Datasheet MT48LC2M32B2TG-6, MT48LC2M32B2TG-7, MT48LC2M32B2TG-5, MT48LC2M32B2TG-55 Datasheet (MICRON)

1
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
2 Meg x 32
Configuration 512K x 32 x 4 banks Refresh Count 4K Row Addressing 2K (A0-A10) Bank Addressing 4 (BA0, BA1) Column Addressing 256 (A0-A7)
PIN ASSIGNMENT (TOP VIEW)
86-PIN TSOP
FEATURES
• PC100 functionality
• Fully synchronous; all signals registered on positive edge of system clock
• Internal pipelined operation; column address can be changed every clock cycle
• Internal banks for hiding row access/precharge
• Programmable burst lengths: 1, 2, 4, 8, or full page
• Auto Precharge, includes CONCURRENT AUTO PRECHARGE, and Auto Refresh Modes
• Self Refresh Mode
• 64ms, 4,096-cycle refresh (15.6µs/row)
• LVTTL-compatible inputs and outputs
• Single +3.3V ±0.3V power supply
• Supports CAS latency of 1, 2, and 3
OPTIONS MARKING
• Configuration 2 Meg x 32 (512K x 32 x 4 banks) 2M32B2
• Plastic Package - OCPL
1
86-pin TSOP (400 mil) TG
• Timing (Cycle Time)
5ns (200 MHz) -5
5.5ns (183 MHz) -55 6ns (166 MHz) -6 7ns (143 MHz) -7
• Operating Temperature Range Commercial (0° to +70°C) None Extended (-40°C to +85°C) IT
2
NOTE: 1. Off-center parting line
2. Available on -7
Part Number Example:
MT48LC2M32B2TG-7
Note: The # symbol indicates signal is active LOW.
V
DD
DQ0
V
DD
Q
DQ1 DQ2
V
SS
Q
DQ3 DQ4
V
DD
Q
DQ5 DQ6
V
SS
Q
DQ7
NC
V
DD
DQM0
WE#
CAS# RAS#
CS#
NC BA0 BA1
A10
A0
A1
A2
DQM2
V
DD
NC
DQ16
V
SS
Q
DQ17 DQ18
V
DD
Q
DQ19 DQ20
V
SS
Q
DQ21 DQ22
V
DD
Q
DQ23
V
DD
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43
86 85 84 83 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44
V
SS
DQ15
V
SS
Q
DQ14 DQ13
V
DD
Q
DQ12 DQ11
V
SS
Q
DQ10 DQ9
V
DD
Q
DQ8
NC
V
SS
DQM1
NC
NC
CLK CKE
A9 A8 A7 A6 A5 A4 A3
DQM3 V
SS
NC
DQ31
V
DD
Q
DQ30 DQ29
V
SS
Q
DQ28 DQ27
V
DD
Q
DQ26 DQ25
V
SS
Q
DQ24
V
SS
SYNCHRONOUS DRAM
MT48LC2M32B2 - 512K x 32 x 4 banks
For the latest data sheet, please refer to the Micron Web site: www.micron.com/sdramds
KEY TIMING PARAMETERS
SPEED CLOCK ACCESS TIME SETUP HOLD
GRADE FREQUENCY CL = 3* TIME TIME
-5 200 MHz 4.5ns 1.5ns 1ns
-55 183 MHz 5ns 1.5ns 1ns
-6 166 MHz 5.5ns 1.5ns 1ns
-7 143 MHz 5.5ns 2ns 1ns
*CL = CAS (READ) latency
2
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
The SDRAM provides for programmable READ or WRITE burst lengths of 1, 2, 4, or 8 locations, or the full page, with a burst terminate option. An auto precharge function may be enabled to provide a self-timed row precharge that is initiated at the end of the burst se­quence.
The 64Mb SDRAM uses an internal pipelined archi­tecture to achieve high-speed operation. This archi­tecture is compatible with the 2n rule of prefetch archi­tectures, but it also allows the column address to be changed on every clock cycle to achieve a high-speed, fully random access. Precharging one bank while ac­cessing one of the other three banks will hide the precharge cycles and provide seamless, high-speed, random-access operation.
The 64Mb SDRAM is designed to operate in 3.3V, low-power memory systems. An auto refresh mode is provided, along with a power-saving, power-down mode. All inputs and outputs are LVTTL-compatible.
SDRAMs offer substantial advances in DRAM oper­ating performance, including the ability to synchro­nously burst data at a high data rate with automatic column-address generation, the ability to interleave between internal banks to hide precharge time and the capability to randomly change column addresses on each clock cycle during a burst access.
GENERAL DESCRIPTION
The 64Mb SDRAM is a high-speed CMOS, dynamic random-access memory containing 67,108,864-bits. It is internally configured as a quad-bank DRAM with a synchronous interface (all signals are registered on the positive edge of the clock signal, CLK). Each of the 16,777,216-bit banks is organized as 2,048 rows by 256 columns by 32 bits.
Read and write accesses to the SDRAM are burst oriented; accesses start at a selected location and con­tinue for a programmed number of locations in a pro­grammed sequence. Accesses begin with the registra­tion of an ACTIVE command, which is then followed by a READ or WRITE command. The address bits regis­tered coincident with the ACTIVE command are used to select the bank and row to be accessed (BA0, BA1 select the bank, A0-A10 select the row). The address bits registered coincident with the READ or WRITE com­mand are used to select the starting column location for the burst access.
64Mb (x32) SDRAM PART NUMBER
PART NUMBER ARCHITECTURE
MT48LC2M32B2TG 2 Meg x 32
3
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
TABLE OF CONTENTS
Functional Block Diagram - 2 Meg x 32 ................. 4
Pin Descriptions ..................................................... 5
Functional Description ......................................... 6
Initialization ...................................................... 6
Register Definition ............................................ 6
Mode Register ............................................... 6
Burst Length ............................................ 6
Burst Type ............................................... 7
CAS Latency ............................................ 8
Operating Mode ...................................... 8
Write Burst Mode .................................... 8
Commands ............................................................ 9
Truth Table 1 (Commands and DQM Operation) ............ 9
Command Inhibit ............................................. 10
No Operation (NOP) .......................................... 10
Load Mode Register ........................................... 10
Active ................................................................ 10
Read ................................................................ 10
Write ................................................................ 10
Precharge ........................................................... 10
Auto Precharge .................................................. 10
Burst Terminate ................................................. 11
Auto Refresh ...................................................... 11
Self Refresh ........................................................ 11
Operation ............................................................... 12
Bank/Row Activation ........................................ 12
Reads ................................................................ 13
Writes ................................................................ 19
Precharge ........................................................... 21
Power-Down ...................................................... 21
Clock Suspend .................................................. 22
Burst Read/Single Write .................................... 22
Concurrent Auto Precharge .............................. 23
Write with Auto Precharge ............................... 24
Truth Table 2 (CKE) ................................................ 25
Truth Table 3 (Current State, Same Bank) ..................... 26
Truth Table 4 (Current State, Different Bank) ................. 28
Absolute Maximum Ratings .................................. 30
DC Electrical Characteristics
and Operating Conditions ...................................... 30
I
DD Specifications and Conditions ......................... 30
Capacitance ............................................................ 32
AC Electrical Characteristics (Timing Table) .... 32
AC Electrical Characteristics ................................... 34
Timing Waveforms
Initialize and Load Mode Register .................... 36
Power-Down Mode .......................................... 37
Clock Suspend Mode ........................................ 38
Auto Refresh Mode ........................................... 39
Self Refresh Mode ............................................. 40
Reads
Read – Single Read ....................................... 41
Read – Without Auto Precharge ................. 42
Read – With Auto Precharge ....................... 43
Alternating Bank Read Accesses .................. 44
Read – Full-Page Burst ................................. 45
Read – DQM Operation .............................. 46
Writes
Write – Single Write ..................................... 47
Write – Without Auto Precharge ................ 48
Write – With Auto Precharge ...................... 49
Alternating Bank Write Accesses ................. 50
Write – Full-Page Burst ................................ 51
Write – DQM Operation ............................. 52
4
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
FUNCTIONAL BLOCK DIAGRAM
2 Meg x 32 SDRAM
11
RAS#
CAS#
CLK
CS#
WE#
CKE
8
A0-A10,
BA0, BA1
DQM0­DQM3
13
256
(x32)
8192
I/O GATING
DQM MASK LOGIC
READ DATA LATCH
WRITE DRIVERS
COLUMN
DECODER
BANK0
MEMORY
ARRAY
(2,048 x 256 x 32)
BANK0
ROW-
ADDRESS
LATCH
&
DECODER
2048
SENSE AMPLIFIERS
BANK
CONTROL
LOGIC
DQ0- DQ31
32
32
DATA INPUT
REGISTER
DATA
OUTPUT
REGISTER
32
BANK1
BANK0
BANK2
BANK3
11
8
2
4 4
2
REFRESH
COUNTER
11
11
MODE REGISTER
CONTROL
LOGIC
COMMAND
DECODE
ROW-
ADDRESS
MUX
ADDRESS REGISTER
COLUMN­ADDRESS
COUNTER/
LATCH
5
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
PIN DESCRIPTIONS
PIN NUMBERS SYMBOL TYPE DESCRIPTION
68 CLK Input Clock: CLK is driven by the system clock. All SDRAM input signals are
sampled on the positive edge of CLK. CLK also increments the internal burst counter and controls the output registers.
