIS=0 permit normal operation.
This mechanism disabl es an RDRAM.
Temperature Sensing Output. TSQ=1 when a temperature trip point has been exc eeded, TSQ=0 when it has
not. TSQ is available during a current control operation (see Figure 25-1).
Temperature Sensing Enable. TEN=1 enabl es temperature sensing circui t ry, permitting the TSQ bit to be
read to determine if a thermal tri p poi nt has been exceeded.
Low Power Self-Refresh. LSR=1 enables longer self-refresh interv al . The self-refresh supply current is
reduced.
PDN Self-Refresh. P S R=1 enabl es self-refresh in PDN m ode. PSR can’t be set whi l e i n P DN mode.
NAP Self-Refresh. NSR=1 enables self-refresh in NAP mode. NSR can’t be se t while in NAP mode.
SIO Repeater. Controls val ue on S IO1; SIO1=SIO0 if SRP =1, SIO1=1 if SRP=0.
Power Exit Select. PDN and NAP are exited with (=0) or without (=1) a device address on the DQA5..0 pins.
PDEV5 (on DQA5) selectes broadc ast (1) or directed (0) exit. For a di rcted exit, PDEV4. .0 (on DQA4..0) is
compared to DEVID4..0 t o select a device.
16
Reset
value
3f
0
0
0
0
0
1
16
Control Register : CNFGAAddress : 023
1514131211109876543210
PVER5..0=000001MVER5..0=mmmmmmDBL1REFBIT2..0=100
Read only register.
FieldDescription
PVER5..0
MVER5..0Manufact urer V ersion. Specifies t he m anufacturer identificat i on num ber.
DBL
REFBIT2..0
Caution In RDRAMs with protoco l version 1 PVER[5:0] =000001, the range of the PDNX field (PDNX[2:0] in the PDNX
Protocol Version. Specifies the Direct P rot ocol version used by this device:
0 – Compliant with version 0. 62.
1 – Compliant with version 0. 7 t hrough this version
2 to 63 – Reserved
Doubled-Bank. DBL=1 means the dev i ce uses a doubled-bank architecture with adjacent-bank dependency. DBL=0
means no dependency.
Refresh Bank Bits. Specifies the number of bank address bits to used by REFA and REFP commands.
Permits multi -bank refresh in future RDRAMs .
register) may not be large enough to specify the location of the restricted interval i n Figure 23-3. In this case,
the effective tS4 parameter must increase and no row or column packets may overlap the restricted i nterval.
See Figure 23-3 and Timing conditions table.
SVER5..0Stepping version. Specifies the mask version number of this dev ice.
CORG4..0
SPTS pl i t -core. SPT=1 means the core i s split, SPT=0 means i t is not.
DEVTYP2..0 Device type. DEVTY P =000 means that this devic e i s an RDRAM.
BYTB yte width. B=1 means the device reads and writes 9-bit mem ory bytes.B=0 means 8 bi t s.
Core organization. This field specifies the number of bank (3, 4, 5, or 6 bits), row (9, 10, 11, or 12 bits), and column (5,
6, or 7 bits) address bits. The enc oding of this field will be specified in a later version of this document.
Control Register : TEST34Address : 022
1514131211109876543210
0000000000000000
Read/write register.
Reset values of TEST34 i s zero (from SIO Reset).
This register are used for tes ting purposes. It must not be read or written after SIO Res et except prior to the SET R/CLRR sequence
when it is written with t he value 0040
After SETR/CLRR it is rewritten to 0000
.
16
.
16
16
16
Control Register : DEVIDAddress : 040
1514131211109876543210
00000000000DEVID4..0
Read/write register.
Reset value is undefined.
FieldDes c ription
DEVID4..0
Device Identification register. DEV I D4..DEVID0 is com pared to DR4..DR0, DC4..DC0, and DX 4. .DX0 fields for all
memory read or write transacti ons. This determines which RDRAM is selected f or t he m emory read or write
transaction.
16
42
Data Sheet M14837EJ3V0DS00
Figure 22-1 Control Registers (3/7)
488448 for Rev. P
µµµµ
PD
Control Register : REFBAddress : 041
1514131211109876543210
00000000000REFB4..0
Read/write register.
FieldDes c ription
REFB4..0
Refresh Bank Register. REFB4. .REFB0 is the bank that will be refres hed nex t during self-refresh. REFB4..0
is incremented after each self-refresh activate and precharge operation pair.
Control Register : REFRAddress : 042
1514131211109876543210
0000000REFR8..0
Read/write register.
FieldDes c ription
REFR8..0
Refresh Row register. REFR8..REFR0 is the row that will be refreshed next by t he RE FA command or by
self-refresh. REFR8.. 0 i s incremented when BR4..0=11111 for t he RE FA command. REFR8..0 is
incremented when REFB4..0=11111 for self-refresh.
Control Register : CCAAddress : 043
1514131211109876543210
00000000
Read/write register.
ASYM
A0
16
16
16
CCA6..0
Reset
value
0
Reset
value
0
FieldDes c ription
ASYMA0
CCA6..0
Control Register : CCBAddress : 044
1514131211109876543210
00000000
Read/write register.
FieldDes c ription
ASYMB0
CCB6..0
ASYMA0 control the asymmetry of the VOL/VOH voltage swing about the V
DQA7..0 pins.
ASYMA0ODF
00.00
10.12
Where ODF is the Over Drive Factor (t he extra I
OL
Current Control A. Controls the I
ASYMB0 control the asymmetry of the VOL/VOH voltage swing about the V
DQB7..0 pins.
ASYMB0ODF
00.00
10.12
Where ODF is the Over Drive Factor (t he extra I
Current Control B. Controls the I
output current for the DQA7..DQA0 pins.
OL
output current for the DQB7..DQB0 pins.
current sunk by an RSL output when ASYMA0 is set).
OL
16
ASYM
B0
current sunk by an RSL output when ASYMB0 is set).
OL
REF
CCB6..0
REF
reference voltage for the
reference voltage for the
Reset
value
0
Reset
value
0
Data Sheet M14837EJ3V0DS00
43
Figure 22-1 Control Registers (4/7)
PD488448 for Rev. P
µµµµ
Control Register : NAPXAddress : 045
1514131211109876543210
00000DQSNAPX4..0NAPXA4..0
16
Read/write register.
Reset value is undefined.
Note t
SCYCLE
is t
CYCLE1
(SCK cycle time).
FieldDescription
DQS
DQ Select. This field specifies the number of SCK cycles (0 ≥ 0.5 cycles, 1 ≥ 1.5 cycles) between the CMD pin
framing sequence and the device selection on DQ5..0. see Fi gure 23-4. This field must be writ ten with a ”1” for this
RDRAM.
NAPX4..0
Nap Exit Phase A plus B. This field specifies the number of SCK cycles during the first plus second phases for exiting
NAP mode. It must s atisfy:
NAPX•t
SCYCLE
≥ NAPXA•t
SCYCLE+tNAPXB,MAX
Do not set this field to zero.
NAPXA4..0
Nap Exit Phase A. This field specifies the number of SCK cycles during the first phase for exiting NAP mode. It must
satisfy:
NAPXA•t
SCYCLE
NAPXA,MAX
≥ t
Do not set this field to zero.
Control Register : PDNXAAddress : 046
1514131211109876543210
00000000000PDNXA4..0
16
Read/write register.
Reset value is undefined.
FieldDes c ription
PDNXA4..0
PDN Exit Phase A. Thi s field specifies the number of (64•SCK cycle) units during the first phase for exiting PDN
mode. It must sat i sfy:
PDNXA•64•t
SCYCLE
PDNXA,MAX
≥ t
Do not set this field to zero.
Note – only PDNXA4..0 are im pl em ented.
SCYCLE
Note – t
Control Register : PDNXAddress : 047
1514131211109876543210
0000000000000PDNX2..0
is t
CYCLE1
(SCK cycle time).
16
Read/write register.
Reset value is undefined.
FieldDes c ription
PDNX2..0
PDN Exit Phase A puls B. This field spec i f i es the number of (256•SCK cycle) units during the first plus second phases
for exiting PDN mode. It must satis fy:
PDNX•256•t
SCYCLE
≥ PDNXA•64•t
SCYCLE+tPDNXB,MAX
It this equation can’t be satisfied, then t he m aximum PDNX value should be wri t ten, and the tS4 / tH4 timing window will
be modified (see Figure 23-4).
Do not set this field to zero.
Note – only PDNX2..0 are impl em ented.
Note – t
SCYCLE
is t
CYCLE1
(SCK cycle time).
44
Data Sheet M14837EJ3V0DS00
Figure 22-1 Control Registers (5/7)
488448 for Rev. P
µµµµ
PD
Control Register : TPARMAddress : 048
1514131211109876543210
000000000TCDLY0TCLSTCAL
16
Read/write register.
Reset value is undefined.
FieldDescription
TCDLY0
Specifies the t
CDLY0-C
core parameter in t
CYCLE
units. This adds a programmabl e del ay to Q (read data) packets,
permitting round trip read delay to al l device to be equalized. This field may be written with t he values “010” (2•t
CYCLE
).
CLS-C
core parameter in t
CAS-C
core parameter in t
CYCLE
units. Should be “10” (2•t
CYCLE
units. This should be “10” (2•t
CYCLE
).
CYCLE
).