67 CKE Input Clock Enable: CKE activates (HIGH) and deactivates (LOW) the CLK signal.
Deactivating the clock provides PRECHARGE POWER-DOWN and SELF REFRESH operation (all banks idle), ACTIVE POWER-DOWN (row active in any bank) or CLOCK SUSPEND operation (burst/access in progress). CKE is synchronous except after the device enters power-down and self refresh modes, where CKE becomes asynchronous until after exiting the same mode. The input buffers, including CLK, are disabled during power-down and self refresh modes, providing low standby power. CKE may be tied HIGH.
20 CS# Input Chip Select: CS# enables (registered LOW) and disables (registered HIGH) the
command decoder. All commands are masked when CS# is registered HIGH. CS# provides for external bank selection on systems with multiple banks. CS# is considered part of the command code.
17, 18, 19 WE#, CAS#, Input Command Inputs: WE# , CAS#, and RAS# (along with CS#) define the
RAS# command being entered.
16, 71, 28, 59 DQM0- Input Input/Output Mask: DQM is sampled HIGH and is an input mask signal
DQM3 for write accesses and an output enable signal for read accesses. Input data
is masked during a WRITE cycle. The output buffers are placed in a High-Z state (two-clock latency) during a READ cycle. DQM0 corresponds to DQ0­DQ7; DQM1 corresponds to DQ8-DQ15; DQM2 corresponds to DQ16-DQ23; and DQM3 corresponds to DQ24-DQ31. DQM0-DQM3 are considered same state when referenced as DQM.
22, 23 BA0, BA1 Input Bank Address Input(s): BA0 and BA1 define to which bank the ACTIVE, READ,
WRITE or PRECHARGE command is being applied.
25-27, 60-66, 24 A0-A10 Input Address Inputs: A0-A10 are sampled during the ACTIVE command (row-
address A0-A10) and READ/WRITE command (column-address A0-A7 with A10 defining auto precharge) to select one location out of the memory array in the respective bank. A10 is sampled during a PRECHARGE command to determine if all banks are to be precharged (A10 HIGH) or bank selected by BA0, BA1 (LOW). The address inputs also provide the op-code during a LOAD MODE REGISTER command.
2, 4, 5, 7, 8, 10, 11, 13, DQ0-DQ31 Input/ Data I/Os: Data bus. 74, 76, 77, 79, 80, 82, 83, Output 85, 31, 33, 34, 36, 37, 39, 40, 42, 45, 47, 48, 50, 51,
53, 54, 56
14, 21, 30, 57, 69, 70, 73 NC No Connect: These pins should be left unconnected. Pin 70 is reserved
for SSTL reference voltage supply.
3, 9, 35, 41, 49, 55, 75, 81 VDDQ Supply DQ Power Supply: Isolated on the die for improved noise immunity.
6, 12, 32, 38, 46, 52, 78, 84 VSSQ Supply DQ Ground: Provide isolated ground to DQs for improved noise immunity.
1, 15, 29, 43 V
DD
Supply Power Supply: +3.3V ±0.3V. (See note 27 on page 35.)
44, 58, 72, 86 V
SS
Supply Ground.
6
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
FUNCTIONAL DESCRIPTION
In general, this 64Mb SDRAM (512K x 32 x 4 banks) is a quad-bank DRAM that operates at 3.3V and includes a synchronous interface (all signals are registered on the positive edge of the clock signal, CLK). Each of the 16,777,216-bit banks is organized as 2,048 rows by 256 columns by 32-bits.
Read and write accesses to the SDRAM are burst oriented; accesses start at a selected location and con­tinue for a programmed number of locations in a pro­grammed sequence. Accesses begin with the registra­tion of an ACTIVE command, which is then followed by a READ or WRITE command. The address bits regis­tered coincident with the ACTIVE command are used to select the bank and row to be accessed (BA0 and BA1 select the bank, A0-A10 select the row). The address bits (A0-A7) registered coincident with the READ or WRITE command are used to select the starting col­umn location for the burst access.
Prior to normal operation, the SDRAM must be ini­tialized. The following sections provide detailed infor­mation covering device initialization, register defini­tion, command descriptions and device operation.
Initialization
SDRAMs must be powered up and initialized in a predefined manner. Operational procedures other than those specified may result in undefined opera­tion. Once power is applied to VDD and VDDQ (simulta­neously) and the clock is stable (stable clock is defined as a signal cycling within timing constraints specified for the clock pin), the SDRAM requires a 100µs delay prior to issuing any command other than a COMMAND INHIBIT or a NOP. Starting at some point during this 100µs period and continuing at least through the end of this period, COMMAND INHIBIT or NOP commands should be applied.
Once the 100µs delay has been satisfied with at least one COMMAND INHIBIT or NOP command hav­ing been applied, a PRECHARGE command should be applied. All banks must then be precharged, thereby placing the device in the all banks idle state.
Once in the idle state, two AUTO REFRESH cycles must be performed. After the AUTO REFRESH cycles are complete, the SDRAM is ready for Mode Register programming. Because the Mode Register will power up in an unknown state, it should be loaded prior to applying any operational command.
Register Definition
MODE REGISTER
The Mode Register is used to define the specific mode of operation of the SDRAM. This definition in­cludes the selection of a burst length, a burst type, a CAS latency, an operating mode and a write burst mode, as shown in Figure 1. The Mode Register is programmed via the LOAD MODE REGISTER command and will re­tain the stored information until it is programmed again or the device loses power.
Mode Register bits M0-M2 specify the burst length, M3 specifies the type of burst (sequential or inter­leaved), M4-M6 specify the CAS latency, M7 and M8 specify the operating mode, M9 specifies the write burst mode, and M10 is reserved for future use.
The Mode Register must be loaded when all banks are idle, and the controller must wait the specified time before initiating the subsequent operation. Violating either of these requirements will result in unspecified operation.
Burst Length
Read and write accesses to the SDRAM are burst oriented, with the burst length being programmable, as shown in Figure 1. The burst length determines the maximum number of column locations that can be ac­cessed for a given READ or WRITE command. Burst lengths of 1, 2, 4, or 8 locations are available for both the sequential and the interleaved burst types, and a full­page burst is available for the sequential type. The full-page burst is used in conjunction with the BURST TERMINATE command to generate arbitrary burst lengths.
Reserved states should not be used, as unknown operation or incompatibility with future versions may result.
When a READ or WRITE command is issued, a block of columns equal to the burst length is effectively se­lected. All accesses for that burst take place within this block, meaning that the burst will wrap within the block if a boundary is reached. The block is uniquely se­lected by A1-A7 when the burst length is set to two; by A2-A7 when the burst length is set to four; and by A3-A7 when the burst length is set to eight. The remaining (least significant) address bit(s) is (are) used to select the starting location within the block. Full-page bursts wrap within the page if the boundary is reached.
7
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
NOTE: 1. For a burst length of two, A1-A7 select the block-
of-two burst; A0 selects the starting column within the block.
2. For a burst length of four, A2-A7 select the block­of-four burst; A0-A1 select the starting column within the block.
3. For a burst length of eight, A3-A7 select the block­of-eight burst; A0-A2 select the starting column within the block.
4. For a full-page burst, the full row is selected and A0-A7 select the starting column.
5. Whenever a boundary of the block is reached within a given sequence above, the following access wraps within the block.
6. For a burst length of one, A0-A7 select the unique column to be accessed, and mode register bit M3 is ignored.
Table 1
Burst Definition
Burst Starting Column Order of Accesses Within a Burst
Length Address Type = Sequential Type = Interleaved
A0
2
00-1 0-1 11-0 1-0
A1 A0
0 0 0-1-2-3 0-1-2-3
4
0 1 1-2-3-0 1-0-3-2 1 0 2-3-0-1 2-3-0-1 1 1 3-0-1-2 3-2-1-0
A2 A1 A0
0 0 0 0-1-2-3-4-5-6-7 0-1-2-3-4-5-6-7 0 0 1 1-2-3-4-5-6-7-0 1-0-3-2-5-4-7-6 0 1 0 2-3-4-5-6-7-0-1 2-3-0-1-6-7-4-5
8
0 1 1 3-4-5-6-7-0-1-2 3-2-1-0-7-6-5-4 1 0 0 4-5-6-7-0-1-2-3 4-5-6-7-0-1-2-3 1 0 1 5-6-7-0-1-2-3-4 5-4-7-6-1-0-3-2 1 1 0 6-7-0-1-2-3-4-5 6-7-4-5-2-3-0-1 1 1 1 7-0-1-2-3-4-5-6 7-6-5-4-3-2-1-0
Full n = A0-A7
Cn, Cn + 1, Cn + 2
Page
Cn + 3, Cn + 4...