TCLS1..0
TCAS1..0
through “101” (5•t
Specifies the t
Specifies the t
The equations relating the core paramet ers to the datasheet parameters f ol l ow:
CAS-C
t
CLS-C
t
CPS-C
t
OFFP=tCPS-C
t
=4•t
RCD=tRCD-C
t
=t
CAC
t
TCDLY0t
0102•t
0113•t
0113•t
0113•t
1004•t
1015•t
=2•t
=2•t
=1•t
=3•t
CYCLE
CYCLE
CYCLE
CYCLE
RCD-C
CYCLE
+ t
+ 1•t
- 1•t
+ t
Not programmable
CAS-C
+ t
CYCLE
– t
CYCLE
CLS-C
+ t
CDLY0-C
CYCLE
CYCLE
CYCLE
CYCLE
CYCLE
CYCLE
CLS-C
CLS-C
CDLY0-C
- 1•t
CYCLE
+ t
CDLY1-C
(see table below programming ranges)
TCDLY1t
0000•t
0000•t
0011•t
0102•t
0102•t
0102•t
CDLY1-C
CYCLE
CYCLE
CYCLE
CYCLE
CYCLE
CYCLE
CAC@tCYCLE
t
7•t
8•t
9•t
10•t
11•t
12•t
=3.30 ns t
CYCLE
CYCLE
CYCLE
CYCLE
CYCLE
CYCLE
CAC@tCYCLE
not allowed
CYCLE
8•t
CYCLE
9•t
CYCLE
10•t
CYCLE
11•t
CYCLE
12•t
CYCLE
=2.50 ns
)
Control Register : TFRMAddress : 049
1514131211109876543210
000000000000TFRM3..0
16
Read/write register.
Reset value is undefined.
FieldDescription
CYCLE
TFRM3..0
Specifies the position of the framing point in t
units. This value must be greater than or equal to the t
parameter. This is the mi ni m um offset between a ROW packet (which places a device at ATTN) and the first COL
packet (directed to that device) which must be fram ed. Thi s field may be written wit h the value “0111” (7•t
through “1010” (10•t
CYCLE
4•t
) that is present in an RDRAM in the memory system. Thus, if an RDRAM with t
present, then TFRM would be programmed to 7•t
CYCLE
). TFRM is usually set to the value which matc hes the lagest t
CYCLE
.
Data Sheet M14837EJ3V0DS00
RCD,MIN
parameter (modulo
RCD,MIN
=11•t
CYCLE
FRM,MIN
CYCLE
were
)
45
Figure 22-1 Control Registers (6/7)
PD488448 for Rev. P
µµµµ
Control Register : TCDLY1Address : 04a
1514131211109876543210
0000000000000TCDLY1
16
Read/write register.
Reset value is undefined.
FieldDescription
TCDLY1
Specifies the value of the t
CDLY1-C
core parameter in t
CYCLE
units. This adds a programmabl e del ay to Q (read data)
packets, permitt i ng round trip read to delay all devices to be equalized. This field may be written with the values “000”
CYCLE
(0•t
) through “010” (2•t
Control Register : SKIPAddress : 04b
1514131211109876543210
000ASMSEMS0000000000
CYCLE
). Refer to TPARM Register for more details.
16
Read/write register (except A S field).
Reset value is zero.
FieldDescription
MS
Manual skip (MS must be 1 when M SE=1). > During initialization, the RDRAMs at the f urthest point in the fif t h read
domain may have selected the AS=0 value, placing t hem at the closest point in a s i xth read domain. Setting t he
MSE/MS fields t o 1/1 overrides the autoskip value and returns hem to 111 he furthest point of the fifth read dom ai n.
MSE
AS
Manual skip enable (0=auto, 1=manual ).
Autoskip. Read-only v al ue determined by autoskip circuit and stored when SETF serial c ommand is received by
RDRAM during initializat i on. In Figure34-1, AS=1 corresponds t o the early Q(a1) packet and AS=0 t o t he Q(a1) packet
CYCLE
one t
later for the four uncertain c ases.
Control Register : TCYCLEAddress : 04c
1514131211109876543210
00TCYCLE13..0
16
Read/write register.
Reset value is undefined.
FieldDescription
TCYCLE13..0
Specifies the value of the t
CYCLE
should be written with the “00027
datasheet parameter in 64ps units. For the t
16
” (39•64ps).
CYCLE,MIN
of 2.50 ns (2500ps), this field
46
Data Sheet M14837EJ3V0DS00
Figure 22-1 Control Registers (7/7)
488448 for Rev. P
µµµµ
PD
Control Register : TEST77Address : 04d
Control Register : TEST78Address : 04e
Control Register : TEST79Address : 04f
1514131211109876543210
0000000000000000
Read/write register.
These registers must onl y be used for testing purposes.
FieldDescription
•
TEST77
TEST78
TEST79
It must be written with zero after SIO reset. These registers must only be used for testing purposes
except prior to the SETR/CLRR sequence when TEST78 is written with the value 0004
SETR/CLRR it is rewritten to 0000
Do not read or written after SIO res et.0
Do not read or written after SIO res et.0
.
16
16
16
16
. After
16
Reset
value
Data Sheet M14837EJ3V0DS00
47
PD488448 for Rev. P
µµµµ
23. Power State Management
Table 23-1 summarizes the power states available to a Direct RDRAM. In general, the lowest power states have
the longest operational latencies. For example, the relative power levels of PDN state and STBY state have a ratio of
about 1:110, and the relative access latencies to get read data have a ratio of about 250:1.
PDN state is the lowest power state available. The information in the RDRAM core is usually maintained with selfrefresh; an internal timer automatically refreshes all rows of all banks. PDN has a relatively long exit latency because
the TCLK/RCLK block must resynchronize itself to the external clock signal.
NAP state is another low-power state in which either self-refresh or REFA-refresh are used to maintain the core.
See
24. Refresh
the TCLK/RCLK block maintains its synchronization state relative to the external clock signal at the time of NAP
entry. This imposes a limit (t
or ATTN to update this synchronization state.
Power State DescriptionBlocks consuming power Power state DescriptionBlocks consuming power
PDNPowerdown state.Self-refreshNAPNap state. Similar to
STBYStandby s tate.
ATTNRAttention read state.
for a description of the two refresh mechanisms. NAP has a shorter exit latency than PDN because
) on how long an RDRAM may remain in NAP state before briefly returning to STBY
NLIMIT
Table 23-1 Power State Summary
Self-refresh or
REFA-refresh
TCLK/RCLK-Nap
REFA-refresh
TCLK/RCLK
ROW demux receiver
COL demux receiver
REFA-refresh
TCLK/RCLK
ROW demux receiver
COL demux receiver
DQ demux receiver
Core power
Ready for ROW
packets.
Ready for ROW and
COL packets.
Sending Q (read data)
packets.
REFA-refresh
TCLK/RCLK
ROW demux receiver
REFA-refresh
TCLK/RCLK
ROW demux receiver
COL demux receiver
DQ mux transmitter
Core power
PDN except lower
wake-up latency.
ATTNAttention s t ate.
Ready for ROW and
COL packets.
ATTNWAt tention write state.
Ready for ROW and
COL packets.
Ready for D (write data)
packets.
48
Data Sheet M14837EJ3V0DS00
488448 for Rev. P
µµµµ
PD
Figure 23-1 summarizes the transition conditions needed for moving between the various power states. Note that
NAP and PDN have been divided into two substates (NAP-A/NAP-S and PDN-A/PDN-S) to account for the fact that a
NAP or PDN exit may be made to either ATTN or STBY states.
Figure 23-1 Power State Transition Diagram
automatic
ATTNRATTNW
automatic
automatic
automatic
automatic
automatic
ATTN
NLIMIT
t
RLX
NAPR • RLXR
PDEV.CMD•SIO0
NAPR • RLXR
PDEV.CMD•SIO0
NAP-A
NAP
NAP-S
ATTN
PDNR
STBY
NAPR
PDNR • RLXR
PDEV.CMD•SIO0
PDNR • RLXR
PDEV.CMD•SIO0
PDN-A
PDN
PDN-S
SETR/CLRR
Notation:
SETR/CLRR - SETR/CLRR Reset sequence in SRQ packet
PDNR - PDNR command in ROWR packet
NAPR - NAPR command in ROWR packet
RLXR - RLX command in ROWR packet
RLX - RLX command in ROWR,COLC,COLX packets
SIO0 - SIO0 input value
PDEV.CMD - (PDEV=DEVID)•(CMD=01)
ATTN - ROWA packet(non-broadcast) or ROWR packet
(non-broadcast) with ATTN command
At initialization, the SETR/CLRR Reset sequence will put the RDRAM into PDN-S state. The PDN exit sequence
involves an optional PDEV specification and bits on the CMD and SIO
IN
pins.
Once the RDRAM is in STBY, it will move to the ATTN/ATTNR/ATTNW states when it receives a non-broadcast
ROWA packet or non-broadcast ROWR packet with the ATTN command. The RDRAM returns to STBY from these
three states when it receives a RLX command. Alternatively, it may enter NAP or PDN state from ATTN or STBY
states with a NAPR or PDNR command in an ROWR packet. The PDN or NAP exit sequence involves an optional
PDEV specification and bits on the CMD and SIO0 pins. The RDRAM returns to the ATTN or STBY sta t e it was
originally in when it first entered NAP or PDN.
An RDRAM may only remain in NAP state for a time t
. It must periodically return to ATTN or STBY.
NLIMIT
The NAPRC command causes a napdown operation if the RDRAM’s NCBIT is set. The NCBIT is not directly visible.
It is undefined on reset. It is set by a NAPR command to the RDRAM, and it is cleared by an ACT command to the
RDRAM. It permits a controller to manage a set of RDRAMs in a mixture of power states.
STBY state is the normal idle state of the RDRAM. In this state all banks and sense amps have usually been left
precharged and ROWA and ROWR packets on the ROW pins are being monitored. When a non-broadcast ROWA
packet or non-broadcast ROWR packet(with the ATTN command) packet addressed to the RDRAM is seen, the
RDRAM enters ATTN state (see the right side of Figure 23-2). This requires a time t
activates the specified row of the specified bank. A time TFRM•t
to frame COL packets (TFRM is a control register field – see Figure 22-1(5/7) “
after the ROW packet, the RDRAM will be able
CYCLE
TFRM Register
during which the RDRAM
SA
”). Once in ATTN
state, the RDRAM will automatically transition to the ATTNW and ATTNR states as it receives WR and RD
commands.
Data Sheet M14837EJ3V0DS00
49
PD488448 for Rev. P
µµµµ
Once the RDRAM is in ATTN, ATTNW, or ATTNR states, it will remain there until it is explicitly returned to the STBY
state with a RLX command. A RLX command may be given in an ROWR, COLC, or COLX packet (see the left side
of Figure 23-2). It is usually given after all banks of the RDRAM have been precharged; if other banks are still
activated, then the RLX command would probably not be given.
If a broadcast ROWA packet or ROWR packet (with the ATTN command) is received, the RDRAM’s power state
doesn’t change. If a broadcast ROWR packet with RLXR command is received, the RDRAM goes to STBY.
Figure 23-2 STBY Entry (left) and STBY Exit (right)
CTM/CFM
ROW2
..ROW0
COL4
..COL0
DQA7..0
DQB7..0
Power
State
T
T
T
T
T
1
2
3
0
RLXR
RLXC
RLXX
ATTN
T
T
T
T
5
6
7
4
t
AS
T
T
8
9
T
10
STBY
T
T
T
T
11
15
12
T
13
14
CTM/CFM
..ROW0
COL4
..COL0
DQA7..0
Power
T
T
T
17
18
19
16
ROW2
DQB7..0
State
T
T
T
T
T
21
22
20
T
23
0
T
1
2
ROP a0
t
STBY
T
SA
T
3
T
T
T
T
5
6
7
4
COP a1
XOP a1
TFRM•t
T
T
9
8
COP a1
COP a1
CYCLE
T
T
10
11
COP a1
COP a0
XOP a0
ATTN
T
T
T
T
13
14
15
12
16
ROP=non-broadcast
ROWA or ROWR/ATTN
a0={d0, b0, r0}
a1={d1, b1, c1}
No COL packets may be
placed in the three
indicated positions; i.e. at
(TFRM-{1,2,3})•t
A COL packet to device d0
(or any other device) is okay at
CYCLE
(TFRM)•t
or later.
A COL packet to another device
(d1!=d0) is okay at
CYCLE
(TFRM-4)•t
or earlier.
CYCLE
.
Figure 23-3 shows the NAP entry sequence (left). NAP state is entered by sending a NAPR command in a ROW
packet. A time t
clock on CTM/CFM must remain stable for a time t
is required to enter NAP state (this specification is provided for power calculation purposes). The
ASN
after the NAPR command.
CD
Figure 23-3 NAP Entry (left) and PDN Entry (right)
T
CTM/CFM
ROW2
..ROW0
COL4
..COL0
DQA7..0
DQB7..0
Power
State
Note The(eventual) NAP/PDN exit will be to the same ATTN/STBY state the RDRAM was in prior to NAP/PDN entry
T
T
T
T
1
2
3
0
ROP a0
(NAPR)
4
COP a0
XOP a0
ATTN/STBY
T
T
5
6
restricted
t
NPQ
restricted
t
ASN
T
T
7
t
Note
8
CD
T
T
9
10
ROP a1
COP a1
XOP a1
T
T
T
T
T
11
15
12
T
13
14
T
T
T
T
17
18
19
16
CTM/CFM
ROW2
..ROW0
COL4
..COL0
T
T
T
T
21
22
20
T
23
0
T
1
2
ROP a0
(PDNR)
COP a0
XOP a0
T
3
T
4
T
T
5
6
restricted
t
NPQ
restricted
T
T
7
8
t
CD
T
T
9
10
ROP a1
T
T
T
T
13
14
11
12
a0={d0, b0, r0, c0}
a1={d1, b1, c1, c1}
No ROW or COL packets directed
to device d0 may overlap the
restricted interval. No broadcast
ROW packets may overlap
the quiet interval.
COP a1
XOP a1
ROW or COL packets to a device
other than d0 may overlap the
restricted interval.
DQA7..0
NAP
DQB7..0
Power
State
t
ASP
ATTN/STBY
Note
ROW or COL packets directed
to device d0 after the restricted
interval will be ignored.
PDN
The RDRAM may be in ATTN or STBY state when the NAPR command is issued. When NAP state is exited, the
RDRAM will return to the original starting state (ATTN or STBY). If it is in ATTN state and a RLXR command is
specified with NAPR, then the RDRAM will return to STBY state when NAP is exited.
Figure 23-3 also shows the PDN entry sequence (right). PDN state is entered by sending a PDNR command in a
ROW packet. A time t
purposes). The clock on CTM/CFM must remain stable for a time t
50
is required to enter PDN state (this specification is provided for power calculation
ASP
after the PDNR command.
CD
Data Sheet M14837EJ3V0DS00
488448 for Rev. P
µµµµ
PD
The RDRAM may be in ATTN or STBY state when the PDNR command is issued. When PDN state is exited, the
RDRAM will return to the original starting state (ATTN or STBY). If it is in ATTN state and a RLXR command is
specified with PDNR, then the RDRAM will return to STBY state when PDN is exited. The current- and slew-ratecontrol levels are re-established.
The RDRAM’s write buffer must be retired with the appropriate COP command before NAP or PDN are entered.
Also, all the RDRAM’s banks must be precharged before NAP or PDN are entered. The exception to this is if NAP is
entered with the NSR bit of the INIT register cleared(disabling self-refresh in NAP). The commands for relaxing,
retiring, and precharging may be given to the RDRAM as late as the ROPa0, COPa0, and XOPa0 packets in Figure
23-3. No broadcast packets nor packets directed to the RDRAM entering NAP or PDN may overlay the quiet window.
This window extends for a time t
after the packet with the NAPR or PDNR command.
NPQ
Figure 23-4 shows the NAP and PDN exit sequences. These sequences are virtually identical; the minor
differences will be highlighted in the following description.
Before NAP or PDN exit, the CTM/CFM clock must be stable for a time tCE. Then, on a falling and rising edge of
SCK, if there is a “01” on the CMD input, NAP or PDN state will be exited. Also, on the falling SCK edge the SIO0
input must be at a 0 for NAP exit and 1 for PDN exit.
If the PSX bit of the INIT register is 0, then a device PDEV5..0 is specified for NAP or PDN exit on the DQA5..0 pins.
This value is driven on the rising SCK edge 0.5 or 1.5 SCK cycles after the original falling edge, depending upon the
value of the DQS bit of the NAPX register. If the PSX bit of the INIT register is 1, then the RDRAM ignores the
PDEV5..0 address packet and exits NAP or PDN when the wake-up sequence is presented on the CMD wire. The
ROW and COL pins must be quiet at a time t
t
around the indicated falling SCK edge(timed with the PDNX or
S4
H4
/
NAPX register fields). After that, ROW and COL packets may be directed to the RDRAM which is now in ATTN or
STBY state.
Figure 23-5 shows the constraints for entering and exiting NAP and PDN states. On the left side, an RDRAM exits
NAP state at the end of cycle T3. This RDRAM may not re-enter NAP or PDN state for an interval of t
enters NAP state at the end of cycle T13. This RDRAM may not re-exit NAP state for an interval of t
. The RDRAM
NU0
. The equations
NU1
for these two parameters depend upon a number of factors, and are shown at the bottom of the figure. NAPX is the
value in the NAPX field in the NAPX register.
On the right side of Figure23-4, an RDRAM exits PDN state at the end of cycle T3. This RDRAM may not re-enter
PDN or NAP state for an interval of t
re-exit PDN state for an interval of t
. The RDRAM enters PDN state at the end of cycle T13. This RDRAM may not
PU0
. The equations for these two parameters depend upon a number of factors,
PU1
and are shown at the bottom of the figure. PDNX is the value in the PDNX field in the PDNX register.
Data Sheet M14837EJ3V0DS00
51
Figure 23-4 NAP and PDN Exit
PD488448 for Rev. P
µµµµ
T
T
T
1
0
T
T
2
T
T
3
T
5
6
7
4
CTM/CFM
ROW2
..ROW0
If PSX=1 in Init register,
then NAP/PDN exit is
broadcast (no PDEV field).
COL4
..COL0
DQA7..0
DQB7..0
tS3t
H3
Note 2
PDEV5..0
t
CE
DQS=0
SCK
CMD
SIO0
The packet is repeated
from SIO0 to SIO1
SIO1
Power
State
Notes 1. Use 0 for NAP exit, 1 for PDN exit
2. Device selection timing slot is selected by DQS field of NAPX register
3. The DQS field must be written with “1” for this RDRAM.
4. Exit to STBY or ATTN depends upon whether RLXR was asserted at NAP or PDN entry time
0 1
Note 1
0/1
Note 1
0/1
NAP/PDN
DQS=0
T
8
T
T
9
10
tS3t
Note 2
PDEV5..0
Note 2,3
Note 2
T
T
T
T
11
T
12
16
T
13
14
15
T
T
T
T
17
18
19
20
T
T
T
T
21
22
23
T
T
25
24
T
T
26
T
T
27
T
29
30
31
28
No ROW packets may overlap
the restricted interval
No COL packets may overlap
the restricted interval if device
H3
DQS=1
PDEV is exiting the NAP-A or
PDN-A states
Note 2
Effective hold becomes
tH4’ = tH4 +[PDNXA•64•tSCYCLE + tPDNXB,MAX] - [PDNX•256•tSCYCLE]
if [PDNX•256•tSCYCLE] < [PDNXA•64•tSCYCLE + tPDNXB,MAX].