Not Supported
(256) (Location 0 -256)
…Cn - 1,
Cn…
Figure 1
Mode Register Definition
Burst Type
Accesses within a given burst may be programmed to be either sequential or interleaved; this is referred to as the burst type and is selected via bit M3.
The ordering of accesses within a burst is deter­mined by the burst length, the burst type and the start­ing column address, as shown in Table 1.
000
001
010
011
100
101
110
111
M3 = 0
1
2
4
8
Reserved
Reserved
Reserved
Full Page
M3 = 1
1
2
4
8
Reserved
Reserved
Reserved
Reserved
Operating Mode
Standard operation
All other states reserved
0-0-Defined
-
0
1
Burst Type
Sequential
Interleave
CAS Latency
Reserved
1
2
3
Reserved
Reserved
Reserved
Reserved
000
001
010
011
100
101
110
111
Burst Length
M0
Burst lengthCAS Latency B T
A9
A7
A6 A5 A4
A3A8A2A1A0
Mode Register (Mx)
Address Bus
9
7
654
382
1
0
M1M2
M3
M4M5M6
M6 - M0
M8
M7
Op Mode
A10
10
Reserved* WB
0
1
Write Burst Mode
Programmed Burst Length
Single Location Access
M9
1. *Should program
A10, BA0, and BA1= “0” to ensure compatibility with future device
8
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
ALLOWABLE OPERATING
FREQUENCY (MHz)
CAS CAS CAS
SPEED LATENCY = 1 LATENCY = 2 LATENCY = 3
- 5 - - 200
-55 - - 183
- 6 50 100 166
- 7 50 100 143
Reserved states should not be used as unknown operation or incompatibility with future versions may result.
Operating Mode
The normal operating mode is selected by setting M7 and M8 to zero; the other combinations of values for M7 and M8 are reserved for future use and/or test modes. The programmed burst length applies to both READ and WRITE bursts.
Test modes and reserved states should not be used because unknown operation or incompatibility with future versions may result.
Write Burst Mode
When M9 = 0, the burst length programmed via M0-M2 applies to both READ and WRITE bursts; when M9 = 1, the programmed burst length applies to READ bursts, but write accesses are single-location (nonburst) accesses.
CAS Latency
The CAS latency is the delay, in clock cycles, be­tween the registration of a READ command and the availability of the first piece of output data. The la­tency can be set to one, two or three clocks.
If a READ command is registered at clock edge n, and the latency is m clocks, the data will be available by clock edge n + m. The DQs will start driving as a result of the clock edge one cycle earlier (n + m - 1), and provided that the relevant access times are met, the data will be valid by clock edge n + m. For example, assuming that the clock cycle time is such that all relevant access times are met, if a READ command is registered at T0 and the latency is programmed to two clocks, the DQs will start driving after T1 and the data will be valid by T2, as shown in Figure 2. Table 2 below indicates the operat­ing frequencies at which each CAS latency setting can be used.
Figure 2
CAS Latency
Table 2
CAS Latency
CLK
DQ
T2T1 T3T0
CAS Latency = 3
LZ
D
OUT
t
OH
t
COMMAND
NOPREAD
t
AC
NOP
T4
NOP
DON’T CARE
UNDEFINED
CLK
DQ
T2T1T0
CAS Latency = 1
LZ
D
OUT
t
OH
t
COMMAND
NOPREAD
t
AC
CLK
DQ
T2T1 T3T0
CAS Latency = 2
LZ
D
OUT
t
OH
t
COMMAND
NOPREAD
t
AC
NOP
9
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
TRUTH TABLE 1 – COMMANDS AND DQM OPERATION
(Note: 1)
NAME (FUNCTION) CS# RAS# CAS# WE# DQM ADDR DQs NOTES
COMMAND INHIBIT (NOP) H XXXX X X
NO OPERATION (NOP) L H H H X X X
ACTIVE (Select bank and activate row) L L H H X Bank/Row X 3
READ (Select bank and column, and start READ burst) L H L H L/H8Bank/Col X 4
WRITE (Select bank and column, and start WRITE burst) L H L L L/H8Bank/Col Valid 4
BURST TERMINATE L H H L X X Active
PRECHARGE (Deactivate row in bank or banks) L L H L X Code X 5
AUTO REFRESH or SELF REFRESH L L L H X X X 6, 7 (Enter self refresh mode)
LOAD MODE REGISTER L L L L X Op-Code X 2
Write Enable/Output Enable ––––L – Active 8
Write Inhibit/Output High-Z ––––H – High-Z 8
appear following the Operation section; these tables provide current state/next state information.
Commands
Truth Table 1 provides a quick reference of avail­able commands. This is followed by a written descrip­tion of each command. Three additional Truth Tables
NOTE: 1. CKE is HIGH for all commands shown except SELF REFRESH.
2. A0-A10 define the op-code written to the Mode Register.
3. A0-A10 provide row address, BA0 and BA1 determine which bank is made active.
4. A0-A7 provide column address; A10 HIGH enables the auto precharge feature (nonpersistent), while A10 LOW disables the auto precharge feature; BA0 and BA1 determine which bank is being read from or written to.
5. A10 LOW: BA0 and BA1 determine the bank being precharged. A10 HIGH: All banks precharged and BA0 and BA1 are “Don’t Care.”
6. This command is AUTO REFRESH if CKE is HIGH; SELF REFRESH if CKE is LOW.
7. Internal refresh counter controls row addressing; all inputs and I/Os are “Don’t Care” except for CKE.
8. Activates or deactivates the DQs during WRITEs (zero-clock delay) and READs (two-clock delay). DQM0 controls DQ0-DQ7; DQM1 controls DQ8-DQ15; DQM2 controls DQ16-DQ23; and DQM3 controls DQ24-DQ31.
10
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
COMMAND INHIBIT
The COMMAND INHIBIT function prevents new commands from being executed by the SDRAM, re­gardless of whether the CLK signal is enabled. The SDRAM is effectively deselected. Operations already in progress are not affected.
NO OPERATION (NOP)
The NO OPERATION (NOP) command is used to perform a NOP to an SDRAM which is selected (CS# is LOW). This prevents unwanted commands from being registered during idle or wait states. Operations already in progress are not affected.
LOAD MODE REGISTER
The mode register is loaded via inputs A0-A10. See mode register heading in the Register Definition sec­tion. The LOAD MODE REGISTER command can only be issued when all banks are idle, and a subsequent executable command cannot be issued until tMRD is met.
ACTIVE
The ACTIVE command is used to open (or activate) a row in a particular bank for a subsequent access. The value on the BA0 and BA1 inputs selects the bank, and the address provided on inputs A0-A10 selects the row. This row remains active (or open) for accesses until a PRECHARGE command is issued to that bank. A PRECHARGE command must be issued before open­ing a different row in the same bank.
READ
The READ command is used to initiate a burst read access to an active row. The value on the BA0 and BA1 (B1) inputs selects the bank, and the address provided on inputs A0-A7 selects the starting column location. The value on input A10 determines whether or not auto precharge is used. If auto precharge is selected, the row being accessed will be precharged at the end of the READ burst; if auto precharge is not selected, the row will remain open for subsequent accesses. Read data appears on the DQs subject to the logic level on the DQM inputs two clocks earlier. If a given DQMx signal was registered HIGH, the corresponding DQs will be High-Z two clocks later; if the DQMx signal was regis­tered LOW, the corresponding DQs will provide valid data. DQM0 corresponds to DQ0-DQ7, DQM1 corre­sponds to DQ8-DQ15, DQM2 corresponds to DQ16­DQ23 and DQM3 corresponds to DQ24-DQ31.
WRITE
The WRITE command is used to initiate a burst write access to an active row. The value on the BA0 and BA1 inputs selects the bank, and the address provided on inputs A0-A7 selects the starting column location. The value on input A10 determines whether or not auto precharge is used. If auto precharge is selected, the row being accessed will be precharged at the end of the WRITE burst; if auto precharge is not selected, the row will remain open for subsequent accesses. Input data appearing on the DQs is written to the memory array subject to the DQM input logic level appearing coinci­dent with the data. If a given DQM signal is registered LOW, the corresponding data will be written to memory; if the DQM signal is registered HIGH, the correspond­ing data inputs will be ignored, and a WRITE will not be executed to that byte/column location.
PRECHARGE
The PRECHARGE command is used to deactivate the open row in a particular bank or the open row in all banks. The bank(s) will be available for a subsequent row access a specified time (tRP) after the PRECHARGE command is issued. Input A10 determines whether one or all banks are to be precharged, and in the case where only one bank is to be precharged, inputs BA0 and BA1 select the bank. Otherwise BA0 and BA1 are treated as “Don’t Care.” Once a bank has been precharged, it is in the idle state and must be activated prior to any READ or WRITE commands being issued to that bank.
AUTO PRECHARGE
Auto precharge is a feature which performs the same individual-bank PRECHARGE function de­scribed above, without requiring an explicit command. This is accomplished by using A10 to enable auto precharge in conjunction with a specific READ or WRITE command. A PRECHARGE of the bank/row that is ad­dressed with the READ or WRITE command is auto­matically performed upon completion of the READ or WRITE burst, except in the full-page burst mode, where auto precharge does not apply. Auto precharge is non­persistent in that it is either enabled or disabled for each individual READ or WRITE command.
Auto precharge ensures that the precharge is initi­ated at the earliest valid stage within a burst. The user must not issue another command to the same bank until the precharge time (tRP) is completed. This is determined as if an explicit PRECHARGE command was issued at the earliest possible time, as described for each burst type in the Operation section of this data sheet.
11
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
BURST TERMINATE
The BURST TERMINATE command is used to trun­cate either fixed-length or full-page bursts. The most recently registered READ or WRITE command prior to the BURST TERMINATE command will be truncated, as shown in the Operation section of this data sheet.
AUTO REFRESH
AUTO REFRESH is used during normal operation of the SDRAM and is analagous to CAS#-BEFORE-RAS# (CBR) REFRESH in conventional DRAMs. This com­mand is nonpersistent, so it must be issued each time a refresh is required.
The addressing is generated by the internal refresh controller. This makes the address bits “Don’t Care” during an AUTO REFRESH command. The 64Mb SDRAM requires 4,096 AUTO REFRESH cycles every 64ms (tREF), regardless of width option. Providing a distributed AUTO REFRESH command every 15.625µs will meet the refresh requirement and ensure that each row is refreshed. Alternatively, 4,096 AUTO REFRESH commands can be issued in a burst at the minimum cycle rate (tRC), once every 64ms.
SELF REFRESH
The SELF REFRESH command can be used to retain data in the SDRAM, even if the rest of the system is powered down. When in the self refresh mode, the SDRAM retains data without external clocking. The SELF REFRESH command is initiated like an AUTO REFRESH command except CKE is disabled (LOW). Once the SELF REFRESH command is registered, all the inputs to the SDRAM become “Don’t Care” with the exception of CKE, which must remain LOW.
Once self refresh mode is engaged, the SDRAM pro­vides its own internal clocking, causing it to perform its own AUTO REFRESH cycles. The SDRAM must remain in self refresh mode for a minimum period equal to
t
RAS and may remain in self refresh mode for an indefi-
nite period beyond that.
The procedure for exiting self refresh requires a se­quence of commands. First, CLK must be stable (stable clock is defined as a signal cycling within timing con­straints specified for the clock pin) prior to CKE going back HIGH. Once CKE is HIGH, the SDRAM must have NOP commands issued (a minimum of two clocks) for
t
XSR because time is required for the completion of any
internal refresh in progress.
Upon exiting SELF REFRESH mode, AUTO REFRESH commands must be issued every 15.625ms or less as both SELF REFRESH and AUTO REFRESH utililze the row refresh counter.
12
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
Operation
BANK/ROW ACTIVATION
Before any READ or WRITE commands can be is­sued to a bank within the SDRAM, a row in that bank must be “opened.” This is accomplished via the AC­TIVE command, which selects both the bank and the row to be activated. See Figure 3.
After opening a row (issuing an ACTIVE command), a READ or WRITE command may be issued to that row, subject to the tRCD specification. tRCD (MIN) should be divided by the clock period and rounded up to the next whole number to determine the earliest clock edge after the ACTIVE command on which a READ or WRITE command can be issued. For example, a tRCD specifi­cation of 20ns with a 125 MHz clock (8ns period) results in 2.5 clocks, rounded to 3. This is reflected in Figure 4, which covers any case where 2 < tRCD (MIN)/tCK - 3. (The same procedure is used to convert other specifi­cation limits from time units to clock cycles.)
A subsequent ACTIVE command to a different row in the same bank can only be issued after the previous active row has been “closed” (precharged). The mini­mum time interval between successive ACTIVE com­mands to the same bank is defined by tRC.
A subsequent ACTIVE command to another bank can be issued while the first bank is being accessed, which results in a reduction of total row-access over­head. The minimum time interval between successive ACTIVE commands to different banks is defined by
t
RRD.
Figure 4
Example: Meeting tRCD (MIN) When 2 < tRCD (MIN)/tCK - 3
CLK
T2T1 T3T0
t
COMMAND
NOPACTIVE
READ or
WRITE
NOP
RCD (MIN)
t
RCD (MIN) = 20ns, tCK = 8ns
t
RCD (MIN) x tCK
where x = number of clocks for equation to be true.
t
RCD (MIN) +0.5 tCK
t
CK
t
CK
t
CK
DON’T CARE
Figure 3
Activating a Specific Row in a
Specific Bank
CS#
WE#
CAS#
RAS#
CKE
CLK
A0–A10
ROW
ADDRESS
HIGH
BA0, BA1
BANK
ADDRESS
13
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
Upon completion of a burst, assuming no other com­mands have been initiated, the DQs will go High-Z. A full-page burst will continue until terminated. (At the end of the page, it will wrap to column 0 and continue.)
Data from any READ burst may be truncated with a subsequent READ command, and data from a fixed­length READ burst may be immediately followed by data from a READ command. In either case, a continu­ous flow of data can be maintained. The first data ele­ment from the new burst follows either the last ele­ment of a completed burst or the last desired data ele­ment of a longer burst that is being truncated. The new READ command should be issued x cycles before the clock edge at which the last desired data element is valid, where x equals the CAS latency minus one. This is shown in Figure 7 for CAS latencies of one, two and
READs
READ bursts are initiated with a READ command,
as shown in Figure 5.
The starting column and bank addresses are pro­vided with the READ command, and auto precharge is either enabled or disabled for that burst access. If auto precharge is enabled, the row being accessed is precharged at the completion of the burst. For the ge­neric READ commands used in the following illustra­tions, auto precharge is disabled.
During READ bursts, the valid data-out element from the starting column address will be available fol­lowing the CAS latency after the READ command. Each subsequent data-out element will be valid by the next positive clock edge. Figure 6 shows general timing for each possible CAS latency setting.
Figure 5
READ Command
Figure 6
CAS Latency
CLK
DQ
T2T1 T3T0
CAS Latency = 3
LZ
D
OUT
t
OH
t
COMMAND
NOPREAD
t
AC
NOP
T4
NOP
DON’T CARE
UNDEFINED
CLK
DQ
T2T1T0
CAS Latency = 1
LZ
D
OUT
t
OH
t
COMMAND
NOPREAD
t
AC
CLK
DQ
T2T1 T3T0
CAS Latency = 2
LZ
D
OUT
t
OH
t
COMMAND
NOPREAD
t
AC
NOP
CS#
WE#
CAS#
RAS#
CKE
CLK
COLUMN ADDRESS
A0–A7
A10
BA0, 1
HIGH
ENABLE AUTO PRECHARGE
DISABLE AUTO PRECHARGE
BANK
ADDRESS
A8, A9
14
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
three; data element n + 3 is either the last of a burst of four or the last desired of a longer burst. This 64Mb SDRAM uses a pipelined architecture and therefore does not require the 2n rule associated with a prefetch architecture. A READ command can be initiated on any
Figure 7
Consecutive READ Bursts
clock cycle following a previous READ command. Full­speed random read accesses can be performed to the same bank, as shown in Figure 8, or each subsequent READ may be performed to a different bank.
CLK
DQ
D
OUT
n
T2T1 T4T3 T5T0
COMMAND
ADDRESS
READ NOP NOP NOP
BANK, COL n
NOP
BANK,
COL b
D
OUT
n + 1
D
OUT
n + 2
D
OUT
n + 3
D
OUT
b
READ
X = 0 cycles
NOTE: Each READ command may be to either bank. DQM is LOW.
CAS Latency = 1
CLK
DQ
D
OUT
n
T2T1 T4T3 T6T5T0
COMMAND
ADDRESS
READ NOP NOP NOP NOP
BANK, COL n
NOP
BANK,
COL b
D
OUT
n + 1
D
OUT
n + 2
D
OUT
n + 3
D
OUT
b
READ
X = 1 cycle
CAS Latency = 2
CLK
DQ
D
OUT
n
T2T1 T4T3 T6T5T0
COMMAND
ADDRESS
READ NOP NOP NOP NOP
BANK, COL n
NOP
BANK,
COL b
D
OUT
n + 1
D
OUT
n + 2
D
OUT
n + 3
D
OUT
b
READ
NOP
T7
X = 2 cycles
CAS Latency = 3
DON’T CARE
15
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
Figure 8
Random READ Accesses
CLK
DQ
T2T1 T4T3 T6T5T0
COMMAND
ADDRESS
READ NOP NOP
BANK, COL n
DON’T CARE
D
OUT
n
D
OUT
a
D
OUT
x
D
OUT
m
READ
NOTE: Each READ command may be to either bank. DQM is LOW.