DQS=1
(NAPX•t )/(256•PDNX•t )
SCYCLE
STBY/ATTN
Note 2
SCYCLE
Note 4
T
32
T
T
T
T
33
34
35
36
ROP
COP
XOP
T
37
T
T
38
T
T
39
40
restricted
t
S4tH4
restricted
t
S4tH4
T
T
T
41
42
T
T
43
T
45
46
47
44
ROP
COP
XOP
Figure 23-5 NAP Entry/Exit Windows (left) and PDN Entry/Exit Windows (right)
T
T
T
0
T
T
1
T
T
2
T
5
6
3
7
4
CTM/CFM
ROW2
..ROW0
SCK
NAP exit
CMD
t =5•t +(2+NAPX)•t
NU0
t =8•t - (0.5•t )
NU1
=23•t
CYCLE
CYCLE
CYCLE
0 1
no entry to NAP or PDN
SCYCLE
T
8
t
NU0
T
T
9
10
SCYCLE
T
T
11
T
T
13
12
NAP entry
NAPR
no exit
T
T
T
14
15
17
16
t
NU1
if NSR=0
if NSR=1
T
18
T
T
19
0 1
T
T
T
T
21
22
23
20
T
T
24
T
T
25
T
T
26
T
T
T
1
2
27
3
0
4
CTM/CFM
ROW2
..ROW0
SCK
PDN exit
CMD
t =5•t +(2+256•PDNX)•t
PU0
t =8•t - (0.5•t )
PU1
=23•t
CYCLE
CYCLE
CYCLE
0 1
no entry to NAP or PDN
T
5
6
T
T
T
9
7
8
t
PU0
SCYCLE
T
10
T
T
11
SCYCLE
T
T
13
14
12
PDN entry
PDNR
t
no exit
if PSR=0
if PSR=1
T
15
PU1
T
T
T
T
17
18
19
16
0
52
Data Sheet M14837EJ3V0DS00
488448 for Rev. P
µµµµ
PD
24. Refresh
RDRAMs, like any other DRAM technology, use volatile storage cells which must be periodically refreshed. This is
accomplished with the REFA command. Figure 24-1 shows an example of this.
The REFA command in the transaction is typically a broadcast command (DR4T and DR4F are both set in the
ROWR packet), so that in all devices bank number Ba is activated with row number REFR, where REFR is a control
register in the RDRAM. When the command is broadcast and ATTN is set, the power state of the RDRAMs (ATTN or
STBY) will remain unchanged. The controller increments the bank address Ba for the next REFA command. When
Ba is equal to its maximum value, the RDRAM automatically increments REFR for the next REFA command.
On average, these REFA commands are sent once every t
bits and RBIT are the number of row address bits) so that each row of each bank is refreshed once every t
interval.
The REFA command is equivalent to an ACT command, in terms of the way that it interacts with other packets (see
Table 6-1). In the example, an ACT command is sent after t
REFA command.
A second ACT command can be sent after a time t
to address c0, the same bank (or an adjacent bank) as the
RC
REFA command.
Note that a broadcast REFP command is issued a time t
RAS
the refreshed bank in all RDRAMs. After a bank is given a REFA command, no other core operations(activate or
precharge) should be issued to it until it receives a REFP.
It is also possible to interleave refresh transactions (not shown). In the figure, the ACT b0 command would be
replaced by a REFA b0 command. The b0 address would be broadcast to all devices, and would be {Broadcast,
Ba+2,REFR}. Note that the bank address should skip by two to avoid adjacent bank interference. A possible bank
incrementing pattern would be: {12, 10, 5, 3, 0, 14, 9, 7, 4, 2, 13, 11, 8, 6, 1, 15, 28, 26, 21, 19, 16, 30, 25, 23, 20, 18,
•
29, 27, 24, 22, 17, 31}. Every time bank 31 is reached, a REFA command would increment the REFR register.
A second refresh mechanism is available for use in PDN and NAP power states. This mechanism is called selfrefresh mode. When the PDN power state is entered, or when NAP power state is entered with the NSR control
register bit set, then self-refresh is automatically started for the RDRAM.
Self-refresh uses an internal time base reference in the RDRAM. This causes an activate and precharge to be
carried out once in every t
REF /
BBIT+RBIT
2
interval. The REFB and REFR control registers are used to keep track of the
bank and row being refreshed.
Before a controller places an RDRAM into self-refresh mode, it should perform REFA/REFP refreshes until the bank
address is equal to the maximum value. This ensures that no rows are skipped. Likewise, when a controller returns
an RDRAM to REFA/REFP refresh, it should start with the minimum bank address value (zero).
Figure 24-2 illustrates the requirement imposed by the t
BURST
enabled) power states are exited, the controller must refresh all banks of the RDRAM once during the interval t
after the restricted interval on the ROW and COL buses. This will ensure that regardless of the state of self-refresh
during PDN or NAP, the t
parameter is met for all banks. During the t
REF, MAX
refreshed in a single burst, or they may be scattered throughout the interval. Note that the first and last banks to be
refreshed in the t
interval are numbers 12 and 31, in order to match the example refresh sequence.
BURST
BBIT+RBIT
2
REF /
to address b0, a different (non-adjacent) bank than the
RR
after the initial REFA command in order to precharge
(where BBIT are the number of bank address
parameter. After PDN or NAP (when self-refresh is
interval, the banks may be
BURST
REF
BURST
Data Sheet M14837EJ3V0DS00
53
Figure 24-1 REFA/REFP Refresh Transaction Example
PD488448 for Rev. P
µµµµ
CTM/CFM
ROW2
..ROW0
COL4
..COL0
DQA7..0
DQB7..0
CTM/CFM
ROW2
..ROW0
COL4
..COL0
DQA7..0
DQB7..0
T
Transaction a: REFAa0 = {Broadcast,Ba,REFR}
T
T
T
T
1
2
3
0
4
REFA a0ACT c0
T
T
T
T
5
6
7
t
RR
T
T
9
8
ACT b0
T
T
T
T
10
11
T
12
16
T
13
14
15
T
T
T
T
17
18
19
20
t
RC
T
T
T
T
21
22
23
T
T
25
24
T
T
26
T
T
27
T
T
29
28
T
30
31
33
32
REFP a1
t
RAS
t
REF
BBIT+RBIT
/2
t
RP
a1 = {Broadcast,Ba}
Transaction b: xx b0 = {Db, /={Ba,Ba+1,Ba-1}, Rb}
Transaction c: xx c0 = {Dc, ==Ba, Rc}
2. Device selection timing slot is selected by DQS field of NAPX register
0 1
Note 1
0/1
Note 1
0/1
NAP/PDN
DQS=0
Note 2
DQS=1
Note 2
(NAPX•t )/(256•PDNX•t )
SCYCLE
SCYCLE
STBY
54
Data Sheet M14837EJ3V0DS00
488448 for Rev. P
L
µµµµ
PD
25. Current and Temperature Control
Figure 25-1 shows an example of a transaction which performs current control calibration. It is necessary to
perform this operation once to every RDRAM in every t
proper range.
This example uses four COLX packets with a CAL command. These cause the RDRAM to drive four calibration
packets Q(a0) a time t
later. An offset of t
CAC
must be placed between the Q(a0) packet and read data Q(a1)
RDTOCC
from the same device. These calibration packets are driven on the DQA4..3 and DQB4..3 wires. The TSQ bit of the
INIT register is driven on the DQA5 wire during same interval as the calibration packets. The remaining DQA and
DQB wires are not used during these calibration packets. The last COLX packet also contains a SAM command
(concatenated with the CAL command). The RDRAM samples the last calibration packet and adjusts its IOL current
value.
Unlike REF commands, CAL and SAM commands cannot be broadcast. This is because the calibration packets
from different devices would interfere. Therefore, a current control transaction must be sent every t
is the number of RDRAMs on the Channel. The device field Da of the address a0 in the CAL/SAM command should
be incremented after each transaction.
Figure 25-2 shows an example of a temperature calibration sequence to the RDRAM. This sequence is broadcast
once every t
interval to all the RDRAMs on the Channel. The TCEN and TCAL are ROP commands, and cause
TEMP
the slew rate of the output drivers to adjust for temperature drift. During the quiet interval t
calibrated can’t be read, but they can be written.
interval in order to keep the IOL output current in its
CCTRL
CCTRL
the devices being
TCQUIET
/N, where N
CTM/CFM
ROW2
..ROW0
COL4
..COL0
DQA7..0
DQB7..0
CTM/CFM
ROW2
..ROW0
COL4
..COL0
DQA7..0
DQB7..0
Figure 25-1 Current Control CAL/SAM Transaction Example
T
Q (a1)
T
T
T
T
1
2
3
0
Read data from the same
device from an earlier RD
command must be at this
packet position or earier.
CAL a0CAL a2
t
READTOCC
Transaction a0: CAL/SAM
Transaction a1: RD
Transaction a2: CAL/SAM
T
T
T
T
5
6
7
4
CAL a0CAL a0CAL/SAM a0
t
CAC
T
T
8
T
T
T
9
13
10
11
12
Q (a0)
T
T
T
14
15
Read data from a different
device from an earlier RD
command can be anywhere
prior to the Q(a0) packet.
T
T
T
T
17
18
19
16
20
a0 = {Da, Bx}
a1 = {Da, Bx}
a2 = {Da, Bx}
T
T
T
T
21
22
23
t
CCTRL
T
T
T
T
25
26
27
24
28
Read data from a different
device from a later RD
command can be anywhere
after to the Q(a0) packet.
T
T
T
29
30
31
T
t
T
T
33
32
T
T
T
34
35
36
CCSAMTOREAD
T
T
T
37
Read data from the same
device from a later RD
command must be at this
packet position or later.