READ READ NOP
BANK, COL a
BANK,
COL x
BANK,
COL m
CLK
DQ
D
OUT
n
T2T1 T4T3 T5T0
COMMAND
ADDRESS
READ NOP
BANK, COL n
D
OUT
a
D
OUT
x
D
OUT
m
READ READ READ NOP
BANK, COL a
BANK,
COL x
BANK, COL m
CLK
DQ
D
OUT
n
T2T1 T4T3T0
COMMAND
ADDRESS
READ NOP
BANK, COL n
D
OUT
a
D
OUT
x
D
OUT
m
READ READ READ
BANK, COL a
BANK,
COL x
BANK, COL m
CAS Latency = 1
CAS Latency = 2
CAS Latency = 3
16
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
Data from any READ burst may be truncated with a subsequent WRITE command, and data from a fixed­length READ burst may be immediately followed by data from a WRITE command (subject to bus turn­around limitations). The WRITE burst may be initiated on the clock edge immediately following the last (or last desired) data element from the READ burst, provided that I/O contention can be avoided. In a given system design, there may be a possibility that the device driv­ing the input data will go Low-Z before the SDRAM DQs go High-Z. In this case, at least a single-cycle delay should occur between the last read data and the WRITE command.
DON’T CARE
READ NOP NOPNOP NOP
DQM
CLK
DQ
D
OUT
n
T2T1 T4T3T0
COMMAND
ADDRESS
BANK, COL n
WRITE
DIN b
BANK,
COL b
T5
DS
t
HZ
t
NOTE: A CAS latency of three is used for illustration. The
READ command
may be to any bank, and the WRITE command may be to any bank.
Figure 10
READ to WRITE with
Extra Clock Cycle
Figure 9
READ to WRITE
DON’T CARE
READ NOP NOP
WRITE
NOP
CLK
T2T1 T4T3T0
DQM
DQ
DOUT n
COMMAND
DIN b
ADDRESS
BANK, COL n
BANK, COL b
DS
t
HZ
t
t
CK
NOTE: A CAS latency of three is used for illustration. The
READ
command ma
y
be to any bank, and the WRITE command
The DQM input is used to avoid I/O contention, as shown in Figures 9 and 10. The DQM signal must be asserted (HIGH) at least two clocks prior to the WRITE command (DQM latency is two clocks for output buff­ers) to suppress data-out from the READ. Once the WRITE command is registered, the DQs will go High-Z (or remain High-Z), regardless of the state of the DQM signal; provided the DQM was active on the clock just prior to the WRITE command that truncated the READ command. If not, the second WRITE will be an invalid WRITE. For example, if DQM was low during T4 in Fig­ure 10, then the WRITEs at T5 and T7 would be valid, while the WRITE at T6 would be invalid.
The DQM signal must be de-asserted prior to the WRITE command (DQM latency is zero clocks for input buffers) to ensure that the written data is not masked. Figure 9 shows the case where the clock frequency al­lows for bus contention to be avoided without adding a NOP cycle, and Figure 10 shows the case where the additional NOP is needed.
17
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
Figure 11
READ to PRECHARGE
A fixed-length READ burst may be followed by, or truncated with, a PRECHARGE command to the same bank (provided that auto precharge was not acti­vated), and a full-page burst may be truncated with a PRECHARGE command to the same bank. The PRECHARGE command should be issued x cycles be­fore the clock edge at which the last desired data ele­ment is valid, where x equals the CAS latency minus one. This is shown in Figure 11 for each possible CAS
latency; data element n + 3 is either the last of a burst of four or the last desired of a longer burst. Following the PRECHARGE command, a subsequent command to the same bank cannot be issued until tRP is met. Note that part of the row precharge time is hidden during the access of the last data element(s).
In the case of a fixed-length burst being executed to completion, a PRECHARGE command issued at the optimum time (as described above) provides the same
CLK
DQ
D
OUT
n
T2T1 T4T3 T6T5T0
COMMAND
ADDRESS
READ NOP NOP NOP NOPNOP
D
OUT
n + 1
D
OUT
n + 2
D
OUT
n + 3
PRECHARGE
ACTIVE
t
RP
T7
NOTE: DQM is LOW.
CLK
DQ
D
OUT
n
T2T1 T4T3 T6T5T0
COMMAND
ADDRESS
READ NOP NOP NOP NOPNOP
D
OUT
n + 1
D
OUT
n + 2
D
OUT
n + 3
PRECHARGE
ACTIVE
t
RP
T7
CLK
DQ
D
OUT
n
T2T1 T4T3 T6T5T0
COMMAND
ADDRESS
READ NOP NOP NOP NOP
BANK a,
COL n
NOP
D
OUT
n + 1
D
OUT
n + 2
D
OUT
n + 3
PRECHARGE
ACTIVE
t
RP
T7
BANK a,
ROW
BANK
(a or all)
DON’T CARE
X = 0 cycles
CAS Latency = 1
X = 1 cycle
CAS Latency = 2
CAS Latency = 3
BANK a,
COL
n
BANK a,
ROW
BANK
(a or all)
BANK a,
COL
n
BANK a,
ROW
BANK
(a or all)
X = 2 cycles
18
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
Figure 12
Terminating a READ Burst
operation that would result from the same fixed-length burst with auto precharge. The disadvantage of the PRECHARGE command is that it requires that the com­mand and address buses be available at the appropri­ate time to issue the command; the advantage of the PRECHARGE command is that it can be used to trun­cate fixed-length or full-page bursts.
Full-page READ bursts can be truncated with the
BURST TERMINATE command, and fixed-length READ
bursts may be truncated with a BURST TERMINATE command, provided that auto precharge was not acti­vated. The BURST TERMINATE command should be issued x cycles before the clock edge at which the last desired data element is valid, where x equals the CAS latency minus one. This is shown in Figure 12 for each possible CAS latency; data element n + 3 is the last desired data element of a longer burst.
DON’T CARE
CLK
DQ
D
OUT
n
T2T1 T4T3 T6T5T0
COMMAND
ADDRESS
READ NOP NOP NOP NOP
BANK, COL n
NOP
D
OUT
n + 1
D
OUT
n + 2
D
OUT
n + 3
BURST
TERMINATE
NOP
T7
NOTE: DQM is LOW.
CLK
DQ
D
OUT
n
T2T1 T4T3 T6T5T0
COMMAND
ADDRESS
READ NOP NOP NOP
BANK, COL n
NOP
D
OUT
n + 1
D
OUT
n + 2
D
OUT
n + 3
BURST
TERMINATE
NOP
CLK
DQ
D
OUT
n
T2T1 T4T3 T6T5T0
COMMAND
ADDRESS
READ NOP NOP NOP
BANK, COL n
NOP
D
OUT
n + 1
D
OUT
n + 2
D
OUT
n + 3
BURST
TERMINATE
NOP
X = 0 cycles
CAS Latency = 1
X = 1 cycle
CAS Latency = 2
CAS Latency = 3
X = 2 cycles
19
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
WRITEs
WRITE bursts are initiated with a WRITE command,
as shown in Figure 13.
The starting column and bank addresses are pro­vided with the WRITE command, and auto precharge is either enabled or disabled for that access. If auto precharge is enabled, the row being accessed is precharged at the completion of the burst. For the ge­neric WRITE commands used in the following illustrations,auto precharge is disabled.
During WRITE bursts, the first valid data-in ele­ment will be registered coincident with the WRITE com­mand. Subsequent data elements will be registered on each successive positive clock edge. Upon completion of a fixed-length burst, assuming no other commands have been initiated, the DQs will remain High-Z and any additional input data will be ignored (see Figure
14). A full-page burst will continue until terminated. (At the end of the page, it will wrap to column 0 and continue.)
Data for any WRITE burst may be truncated with a subsequent WRITE command, and data for a fixed­length WRITE burst may be immediately followed by data for a WRITE command. The new WRITE command
Figure 15
WRITE to WRITE
can be issued on any clock following the previous WRITE command, and the data provided coincident with the new command applies to the new command. An ex­ample is shown in Figure 15. Data n + 1 is either the last of a burst of two or the last desired of a longer burst. This 64Mb SDRAM uses a pipelined architecture and therefore does not require the 2n rule associated with a prefetch architecture. A WRITE command can be initi­ated on any clock cycle following a previous WRITE command. Full-speed random write accesses within a page can be performed to the same bank, as shown in Figure 16, or each subsequent WRITE may be per­formed to a different bank.
CLK
DQ
DIN
n
T2T1 T3T0
COMMAND
ADDRESS
NOP NOPWRITE
D
IN
n + 1
NOP
BANK,
COL n
Figure 14
WRITE Burst
CS#
WE#
CAS#
RAS#
CKE
CLK
COLUMN ADDRESS
HIGH
ENABLE AUTO PRECHARGE
DISABLE AUTO PRECHARGE
BANK
ADDRESS
A0–A7
A10
BA0, 1
A8, A9
Figure 13
WRITE Command
CLK
DQ
T2T1T0
COMMAND
ADDRESS
NOPWRITE WRITE
BANK, COL n
BANK,
COL b
D
IN
n
D
IN
n + 1
D
IN
b
NOTE: DQM is LOW. Each WRITE command may
be to any bank.