T
T
41
38
42
39
40
Q (a1)
DQA5 of the first calibrate packet has the inverted TSQ bit of INIT
control register; i.e. logic 0 or high voltage means hot temperature.
When used for monitoring, it should be enabled with the DQA3
bit (current control one value) in case there is no RDRAM present:
HotTemp = /DQA5
•
DQA3
Note that DQB3 could be used instead of DQA3.
Figure 25-2 Temperature Calibration (TCEN-TCAL) Transactions to RDRAM
T
T
T
1
0
T
T
T
5
2
3
4
TCEN
Any ROW packet may be
placed in the gap between the
ROW packets with the
TCEN and TCAL commands.
T
T
6
t
T
7
8
TCEN
T
9
TCAL
T
T
T
T
T
10
11
12
t
TCAL
T
T
13
14
15
T
T
17
16
T
T
T
21
18
19
20
t
TCQUIET
No read data from devices
being calibrated
T
22
T
23
t
TEMP
T
T
T
24
T
T
25
T
T
26
T
27
31
28
T
29
30
T
T
T
T
33
34
35
32
T
T
37
36
T
T
T
41
38
39
40
T
T
T
T
T
T
45
46
43
42
47
44
T
T
T
T
T
45
46
43
47
44
TCEN
CA
Data Sheet M14837EJ3V0DS00
55
PD488448 for Rev. P
µµµµ
26. Electrical Conditions
Electrical Conditions
SymbolParameter and ConditionsMIN.MAX.Unit
TjJunction temperature under bias
V
DD, VDDa
VDD,N,V
VDD,N,V
V
CMOS
DDa,N
DDa,N
Supply voltage2.50 – 0.132.50 + 0.13V
Supply voltage droop (DC) during NAP i nt erval (t
Supply voltage ripple (AC) during NAP interval (t
Supply voltage for CMOS pi ns (2.5V controllers)2.50 – 0.132.50 + 0.25V
Supply voltage for CMOS pi ns (1.8V controllers)1.80 – 0.11.80 + 0.2V
V
TERM
V
REF
V
DIL
V
DIH
V
DIS
A
DI
V
X
V
CM
V
CIS, CTM
V
CIS, CFM
V
IL, CMOS
V
IH, CMOS
Termination voltage1.80 – 0.11.80 + 0.1V
Reference voltage1.40 – 0.21.40 + 0.2V
RSL data input - low voltageV
RSL data input - high voltageV
RSL data input swing : V
RSL data asymmetry : A
DIS
DI
= V
= [(V
RSL clock input - cros sing point of true and complement signals1.31.8V
RSL clock input - common mode VCM = (V
RSL clock input swing : V
RSL clock input swing : V
CIS
CIS
= V
= V
CMOS input low voltage– 0.3+ (V
CMOS input high voltageV
DIH
DIH
CIH
CIH
)—2.0%
NLIMT
)–2.0+2.0%
NLIMT
0.5V
REF –
0.2V
REF +
– V
DIL
– V
) + (V
– V
REF
– V
– V
DIL
+ V
CIH
(CTM, CTMN pins).0.350.70V
CIL
(CFM, CFMN pins).0.1250.70V
CIL
)] / V
REF
DIS
) / 21.41.7V
CIL
0.41.0V
0–20%
/ 2+0.25V
CMOS
100
0.2V
REF –
0.5V
REF +
/ 2– 0.25)V
CMOS
0.3V
CMOS +
C
°
56
Data Sheet M14837EJ3V0DS00
488448 for Rev. P
µµµµ
PD
27. Timing Conditions
Timing Conditions
SymbolParameterMIN.MAX.UnitFigures
t
CYCLE
tCR, t
CF
tCH, t
CL
t
TR
t
DCW
tDR, t
DF
tS, t
H
t
, t
DR1
t
DR2, tDF2
t
CYCLE1
t
, t
CH1
t
S1
t
H1
t
S2
t
H2
t
S3
t
H3
t
S4
t
H4
V
IL, CMOS
V
IH, CMOS
t
NPQ
t
READTOCC
t
CCSAMTOREAD
t
CE
t
CD
t
FRM
t
NLIMIT
t
REF
t
CCTRL
t
TEMP
t
TCEN
t
TCAL
t
TCQUIET
t
PAUSE
t
BURST
CTM and CFM cycle times-C603.333.83ns
-C712.813.83
-C802.503.83
CTM and CFM input rise and fall ti m es0.20.5ns
CTM and CFM high and low times40%60%t
CTM-CFM differential(MSE/MS=0/0)0.01.0t
CMD,SCK input rise and f all times—2.0ns
SCK cycle time - Serial control register transactions1,000—ns
SCK cycle time - Power transitions10—ns
SCK high and low times4.25—ns
CL1
CMD setup time to SCK rising or falling edge
CMD hold time to SCK risi ng or falling edge
Note5
Note5
1.25—ns
1—ns
SIO0 setup time to SCK fal l i ng edge40—ns
SIO0 hold time to SCK falli ng edge40—ns
PDEV setup time on DQA5. .0 to SCK rising edge0—ns
PDEV hold time on DQA5.. 0 t o SCK rising edge5.5—ns
ROW2..0, COL4..0 setup ti m e for quiet window
Note6
–1—t
ROW2..0, COL4..0 hold time for quiet window5—t
CMOS input low voltage - over / undershoot voltage
–0.7+(V
duration is less than or equal t o 5 ns
CMOS input high voltage - over / undershoot voltage
V
/2 + 0.6V
CMOS
duration is less than or equal t o 5ns
Quiet on ROW / COL bits during NAP / PDN entry4—t
Offset between read data and CC pack et s (same device)12—t
Offset between CC packet and read dat a (same device)8—t
CTM/CFM stable before NAP/PDN exit2—t
CTM/CFM stable after NAP/PDN entry100—t
ROW packet to COL packet A TTN f ram i ng del ay7—t
Maximum time in NAP mode—10
Refresh interval—32ms
Current control interval34 t
CYCLE
Temperature control interval—100ms
TCE command to TCAL command150—t
TCAL command to quiet window22t
Quiet window (no read data)140—t
RDRAM delay (no RSL operations allowed)—200
Interval after PDN or NAP (with self-refresh) exit in which
—200
all banks of the RDRAM mus t be refreshed at least once.
MSE/MS are fields of the SKIP register. For this combination (skip override) the t
effectively 0.0 to 0.0.
2.
This parameter also applies to a -C80 or -C71 part when operated with t
3.
This parameter also applies to a -C80 part when operated with t
S,MIN
4.
t
specified t
5.
With V
6.
Effective hold becomes t
if [PDNX • 256 • t
and t
IL,CMOS
H,MIN
CYCLE
= 0.5 V
for other t
values.
CMOS
SCYCLE
CYCLE
values can be interpolated between or extrapolated from the timings at the 3
− 0.6 V and V
H4
’=tH4 + [PDNXA • 64 • t
IH,CMOS
] < [PDNXA • 64 • t
= 0.5 V
SCYCLE
SCYCLE
PDNXB,MAX
+ t
CMOS
+ t
+ 0.6 V
PDNXB,MAX
]. See
CYCLE
CYCLE
= 2.81ns.
] − [PDNX • 256 • t
Figure 23-4
DCW
parameter range is
= 3.33 ns.
.
SCYCLE
]
58
Data Sheet M14837EJ3V0DS00
488448 for Rev. P
µµµµ
PD
28. Electrical Characteristics
Electrical Characteristics
SymbolParameter and ConditionsMIN.M AX.Unit
JC
Θ
I
REF
I
OH
I
ALL
I
OL
∆
r
OUT
I
I,CMOS
V
OL,CMOS
V
OH,CMOS
This measurement is made in manual current control mode; i.e. with all output device legs sinking current.
Note
Junction-to-Case thermal resistance—0.5
V
current @ V
REF
REF,MAX
RSL output high current @ (0≤V
RSL IOL current @ VOL=0.9 V, V
OUT
DD,MIN
V
)–10+10
DD
≤
Note
, T
j,MAX
–10+10
3090mA
RSL IOL current resolution step—2.0mA
Dynamic output impedance150—
CMOS input leakage current @ (0
CMOS output low voltage @ I
CMOS output high voltage @ I
V
I,CMOS
≤
= 1.0 mA—0.3V
OL,CMOS
OH,CMOS = –
0.25 mAV
)–10.0+10.0
VCMOS
≤
CMOS –
0.3—V
C/Watt
°
29. Timing Characteristics
A
µ
A
µ
Ω
A
µ
Timing Characteristics
SymbolParameterMIN.MAX.UnitFigure(s)
t
Q
tQR, t
QF
t
Q1
t
HR
t
, t
QR1
QF1
t
PROP1
t
NAPXA
t
NAPXB
t
PDNXA
t
PDNXB
t
AS
t
SA
t
ASN
t
ASP
Notes 1
Note3
CTM-to-DQA/DQB output timet
CYCLE
t
CYCLE
t
CYCLE
= 2.50 ns
= 2.81 ns
= 3.33 ns
–0.260
–0.300
–0.350
Note2,3
Note1,3
DQA/DQB output rise and fall times0.20.45ns
SCK-to-SIO0 delay @ C
SCK(pos)-to-SIO0 delay @ C
SIO
rise/fall @ C
OUT
LOAD,MAX =
SIO0-to-SIO1 or SIO1-to-SIO0 delay @ C
= 20 pF (SD read packet)—10ns
LOAD,MAX
= 20pF (SD read data hold)2—ns
LOAD,MAX
20 pF—5ns
LOAD,MAX =
20 pF—10ns
NAP exit delay - phase A—50ns
NAP exit delay - phase B—40ns
PDN exit delay - phase A—4
PDN exit delay - phase B—9,000t
ATTN-to-STBY power state del ay—1t
STBY-to-ATTN power state del ay—0t
ATTN/STBY-to-NAP power s t ate delay—8t
ATTN/STBY-to-PDN power st ate delay—8t
. This parameter also applies to a -C80 or -C71 part when operated with t
2.