DON’T CARE
20
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
quency, in auto precharge mode. In addition, when truncating a WRITE burst, the DQM signal must be used to mask input data for the clock edge prior to, and the clock edge coincident with, the PRECHARGE com­mand. An example is shown in Figure 18. Data n + 1 is either the last of a burst of two or the last desired of a longer burst. Following the PRECHARGE command, a subsequent command to the same bank cannot be issued until tRP is met. The precharge will actually be­gin coincident with the clock-edge (T2 in Figure 18) on a “one-clock”
t
WR and sometime between the first and
second clock on a “two-clock”
t
WR (between T2 and T3
in Figure 18.)
In the case of a fixed-length burst being executed to completion, a PRECHARGE command issued at the optimum time (as described above) provides the same operation that would result from the same fixed-length burst with auto precharge. The disadvantage of the PRECHARGE command is that it requires that the com­mand and address buses be available at the appropri­ate time to issue the command; the advantage of the PRECHARGE command is that it can be used to trun­cate fixed-length or full-page bursts.
Figure 18
WRITE to PRECHARGE
Data for any WRITE burst may be truncated with a subsequent READ command, and data for a fixed­length WRITE burst may be immediately followed by a READ command. Once the READ command is regis­tered, the data inputs will be ignored, and WRITEs will not be executed. An example is shown in Figure 17. Data n + 1 is either the last of a burst of two or the last desired of a longer burst.
Data for a fixed-length WRITE burst may be fol­lowed by, or truncated with, a PRECHARGE command to the same bank (provided that auto precharge was not activated), and a full-page WRITE burst may be truncated with a PRECHARGE command to the same bank. The PRECHARGE command should be issued
t
WR after the clock edge at which the last desired input data element is registered. The “two-clock” write-back requires at least one clock plus time, regardless of fre-
Figure 17
WRITE to READ
DON’T CARE
CLK
DQ
T2T1 T3T0
COMMAND
ADDRESS
NOPWRITE
BANK,
COL n
DIN
n
D
IN
n + 1
DOUT
b
READ NOP NOP
BANK, COL b
NOP
D
OUT
b + 1
T4 T5
Figure 16
Random WRITE Cycles
DON’T CAR
E
CLK
DQ
D
IN
n
T2T1 T3T0
COMMAND
ADDRESS
WRITE
BANK, COL n
D
IN
a
D
IN
x
D
IN
m
WRITE
WRITE WRITE
BANK,
COL a
BANK,
COL x
BANK,
COL m
NOTE: Each WRITE command may be to any bank. DQM is LOW.
DON’T CARE
DQM
CLK
DQ
T2T1 T4T3T0
COMMAND
ADDRESS
BANK a,
COL n
T5
NOPWRITE
PRECHARGE
NOPNOP
D
IN
n
D
IN
n + 1
ACTIVE
t
RP
BANK
(a or all)
t
WR
BANK a,
ROW
DQM
DQ
COMMAND
ADDRESS
BANK a,
COL n
NOPWRITE
PRECHARGE
NOPNOP
D
IN
n
D
IN
n + 1
ACTIVE
t
RP
BANK
(a or all)
t
WR
NOTE: DQM could remain LOW in this example if the WRITE burst is a fixed
length of two.
BANK a,
ROW
T6
NOP
NOP
t
WR = 2 CLK (when tWR > tCK)
t
WR = 1 CLK (tCK > tWR)
21
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
Fixed-length or full-page WRITE bursts can be trun­cated with the BURST TERMINATE command. When truncating a WRITE burst, the input data applied coin­cident with the BURST TERMINATE command will be ignored. The last data written (provided that DQM is LOW at that time) will be the input data applied one clock previous to the BURST TERMINATE command. This is shown in Figure 19, where data n is the last desired data element of a longer burst.
Figure 21
Power-Down
DON’T CARE
t
RAS
t
RCD
t
RC
All banks idle
Input buffers gated off
Exit power-down mode.
()(
)
()(
)
()(
)
t
CKS
> t
CKS
COMMAND
NOP ACTIVE
Enter power-down mode.
NOP
CLK
CKE
()(
)
()(
)
Figure 20
PRECHARGE Command
Figure 19
Terminating a WRITE Burst
CLK
DQ
T2T1T0
COMMAND
ADDRESS
BANK, COL n
WRITE
BURST
TERMINATE
NEXT
COMMAND
DIN
n
(ADDRESS)
(DATA)
NOTE: DQMs are LOW.
PRECHARGE
The PRECHARGE command (Figure 20) is used to deactivate the open row in a particular bank or the open row in all banks. The bank(s) will be available for a subsequent row access some specified time (
t
RP) af­ter the PRECHARGE command is issued. Input A10 determines whether one or all banks are to be precharged, and in the case where only one bank is to be precharged, inputs BA0 and BA1 select the bank. When all banks are to be precharged, inputs BA0 and BA1 are treated as “Don’t Care.” Once a bank has been precharged, it is in the idle state and must be activated prior to any READ or WRITE commands being issued to that bank.
POWER-DOWN
Power-down occurs if CKE is registered LOW coinci­dent with a NOP or COMMAND INHIBIT when no ac­cesses are in progress (see Figure 21). If power-down occurs when all banks are idle, this mode is referred to as precharge power-down; if power-down occurs when there is a row active in either bank, this mode is referred to as active power-down. Entering power-down deacti­vates the input and output buffers, excluding CKE, for maximum power savings while in standby. The device may not remain in the power-down state longer than the refresh period (64ms) since no refresh operations are performed in this mode.
The power-down state is exited by registering a NOP or COMMAND INHIBIT and CKE HIGH at the desired clock edge (meeting
t
CKS).
CS#
WE#
CAS#
RAS#
CKE
CLK
A10
HIGH
All Banks
Bank Selected
A0–A9
BA0, 1
BANK
ADDRESS
22
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
DON’T CARE
D
IN
COMMAND
ADDRESS
WRITE
BANK,
COL n
D
IN
n
NOPNOP
CLK
T2T1 T4T3 T5T0
CKE
INTERNAL
CLOCK
NOP
D
IN
n + 1
D
IN
n + 2
Figure 22
CLOCK SUSPEND During WRITE Burst
DON’T CARE
CLK
DQ
D
OUT
n
T2T1 T4T3 T6T5T0
COMMAND
ADDRESS
READ NOP NOP NOP
BANK, COL n
NOP
D
OUT
n + 1
D
OUT
n + 2
D
OUT
n + 3
NOTE: For this example, CAS latency = 2, burst length = 4 or greater, and
DQM is LOW.
CKE
INTERNAL
CLOCK
NOP
Figure 23
CLOCK SUSPEND During READ Burst
CLOCK SUSPEND
The clock suspend mode occurs when a column ac­cess/burst is in progress and CKE is registered LOW. In the clock suspend mode, the internal clock is deacti­vated, “freezing” the synchronous logic.
For each positive clock edge on which CKE is sampled LOW, the next internal positive clock edge is suspended. Any command or data present on the in­put pins at the time of a suspended internal clock edge is ignored; any data present on the DQ pins remains driven; and burst counters are not incremented, as long as the clock is suspended. (See examples in Fig­ures 22 and 23.)
Clock suspend mode is exited by registering CKE HIGH; the internal clock and related operation will re­sume on the subsequent positive clock edge.
BURST READ/SINGLE WRITE
The burst read/single write mode is entered by pro­gramming the write burst mode bit (M9) in the Mode Register to a logic 1. In this mode, all WRITE commands result in the access of a single column location (burst of one), regardless of the programmed burst length. READ commands access columns according to the pro­grammed burst length and sequence, just as in the normal mode of operation (M9 = 0).
23
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
CONCURRENT AUTO PRECHARGE
An access command to (READ or WRITE) another bank while an access command with auto precharge enabled is executing is not allowed by SDRAMs, unless the SDRAM supports CONCURRENT AUTO PRECHARGE. Micron SDRAMs support CONCURRENT AUTO PRECHARGE. Four cases where CONCURRENT AUTO PRECHARGE occurs are defined below.
READ with auto precharge
1. Interrupted by a READ (with or without auto
precharge): A READ to bank m will interrupt a READ
on bank n, CAS latency later. The PRECHARGE to bank n will begin when the READ to bank m is regis­tered (Figure 24).
2. Interrupted by a WRITE (with or without auto precharge): A WRITE to bank m will interrupt a READ on bank n when registered. DQM should be used two clocks prior to the WRITE command to prevent bus contention. The PRECHARGE to bank n will begin when the WRITE to bank m is registered (Fig­ure 25).