This parameter also applies to a -C80 part when operated with t
Q,MIN
3.
t
3 specified t
and t
Q,MAX
CYCLE
for other t
values.
CYCLE
values can be interpolated between or extrapolated from the timings at the
Figure 30-1 is a timing diagram which shows the detailed requirements for the RSL clock signals on the Channel.
The CTM and CTMN are differential clock inputs used for transmitting information on the DQA and DQB, outputs.
Most timing is measured relative to the points where they cross. The t
CTM edge to the falling CTM edge. The tCL and tCH parameters are measured from falling to rising and rising to falling
edges of CTM. The tCR and tCF rise-and fall-time parameters are measured at the 20 % and 80 % points.
The CFM and CFMN are differential clock outputs used for receiving information on the DQA, DQB, ROW and COL
outputs. Most timing is measured relative to the points where they cross. The t
falling CFM edge to the falling CFM edge. The tCL and tCH parameters are measured from falling to rising and rising to
falling edges of CFM. The tCR and tCF rise- and fall-time parameters are measured at the 20 % and 80 % points. The
tTR parameters specifies the phase difference that may be tolerated with respect to the CTM and CFM differential
clock inputs (the CTM pair is always earlier).
Figure 30-1 RSL Timing - Clock Signals
t
CYCLE
CTM
t
CL
V
X-
t
CH
t
CR
parameter is measured from the falling
CYCLE
parameter is measured from the
CYCLE
t
CR
V
CM
V
X+
V
CIH
80%
50%
CTMN
CFM
CFMN
20%
V
t
CF
t
TR
t
CR
V
X-
V
CM
V
X+
t
CF
t
CR
CIL
V
CIH
80%
50%
20%
V
t
t
t
CL
t
CYCLE
t
CH
CF
CF
CIL
60
Data Sheet M14837EJ3V0DS00
488448 for Rev. P
µµµµ
PD
31. RSL - Receive Timing
Figure 31-1 is a timing diagram which shows the detailed requirements for the RSL input signals on the Channel.
The DQA, DQB, ROW, and COL signals are inputs which receive information transmitted by a Direct RAC on the
Channel. Each signal is sampled twice per t
sample points are centered at the 0 % and 50 % points of a cycle, measured relative to the crossing points of the
falling CFM clock edge. The set and hold parameters are measured at the V
The tDR and tDF rise- and fall-time parameters are measured at the 20 % and 80 % points of the input transition.
Figure 31-1 RSL Timing - Data Signals for Receive
interval. The set/hold window of the sample points is tS/tH. The
CYCLE
voltage point of the input transition.
REF
CFM
CFMN
DQA
DQB
ROW
COL
VX-
V
CIH
80%
VCM
VX+
50%
20%
V
CIL
0.5•t
CYCLE
t
t
t
DR
t
S
H
t
S
H
V
DIH
80%
even
odd
V
REF
20%
V
t
DF
DIL
Data Sheet M14837EJ3V0DS00
61
PD488448 for Rev. P
µµµµ
32. RSL - Transmit Timing
Figure 32-1 is a timing diagram which shows the detailed requirements for the RSL output signals on the Channel.
The DQA and DQB signals are outputs to transmit information that is received by a Direct RAC on the Channel.
Each signal is driven twice per t
point of the previous cycle and at the 25 % point of the current cycle. The beginning and end of the odd transmit
window is at the 25 % point and at the 75 % point of the current cycle. These transmit points are measured relative to
the crossing points of the falling CTM clock edge. The size of the actual transmit window is less than the ideal
t
/2, as indicated by the non-zero valued of t
CYCLE
point of the output transition.
The tQR and tQF rise- and fall-time parameters are measured at the 20 % and 80 % points of the output transition.
interval. The beginning and end of the even transmit window is at the 75 %
CYCLE
Q,MIN
and t
. The tQ parameters are measured at the 50 % voltage
Q,MAX
Figure 32-1 RSL Timing - Data Signals for Transmit
CTM
CTMN
DQA
DQB
VX-
0.75•t
CYCLE
t
QR
V
CIH
80%
VCM
50%
VX+
20%
V
CIL
V
QH
t
Q,MAX
0.25•t
t
Q,MIN
0.75•t
CYCLE
CYCLE
t
Q,MAX
t
Q,MIN
80%
even
odd
50%
20%
V
t
QF
QL
62
Data Sheet M14837EJ3V0DS00
488448 for Rev. P
µµµµ
PD
33. CMOS - Receive Timing
Figure 33-1 is a timing diagram which shows the detailed requirements for the CMOS input signals.
The CMD and SIO0 signals are inputs which receive information transmitted by a controller (or by another RDRAM’s
SIO1 output). SCK is the CMOS clock signal driven by the controller. All signals are high true.
The cycle time, high phase time, and low phase time of the SCK clock are t
50 % level. The rise and fall times of SCK, CMD, and SIO0 are t
The CMD signal is sampled twice per t
interval, on the rising edge (odd data) and the falling edge (even data).
CYCLE1
DR1
and t
DF1
The set/hold window of the sample points is tS1/tH1. The SCK and CMD timing points are measured at the 50 % level.
The SIO0 signal is sampled once per t
interval on the falling edge. The set/hold window of the sample points
CYCLE1
is tS2/tH2. The SCK and SIO0 timing points are measured at the 50 % level.
Figure 33-1 CMOS Timing - Data Signals for Receive
t
DR2
SCK
, t
CYCLE1
CH1
and t
, all measured at the
CL1
, measured at the 20 % and 80 % levels.
V
IH,CMOS
80%
CMD
t
SIO0
DR1
t
DF2
t
DF1
t
DR2
t
DF2
t
CH1
t
CYCLE1
t
t
S1
even
S2
50%
20%
V
t
CL1
t
H1
t
t
H1
S1
IL,CMOS
V
IH,CMOS
80%
odd
50%
20%
V
IL,CMOS
t
H2
V
IH,CMOS
80%
50%
20%
V
IL,CMOS
Data Sheet M14837EJ3V0DS00
63
PD488448 for Rev. P
µµµµ
The SCK clock is also used for sampling data on RSL input in one situation. Figure23-4 shows the PDN and NAP
exit sequences. If the PSX field of the INIT register is one (Figure 22-1 control registers (1/7) “INIT Register”), then
the PDN and NAP exit sequences are broadcast; i.e. all RDRAMs that are in PDN or NAP will perform the exit
sequence. If the PSX field of the INIT register is zero, then the PDN and NAP exit sequences are directed; i.e. only
one RDRAM that is in PDN or NAP will perform the exit sequence.
The address of that RDRAM is specified on the DQA[5:0] bus in the set hold window tS3/tH3 around the rising edge of
SCK. This is shown Figure 33-2. The SCK timing point is measured at the 50 % level, and the DQA [5:0] bus signals
are measured at the V
REF
level.
Figure 33-2 CMOS Timing - Device Address for NAP or PDN Exit
V
SCK
IH,CMOS
80%
50%
20%
V
IL,CMOS
DQA[5:0]
t
S3
PDEV
t
H3
V
DIH
80%
V
REF
20%
V
DIL
64
Data Sheet M14837EJ3V0DS00
488448 for Rev. P
µµµµ
PD
34. CMOS - Transmit Timing
Figure 34-1 is a timing diagram which shows the detailed requirements for the CMOS output signals. The SIO0
signal is driven once per t
and SIO0 timing points are measured at the 50 % level. The rise and fall times of SIO0 are t
the 20 % and 80 % levels.
Figure34-1 also shows the combinational path connecting SIO0 to SIO1 and the path connecting SIO1 to SIO0
(read data only). The t
input must be t
are t
QR1
and t
QF1
PROP1
and t
DR1
DF1
, measured at the 20 % and 80 % levels.
SCK
interval on the falling edge. The clock-to-output window is t
CYCLE1
Q1,MIN /tQ1,MAX
and t
QR1
. The SCK
, measured at
QF1
parameter specified this propagation delay. The rise and fall times of SIO0 and SIO1
, measured at the 20 % and 80 % levels. The rise and fall times of SIO0 and SIO1 outputs
Figure 34-1 CMOS Timing - Data Signals for Transmit
V
IH,CMOS
80%
50%
SIO0
SIO0
or
SIO1
t
Q1,MAX
t
QF1
t
DF1
t
PROP1,MAX
t
HR,MIN
t
PROP1,MIN
t
QR1
t
DR1
t
QR1
20%
V
IL,CMOS
V
OH,CMOS
80%
50%
20%
V
OL,CMOS
V
IH,CMOS
80%
50%
20%
V
IL,CMOS
SIO0
or
SIO1
t
QF1
Data Sheet M14837EJ3V0DS00
V
OH,CMOS
80%
50%
20%
V
OL,CMOS
65
PD488448 for Rev. P
µµµµ
35. RSL - Domain Crossing Window
When read data is returned by the RDRAM, information must cross from the receive clock domain (CFM) to the
transmit clock domain (CTM). The tTR parameter permits the CFM to CTM phase to vary though an entire cycle ; i.e.
there is no restriction on the alignment of these two clocks. A second parameter t
how the delay between a RD command packet and read data packet varies as a function of the tTR value.