CLK
DQ
D
OUT
a
T2T1 T4T3 T6T5T0
COMMAND
READ - AP
BANK n
NOP NOPNOPNOP
D
OUT
a + 1
D
OUT
d
D
OUT
d + 1
NOP
T7
BANK n
CAS Latency = 3 (BANK m)
BANK m
ADDRESS
Idle
NOP
BANK n,
COL a
BANK m,
COL d
READ - AP
BANK m
Internal States
t
Page Active READ with Burst of 4 Interrupt Burst, Precharge
Page Active READ with Burst of 4
Precharge
RP - BANK n
t
RP - BANK m
CAS Latency = 3 (BANK n)
Figure 24
READ With Auto Precharge Interrupted by a READ
CLK
DQ
D
OUT
a
T2T1 T4T3 T6T5T0
COMMAND
NOPNOPNOPNOP
D
IN
d + 1
D
IN
d
D
IN
d + 2
D
IN
d + 3
NOP
T7
BANK n
BANK m
ADDRESS
Idle
NOP
DQM
NOTE: 1. DQM is HIGH at T2 to prevent D
OUT
-a+1 from contending with DIN-d at T4.
BANK n,
COL a
BANK m,
COL d
WRITE - AP
BANK m
Internal States
t
Page Active
READ with Burst of 4 Interrupt Burst, Precharge
Page Active WRITE with Burst of 4
Write-Back
RP -
BANK
n
t
WR -
BANK
m
CAS Latency = 3 (BANK n)
READ - AP
BANK n
1
DON’T CARE
Figure 25
READ With Auto Precharge Interrupted by a WRITE
24
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
CLK
DQ
T2T1 T4T3 T6T5T0
COMMAND
WRITE - AP
BANK n
NOPNOPNOPNOP
D
IN
a + 1
D
IN
a
NOP NOP
T7
BANK n
BANK m
ADDRESS
NOTE: 1. DQM is LOW.
BANK n,
COL a
BANK m,
COL d
READ - AP
BANK m
Internal States
t
Page Active WRITE with Burst of 4 Interrupt Burst, Write-Back Precharge
Page Active READ with Burst of 4
t
t
RP - BANK m
D
OUT
d
D
OUT
d + 1
CAS Latency = 3 (BANK m)
RP - BANK n
WR - BANK n
Figure 26
WRITE With Auto Precharge Interrupted by a READ
DON’T CARE
CLK
DQ
T2T1 T4T3 T6T5T0
COMMAND
WRITE - AP
BANK n
NOPNOPNOPNOP
D
IN
d + 1
D
IN
d
D
IN
a + 1
D
IN
a + 2
D
IN
a
D
IN
d + 2
D
IN
d + 3
NOP
T7
BANK n
BANK m
ADDRESS
NOP
NOTE: 1. DQM is LOW.
BANK n,
COL a
BANK m,
COL d
WRITE - AP
BANK m
Internal States
t
Page Active WRITE with Burst of 4 Interrupt Burst, Write-Back Precharge
Page Active WRITE with Burst of 4
Write-Back
WR - BANK n
t
RP - BANK n
t
WR - BANK m
Figure 27
WRITE With Auto Precharge Interrupted by a WRITE
WRITE WITH AUTO PRECHARGE
3. Interrupted by a READ (with or without auto precharge): A READ to bank m will interrupt a WRITE on bank n when registered, with the data-out ap­pearing CAS latency later. The PRECHARGE to bank n will begin after tWR is met, where tWR begins when the READ to bank m is registered. The last valid WRITE to bank n will be data-in registered one clock prior to the READ to bank m (Figure 26).
4. Interrupted by a WRITE (with or without auto precharge): A WRITE to bank m will interrupt a WRITE on bank n when registered. The PRECHARGE to bank n will begin after
t
WR is met, where tWR begins when the WRITE to bank m is registered. The last valid data WRITE to bank n will be data regis­tered one clock prior to a WRITE to bank m (Figure
27).
25
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
TRUTH TABLE 2 – CKE
(Notes: 1-4)
CKE
n-1
CKE
n
CURRENT STATE COMMAND
n
ACTION
n
NOTES
L L Power-Down X Maintain Power-Down
Self Refresh X Maintain Self Refresh
Clock Suspend X Maintain Clock Suspend
L H Power-Down COMMAND INHIBIT or NOP Exit Power-Down 5
Self Refresh COMMAND INHIBIT or NOP Exit Self Refresh 6
Clock Suspend X Exit Clock Suspend 7
H L All Banks Idle COMMAND INHIBIT or NOP Power-Down Entry
All Banks Idle AUTO REFRESH Self Refresh Entry
Reading or Writing VALID Clock Suspend Entry
H H See Truth Table 3
NOTE: 1. CKEn is the logic state of CKE at clock edge n; CKE
n-1
was the state of CKE at the previous clock edge.
2. Current state is the state of the SDRAM immediately prior to clock edge n.
3. COMMANDn is the command registered at clock edge n, and ACTIONn is a result of COMMANDn.
4. All states and sequences not shown are illegal or reserved.
5. Exiting power-down at clock edge n will put the device in the all banks idle state in time for clock edge n + 1 (provided that tCKS is met).
6. Exiting self refresh at clock edge n will put the device in the all banks idle state once tXSR is met. COMMAND INHIBIT or NOP commands should be issued on any clock edges occurring during the tXSR period. A minimum of two NOP commands must be provided during tXSR period.
7. After exiting clock suspend at clock edge n, the device will resume operation and recognize the next command at clock edge n + 1.
26
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
TRUTH TABLE 3 – CURRENT STATE BANK n, COMMAND TO BANK n
(Notes: 1-6; notes appear below and on next page)
CURRENT STATE CS# RAS# CAS# WE# COMMAND (ACTION) NOTES
Any H X X X COMMAND INHIBIT (NOP/Continue previous operation)
L H H H NO OPERATION (NOP/Continue previous operation)
L L H H ACTIVE (Select and activate row)
Idle L L L H AUTO REFRESH 7
LLLLLOAD MODE REGISTER 7
L L H L PRECHARGE 11
L H L H READ (Select column and start READ burst) 10
Row Active L H L L WRITE (Select column and start WRITE burst) 10
L L H L PRECHARGE (Deactivate row in bank or banks) 8
Read L H L H READ (Select column and start new READ burst) 10
(Auto L H L L WRITE (Select column and start WRITE burst) 10
Precharge L L H L PRECHARGE (Truncate READ burst, start PRECHARGE) 8
Disabled) L H H L BURST TERMINATE 9
Write L H L H READ (Select column and start READ burst) 10
(Auto L H L L WRITE (Select column and start new WRITE burst) 10
Precharge L L H L PRECHARGE (Truncate WRITE burst, start PRECHARGE) 8
Disabled) L H H L BURST TERMINATE 9
NOTE: 1. This table applies when CKE
n-1
was HIGH and CKEn is HIGH (see Truth Table 2) and after tXSR has been
met (if the previous state was self refresh).
2. This table is bank-specific, except where noted, i.e., the current state is for a specific bank and the commands shown are those allowed to be issued to that bank when in that state. Exceptions are covered in the notes below.
3. Current state definitions:
Idle: The bank has been precharged, and tRP has been met.
Row Active: A row in the bank has been activated, and tRCD has been met. No data bursts/
accesses and no register accesses are in progress.
Read: A READ burst has been initiated, with auto precharge disabled, and has not yet
terminated or been terminated.
Write: A WRITE burst has been initiated, with auto precharge disabled, and has not yet
terminated or been terminated.
4. The following states must not be interrupted by a command issued to the same bank. COMMAND INHIBIT or NOP commands, or allowable commands to the other bank should be issued on any clock edge occurring during these states. Allowable commands to the other bank are determined by its current state and Truth Table 3, and according to Truth Table 4.
Precharging: Starts with registration of a PRECHARGE command and ends when tRP is met.
Once tRP is met, the bank will be in the idle state.
Row Activating: Starts with registration of an ACTIVE command and ends when tRCD is met. Once
t
RCD is met, the bank will be in the row active state.
Read w/Auto
Precharge Enabled: Starts with registration of a READ command with auto precharge enabled and
ends when tRP has been met. Once tRP is met, the bank will be in the idle state.
27
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
NOTE (continued):
Write w/Auto
Precharge Enabled: Starts with registration of a WRITE command with auto precharge enabled and
ends when tRP has been met. Once tRP is met, the bank will be in the idle state.
5. The following states must not be interrupted by any executable command; COMMAND INHIBIT or NOP commands must be applied on each positive clock edge during these states.
Refreshing: Starts with registration of an AUTO REFRESH command and ends when tRC is met.
Once tRC is met, the SDRAM will be in the all banks idle state.
Accessing Mode
Register: Starts with registration of a LOAD MODE REGISTER command and ends when
t
MRD has been met. Once tMRD is met, the SDRAM will be in the all banks idle
state.
Precharging All: Starts with registration of a PRECHARGE ALL command and ends when
t
RP is met.
Once tRP is met, all banks will be in the idle state.
6. All states and sequences not shown are illegal or reserved.
7. Not bank-specific; requires that all banks are idle.
8. May or may not be bank-specific; if all banks are to be precharged, all must be in a valid state for precharging.
9. Not bank-specific; BURST TERMINATE affects the most recent READ or WRITE burst, regardless of bank.
10. READs or WRITEs listed in the Command (Action) column include READs or WRITEs with auto precharge enabled and READs or WRITEs with auto precharge disabled.