Figure 35-1 shows this timing for five distinct values of tTR. Case A (tTR=0) is what has been used throughout this
document. The delay between the RD command and read data is t
through E), the command to data delay is (t
data delay can also be (t
value is in the range (t
CYCLE+tDCW,MIN
CAC-tTR-tCYCLE
). This is shown as cases A’ and B’ (the gray packets). Similarly, when the t
) to t
CYCLE
). When the tTR value is in the range 0 to t
CAC-tTR
, the command to data delay can also be (t
. As tTR varies from zero to t
CAC
as cases D’ and E’ (the gray packets). The RDRAM will work reliably with either the white or gray packet timing. The
delay value is selected at initialization, and remains fixed thereafter.
Row Cycle time of RDRAM banks - the interval between ROWA packets
t
RC
with ACT commands to the same bank.
RAS-asserted time of RDRAM bank - the interval between ROWA packet
t
RAS
with ACT command and next ROWR packet with PRER
Note 1
command to the
same bank.
Row Precharge time of RDRAM banks - the interval between ROWR packet
t
RP
with PRER
Note 1
command and next ROWA packet with ACT command to the
same bank.
Precharge-to-precharge time of RDRAM device - the interval bet ween
t
PP
successive ROWR packets with PRER
Note 1
commands to any banks of
the same device.
RAS-to-RAS time of RDRAM device - the inte rval between successive
t
RR
ROWA packets with ACT c om m ands to any banks of the sam e device.
RAS-to-CAS Delay - the interval from ROWA packet with ACT
t
RCD
command to COLC packet wi th RD or WR command. Note - the RAS to-CAS delay seen by t he RDRAM core (t
t
because of differences i n the row and column paths through the
RCD
) is equal to t
RCD-C
RCD-C = 1
RDRAM interface.
CAS Access delay - the interval from RD command to Q read data. The
t
CAC
equation for t
CAS Write Delay - interval from WR command to D writ e data.6666t
t
CWD
CAS-to-CAS time of RDRAM bank - the interval bet ween successive
t
CC
is given in the TPARM register in Figure 22-1(5/7).
CAC
COLC commands.
Length of ROWA, ROWR, COLC, COLM or COLX pac ket.4444t
t
PACKET
Interval from COLC pack et with WR command to COLC packet which
t
RTR
causes retire, and to COLM pac ket with bytemask.
The interval (offset) f rom COLC packet with RDA command, or f rom
t
OFFP
COLC packet with retire command (after WRA automatic prec harge), or
from COLC packet with PREC command, or from COLX packet wi t h
PREX command to the equiv al ent ROWR packet with PRER. The
equation for t
Interval from last COLC packet with RD command to ROWR packet
t
RDP
is given in the TPARM register in Figure 22-1(5/7).
OFFP
with PRER.
Interval from last COLC packet with automatic retire command to
t
RTP
ROWR packet with PRER.
282828—t
202020
888—t
888—t
888—t
977—t
+
88812t
444—t
888—t
4444t
444—t
444—t
Note 2
64µs
CYCLE
t
CYCLE
CYCLE
CYCLE
CYCLE
CYCLE
CYCLE
CYCLE
CYCLE
CYCLE
CYCLE
CYCLE
CYCLE
CYCLE
Figure13-1
Figure14-1
Figure13-1
Figure14-1
Figure13-1
Figure14-1
Figure10-3
Figure12-1
Figure13-1
Figure14-1
Figure4-1
Figure4-1
Figure13-1
Figure14-1
Figure2-1
Figure15-1
Figure14-2
Figure13-1
Figure14-1
Notes 1.
Or equivalent PREC or PREX command. See Figure 12-2.
2. This is a constraint imposed by the core, and is therefore in units of ms rather than t
Data Sheet M14837EJ3V0DS00
CYCLE
.
67
37. Absolute Maximum Ratings
Absolute Maximum Ratings
PD488448 for Rev. P
µµµµ
V
I,ABS
V
DD,ABS
T
STORE
Symbol
,V
DDa,ABS
Voltage applied to any RSL or CMOS pi n wi t h respect to GND–0.3VDD +0.3V
Voltage on VDD and V
Storage temperature–50+100
ParameterMIN.MAX.Unit
with respect to GND–0.5VDD +1.0V
DDa
Caution Exposing the device to stress above those listed in Absolute Maximum Ratings could cause
permanent damage. The device is not meant to be operated under conditions outside the limits
described in the operational section of this specification. Exposure to Absolute Maximum Rating
conditions for extended periods may affect device reliability.
38. IDD - Supply Current Profile
IDD - Supply Current Profile
I
value
DD
I
DD,PDN
I
DD,NAP
I
DD,STBY
I
DD,ATTN
I
DD,ATTN-W
I
DD,ATTN-R
RDRAM blocks consuming power@ t
Self-refresh only for INIT.LSR=0
T/RCLK-Nap
T/RCLK,ROW-demux2.50 ns
The CMOS interface consumes power in all power states.
This does not include the I
sink current. The RDRAM dissipates I
OL
one is driven.
Data Sheet M14837EJ3V0DS00
VOL in each output driver when a logic
OL
•
488448 for Rev. P
µµµµ
PD
Capacitance and Inductance
39.
Figure 39-1 shows the equivalent load circuit of the RSL and CMOS pins. The circuit models the load that the device
presents to the Channel.
This circuit does not include pin coupling effects that are often present in the packaged device. Because coupling
effects make the effective single-pin inductance LI, and capacitance CI, a function of neighboring pins, these
parameters are intrinsically data-dependent. For purposes of specifying the device electrical loading on the Channel,
the effective LI and CI are defined as the worst-case values over all specified operating conditions.
LI is defined as the effective pin inductance based on the device pin assignment. Because the pad assignment
places each RSL signal adjacent to an AC ground (a GND or VDD pin), the effective inductance must be defined
based on this configuration. Therefore, LI assumes a loop with the RSL pin adjacent to an AC ground.
CI is defined as the effective pin capacitance based on the device pin assignment. It is the sum of the effective
package pin capacitance and the IO pad capacitance.
Figure 39-1 Equivalent Load Circuit for RSL Pins
Pad
Pad
Pad
L
I
C
I
R
I
L
I
C
I
R
I
L
I,CMOS
C
I
DQA,DQB,RQ Pin
GND Pin
CTM,CTMN,
CFM,CFMN Pin
GND Pin
SCK,CMD Pin
Pad
C
I,CMOS,SIO
L
I,CMOS
Data Sheet M14837EJ3V0DS00
GND Pin
SIO0,SIO1 Pin
GND Pin
69
PD488448 for Rev. P
µµµµ
RSL Pin Parasitics
SymbolParameter and Condit i ons - RSL pinsMIN.MAX.Unit
L
I
L
12
RSL effective input i nduc tance–4.0nH
Mutual inductance between any DQA or DQB RSL signals.–0.2nH
Mutual inductance between any ROW or COL RSL signals.–0.6nH
L
I
∆
C
I
Difference in LI value between any RSL pins of a s i ngl e device.–1.8nH
RSL effective input c apacitance
Note
800 MHz2.02. 4pF
711 MHz2.02. 4
600 MHz2.02. 6
C
12
C
I
∆
R
I
This value is a combination of the device IO circuitry and package capacitances.
Note
Mutual capacitance between any RSL signals.–0.1pF
Difference in CI value between any RSL pins of a s i ngl e device.–0.06pF
RSL effective input res i stance415
CMOS Pin Parasitics
SymbolParameter and Conditions - CMOS pinsMIN.MAX.Unit
L
This value is a combination of the device IO circuitry and package capacitances.
Note
70
Data Sheet M14837EJ3V0DS00
488448 for Rev. P
µµµµ
PD
40. Glossary of Terms
ACTActivate command from AV field.DWrite data packet on DQ pins.
activateTo access a roe and place in sense amp.DBLCNFGB register field – doubled-bank.
activateTo access a row and place in sense amp.DCDevice address field in COLC pac ket.
adjacentdeviceAn RDRAM on a Channel.Two RDRAM banks which share sense amps
(also called doubled banks).
OL
ASYMCCA register field for RSL V
ATTNPower state – ready for ROW / COL packets.DMDev i ce match for ROW packet dec ode.
ATTNRPower state – transmitti ng Q packets.Doubled-bankRDRAM with shared sense amp.
ATTNWPower state – receiving D pac kets.DQDQA and DQB pins.
AVOpcode field in ROW packets.DQAPins for data byte A.
RBIT
CBIT
2
bankDQBPins f or dat a byte B.A block of 2
of the RDRAM.
BCBank address field in CLC packet.DR,DR4T,DR4F
BBITCNFGA register field - # bank address bits.
broadcastAn operat i on executed by all RDRAMs.dualoct16 byt es – the smallest address abl e datum.
BRBank address field in ROW packets .DXDevice address field in COLX packet.
bubblefieldA collection of bits in a packet.Idle cycle(s) on RDRAM pins needed
because of a resource const rai nt.
BYTCNFGB regist er field – 9 bits per byte.init i al i zation
BXBank address field in COLX packet.
CColumn address field in COLC packet.LSRCNFGA regi ster field – low-power self-refres h.
CALCalibrate (I
CBITCNFGB regist er field - # column address bits .MAF i el d i n COLM packet for masking byte A.
CCAControl regi ster – current control A.MBField in COLM pac ket for masking byte B.
CCBControl regi ster – current control B.MSKMask command in M field.
CFM,CFMNClock pins for receiv i ng packets.MVERControl regis ter – manufacturer ID.
ChannelROW / COL / DQ pi ns and external wires.NAPP ower state – needs SCK/CMD wakeup.
CLRRClear reset command from SOP field.NAPRNap c om m and i n ROP field.
CMDCMOS pins f or i ni tialization / power control .NAPRCConditional nap command in ROP field.
CNFGAControl register with configuration fields.NAPXANAPX register field – NAP exit delay A.
CNFGBControl register with configuration fields.NAPXBNAPX register field – NAP exit delay B.
COLPins for col um n-access control.NOCOPNo-operation command in COP field.
COLCColumn operation packet on COL pins.NOROPNo-operation comm and i n ROP field.
COLMWrite mask packet on COL pins.NOXOPNo-operati on command in XOP field.
columnNSRINIT register fiel d – NAP self-refresh.Rows in a bank or activated in sense amps
CommandA decoded bit-combination from a f i el d.PDNPower s tate – needs SCK/CMD wakeup.
COLXExtended operation packet on COL pins.PDNRPowerdown command in ROP field.
controllerPDNXAControl register – PDN exit del ay A.A logic-device which drives the ROW / COL
COPColumn opcode field in COLC packet.pi n efficiencyThe fraction of non-idle cycles on a pin.
coreThe banks and s ense amps of an RDRAM.PREPREC, PRER, PREX precharge commands.
CTM, CTMNClock pins for transmi t ting packets.PRECPrecharge c om m and i n COP field.
Current controlprechargePrepares sense amp and bank for act i vate.Periodic operations to update the proper I
CBTI
have 2
/ DQ wires for a Channel of RDRAMs.
Value of RSL output drivers.
dualocts column st orage.
storage cells in the core
•
OL
) command in XOP field.MMask opcode fi el d (COLM / COLX packet).
/ VOH.
DEVID
DQSNAPX register field – PDN/NAP exit.
INITControl register with initialization f i el ds.
packetA collect i on of bits carried on the Channel.
PDNXBControl register – PDN exit del ay B.
OL
PRERPrecharge command in ROP field.
Control register with devic e address that is
matched against DR, DC, and DX fields.
Device address field and pac k et framing fields
in ROW and ROWE packets.
Configuring a Channel of RDRAMs so t hey
are ready to respond to transact i ons .
Data Sheet M14837EJ3V0DS00
71
PD488448 for Rev. P
µµµµ
PREXPrecharge command in XOP field.SETFSet fast clock c om m and from SOP field.
PSXINIT register field – PDN/ NAP exit.S E T RSet reset command from S OP field.
PSRINIT regis t er field – PDN self-refres h.SINT
PVERCNFGB register field – protocol version.
Serial interval packet for control register
read/write transactions .
QRead data pack et on DQ pins.SIO0,S IO1CMOS serial pins for c ont rol regi sters.
RRow address field of ROWA packet.SOPSerial opcode field in SRQ.
RBITCNFGB regist er field - #row address bits.S RDSerial read opcode command from SOP.
RD/RDARead (/precharge) command in COP field.SRPINIT register field – Serial repeat bit .
readOperation of accessing s ense amp data.SRQ
receive
Moving information from the Channel into the
RDRAM (a serial stream i s demuxed).
STBYP ower state – ready for ROW packets.
Serial request packet f or control register
read/write transactions .
REFARefresh-acti vate command in ROP field.SVERControl register – stepping version.
REFBControl regi ster – next bank (self-refresh).SWRSerial write opcode comm and f rom SOP.
CAS
and t
delay.
delay.
core delay.CNFGA register field – ignore bank bits (for
CLS
core delay.
CLS
delay.
REFBITTCASTCLSCAS register f i el d – t
REFA and self-refresh).
REFPRefres h-precharge command in ROP field.TCLSCASControl register – t
REFRControl register – next row f or REFA.TCYCLEControl register – t
refreshPeriodic operations to restore storage cells.TDA TControl register – t
TCLSTCLSCAS register field – t
CAS
CYCLE
DAC
retireTEST77Control register – for test purpos es.The automatic operation that stores write
buffer into sense amp aft er WR command.
RLXRLXC, RLX R, RLXX relax commands.TRDLYControl register – t
TEST78Control register – for test purpos es.
RDLY
delay.
RLXCRelax command in COP field.transactionROW, COL, DQ packets for memory access.
RLXRRelax command in ROP field.transmit
RLXXRelax command i n XOP field.
Moving information from the RDRAM onto
the Channel (parallel word is muxed).
ROPRow-opcode field in ROWR packet.WR/WRAWrite (/precharge) command in COP field.
CBIT
row2
dualocts of cells (bank/sense amp).wri teOperation of modifying sense amp data.
ROWPins for row-access c ontrolXOPExtended opcode field in COLX pack et.
ROWROWA or ROWR packets on ROW pins.
ROWAActivate packet on ROW pins.
ROWRRow operation packet on ROW pi ns.
RQAlternate nam e for ROW/COL pins.
RSLRambus Si gnal l evels.
OL
SAMSample (I
) command in XOP field.
SASerial address packet for control register
transactions w/ SA address field.
SBCSerial broadcast field in SRQ.
SCKCMOS clock pin.
SDSerial dat a packet for control register
transactions w/ SD dat a field.
SDEVSerial device address i n SRQ packet.
SDEVIDINIT regi s ter field – Serial device I D.
self-refreshRefresh mode for PDN and NAP.
sense ampFast storage that holds copy of bank’s row.
Note:
Strong electric field, when exposed to a MOS device, can cause destruction of the gate oxide and
ultimately degrade the device operation. Steps must be taken to stop generation of static electricity
as much as possible, and quickly dissipate it once, when it has occurred. Environmental control
must be adequate. When it is dry, humidifier should be used. It is recommended to avoid using
insulators that easily build static electricity. Semiconductor devices must be stored and transported
in an anti-static container, static shielding bag or conductive material. All test and measurement
tools including work bench and floor should be grounded. The operator should be grounded using
wrist strap. Semiconductor devices must not be touched with bare hands. Similar precautions need
to be taken for PW boards with semiconductor devices on it.
2HANDLING OF UNUSED INPUT PINS FOR CMOS
Note:
No connection for CMOS device inputs can be cause of malfunction. If no connection is provided
to the input pins, it is possible that an internal input level may be generated due to noise, etc., hence
causing malfunction. CMOS devices behave differently than Bipolar or NMOS devices. Input levels
of CMOS devices must be fixed high or low by using a pull-up or pull-down circuitry. Each unused
DD
pin should be connected to V
being an output pin. All handling related to the unused pins must be judged device by device and
related specifications governing the devices.
or GND with a resistor, if it is considered to have a possibility of
3STATUS BEFORE INITIALIZATION OF MOS DEVICES
Note:
Power-on does not necessarily define initial status of MOS device. Production process of MOS
does not define the initial operation status of the device. Immediately after the power source is
turned ON, the devices with reset function have not yet been initialized. Hence, power-on does
not guarantee out-pin levels, I/O settings or contents of registers. Device is not initialized until the
reset signal is received. Reset operation must be executed immediately after power-on for devices
having reset function.
Data Sheet M14837EJ3V0DS00
79
PD488448 for Rev. P
µµµµ
[MEMO]
D2BGA is a trademark of NEC Corporation.
BGA is a registered trademark of Tessera, Inc.
µµµµ
Rambus and RDRAM are registered trademarks of Rambus Inc.
Direct Rambus, Direct RDRAM and RIMM are trademarks of Rambus Inc.
•
The information in this document is current as of August, 2000. The information is subject to
change without notice. For actual design-in, refer to the latest publications of NEC's data sheets or
data books, etc., for the most up-to-date specifications of NEC semiconductor products. Not all
products and/or types are available in every country. Please check with an NEC sales representative
for availability and additional information.
•
No part of this document may be copied or reproduced in any form or by any means without prior
written consent of NEC. NEC assumes no responsibility for any errors that may appear in this document.
•
NEC does not assume any liability for infringement of patents, copyrights or other intellectual property rights of
third parties by or arising from the use of NEC semiconductor products listed in this document or any other
liability arising from the use of such products. No license, express, implied or otherwise, is granted under any
patents, copyrights or other intellectual property rights of NEC or others.
•
Descriptions of circuits, software and other related information in this document are provided for illustrative
purposes in semiconductor product operation and application examples. The incorporation of these
circuits, software and information in the design of customer's equipment shall be done under the full
responsibility of customer. NEC assumes no responsibility for any losses incurred by customers or third
parties arising from the use of these circuits, software and information.
•
While NEC endeavours to enhance the quality, reliability and safety of NEC semiconductor products, customers
agree and acknowledge that the possibility of defects thereof cannot be eliminated entirely. To minimize
risks of damage to property or injury (including death) to persons arising from defects in NEC
semiconductor products, customers must incorporate sufficient safety measures in their design, such as
redundancy, fire-containment, and anti-failure features.
•
NEC semiconductor products are classified into the following three quality grades:
"Standard", "Special" and "Specific". The "Specific" quality grade applies only to semiconductor products
developed based on a customer-designated "quality assurance program" for a specific application. The
recommended applications of a semiconductor product depend on its quality grade, as indicated below.
Customers must check the quality grade of each semiconductor product before using it in a particular
application.
"Standard": Computers, office equipment, communications equipment, test and measurement equipment, audio
and visual equipment, home electronic appliances, machine tools, personal electronic equipment
and industrial robots
systems, anti-crime systems, safety equipment and medical equipment (not specifically designed
for life support)
"Specific": Aircraft, aerospace equipment, submersible repeaters, nuclear reactor control systems, life
support systems and medical equipment for life support, etc.
The quality grade of NEC semiconductor products is "Standard" unless otherwise expressly specified in NEC's
data sheets or data books, etc. If customers wish to use NEC semiconductor products in applications not
intended by NEC, they must contact an NEC sales representative in advance to determine NEC's willingness
to support a given application.
(Note)
(1) "NEC" as used in this statement means NEC Corporation and also includes its majority-owned subsidiaries.
(2) "NEC semiconductor products" means any semiconductor product developed or manufactured by or for
NEC (as defined above).
M8E 00. 4
Loading...
+ hidden pages
You need points to download manuals.
1 point = 1 manual.
You can buy points or you can get point for every manual you upload.