11. Does not affect the state of the bank and acts as a NOP to that bank.
28
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
TRUTH TABLE 4 – CURRENT STATE BANK n, COMMAND TO BANK m
(Notes: 1-6; notes appear below and on next page)
CURRENT STATE CS# RAS# CAS# WE# COMMAND (ACTION) NOTES
Any H X X X COMMAND INHIBIT (NOP/Continue previous operation)
L H H H NO OPERATION (NOP/Continue previous operation)
Idle XXXXAny Command Otherwise Allowed to Bank m
Row L L H H ACTIVE (Select and activate row)
Activating, L H L H READ (Select column and start READ burst) 7
Active, or L H L L WRITE (Select column and start WRITE burst) 7
Precharging L L H L PRECHARGE
Read L L H H ACTIVE (Select and activate row)
(Auto L H L H READ (Select column and start new READ burst) 7, 10
Precharge L H L L WRITE (Select column and start WRITE burst) 7, 11
Disabled) L L H L PRECHARGE 9
Write L L H H ACTIVE (Select and activate row)
(Auto L H L H READ (Select column and start READ burst) 7, 12
Precharge L H L L WRITE (Select column and start new WRITE burst) 7, 13
Disabled) L L H L PRECHARGE 9
Read L L H H ACTIVE (Select and activate row)
(With Auto L H L H READ (Select column and start new READ burst) 7, 8, 14
Precharge) L H L L WRITE (Select column and start WRITE burst) 7, 8, 15
L L H L PRECHARGE 9
Write L L H H ACTIVE (Select and activate row)
(With Auto L H L H READ (Select column and start READ burst) 7, 8, 16
Precharge) L H L L WRITE (Select column and start new WRITE burst) 7, 8, 17
L L H L PRECHARGE 9
NOTE: 1. This table applies when CKE
n-1
was HIGH and CKEn is HIGH (see Truth Table 2) and after tXSR has been
met (if the previous state was self refresh).
2. This table describes alternate bank operation, except where noted; i.e., the current state is for bank n and the commands shown are those allowed to be issued to bank m (assuming that bank m is in such a state that the given command is allowable). Exceptions are covered in the notes below.
3. Current state definitions:
Idle: The bank has been precharged, and tRP has been met.
Row Active: A row in the bank has been activated, and tRCD has been met. No data bursts/
accesses and no register accesses are in progress.
Read: A READ burst has been initiated, with auto precharge disabled, and has not yet
terminated or been terminated.
Write: A WRITE burst has been initiated, with auto precharge disabled, and has not yet
terminated or been terminated.
Read w/Auto
Precharge Enabled: Starts with registration of a READ command with auto precharge enabled, and
ends when tRP has been met. Once tRP is met, the bank will be in the idle state.
29
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
NOTE (continued):
4. AUTO REFRESH, SELF REFRESH, and LOAD MODE REGISTER commands may only be issued when all banks are idle.
5. A BURST TERMINATE command cannot be issued to another bank; it applies to the bank represented by the current state only.
6. All states and sequences not shown are illegal or reserved.
7. READs or WRITEs to bank m listed in the Command (Action) column include READs or WRITEs with auto precharge enabled and READs or WRITEs with auto precharge disabled.
8. CONCURRENT AUTO PRECHARGE: Bank n will initiate the auto precharge command when its burst has been interrupted by bank m’s burst.
9. Burst in bank n continues as initiated.
10. For a READ without auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will interrupt the READ on bank n, CAS latency later (Figure 7).
11. For a READ without auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will interrupt the READ on bank n when registered (Figures 9 and 10). DQM should be used one clock prior to the WRITE command to prevent bus contention.
12. For a WRITE without auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will interrupt the WRITE on bank n when registered (Figure 17), with the data-out appearing CAS latency later. The last valid WRITE to bank n will be data-in registered one clock prior to the READ to bank m.
13. For a WRITE without auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will interrupt the WRITE on bank n when registered (Figure 15). The last valid WRITE to bank n will be data-in registered one clock prior to the READ to bank m.
14. For a READ with auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will interrupt the READ on bank n, CAS latency later. The PRECHARGE to bank n will begin when the READ to bank m is registered (Figure 24).
15. For a READ with auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will interrupt the READ on bank n when registered. DQM should be used two clocks prior to the WRITE command to prevent bus contention. The PRECHARGE to bank n will begin when the WRITE to bank m is registered (Figure 25).
16. For a WRITE with auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will interrupt the WRITE on bank n when registered, with the data-out appearing CAS latency later. The PRECHARGE to bank n will begin after tWR is met, where tWR begins when the READ to bank m is registered. The last valid WRITE to bank n will be data-in registered one clock prior to the READ to bank m (Figure 26).
17. For a WRITE with auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will interrupt the WRITE on bank n when registered. The PRECHARGE to bank n will begin after tWR is met, where tWR begins when the WRITE to bank m is registered. The last valid WRITE to bank n will be data registered one clock prior to the WRITE to bank m (Figure 27).
30
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
ABSOLUTE MAXIMUM RATINGS*
Voltage on VDD, VDDQ Supply
Relative to VSS .............................................. -1V to +4.6V
Voltage on Inputs, NC or I/O Pins
Relative to V
SS .............................................. -1V to +4.6V
Operating Temperature, T
A
............................
0°C to +70°C
Extended Temperature .......................... -40°C to +85°C
Storage Temperature (plastic) ............ -55°C to +150°C
Power Dissipation ........................................................ 1W
*Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only, and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability.
DC ELECTRICAL CHARACTERISTICS AND OPERATING CONDITIONS
(Notes: 1, 6, 27; notes appear on page 35) (VDD, VDDQ = +3.3V ±0.3V)
PARAMETER/CONDITION SYMBOL MIN MAX UNITS NOTES
SUPPLY VOLTAGE VDD, VDDQ 3 3.6 V 27
INPUT HIGH VOLTAGE: Logic 1; All inputs VIH 2VDD + 0.3 V 22
INPUT LOW VOLTAGE: Logic 0; All inputs VIL -0.3 0.8 V 22
INPUT LEAKAGE CURRENT: Any input 0V ≤ VIN ≤ VDD II -5 5 µA (All other pins not under test = 0V)
OUTPUT LEAKAGE CURRENT: DQs are disabled; 0V ≤ VOUT ≤ VDDQIOZ -5 5 µA
OUTPUT LEVELS: VOH 2.4 V Output High Voltage (IOUT = -4mA) Output Low Voltage (IOUT = 4mA) VOL –0.4V
31
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
IDD SPECIFICATIONS AND CONDITIONS
(Notes: 1, 6, 11, 13, 27; notes appear on page 35) (VDD, VDDQ = +3.3V ±0.3V)
PARAMETER/CONDITION SYMBOL -5 -55 UNITS NOTES
OPERATING CURRENT: Active Mode; IDD1 200 190 m A 3, 18, Burst = 2; READ or WRITE; tRC = tRC (MIN); 19, 26 CAS latency = 3
STANDBY CURRENT: Power-Down Mode; IDD2 22mA CKE = LOW; All banks idle
STANDBY CURRENT: Active Mode; CS# = HIGH; IDD3 80 70 mA 3, 12, CKE = HIGH; All banks active after tRCD met;
19, 26
No accesses in progress
OPERATING CURRENT: Burst Mode; Continuous burst; IDD4 280 260 mA 3, 18, READ or WRITE; All banks active, 19, 26 CAS latency = 3
AUTO REFRESH CURRENT:
t
RFC = tRFC (MIN) IDD5 225 225 mA 3, 12,
CAS latency = 3; CKE, CS# = HIGH 18, 19,
26, 29
SELF REFRESH CURRENT: CKE 0.2V IDD6 22mA4
MAX
IDD SPECIFICATIONS AND CONDITIONS
(Notes: 1, 6, 11, 13, 27; notes appear on page 35) (VDD, VDDQ = +3.3V ±0.3V)
PARAMETER/CONDITION SYMBOL -6 -7 UNITS NOTES
OPERATING CURRENT: Active Mode; IDD1 150 130 mA 3, 18, Burst = 2; READ or WRITE; tRC = tRC (MIN); 19, 26 CAS latency = 3
STANDBY CURRENT: Power-Down Mode; IDD2 22mA CKE = LOW; All banks idle
STANDBY CURRENT: Active Mode; CS# = HIGH; I
DD3 60 50 mA 3, 12,
CKE = HIGH; All banks active after
t
RCD met; 19, 26
No accesses in progress
OPERATING CURRENT: Burst Mode; Continuous burst; IDD4 180 160 mA 3, 18, READ or WRITE; All banks active, 19, 26 CAS latency = 3
AUTO REFRESH CURRENT:
t
RFC = tRFC (MIN) IDD5 225 225 mA 3, 12,
CAS latency = 3; CKE, CS# = HIGH 18, 19,
26, 29
SELF REFRESH CURRENT: CKE 0.2V IDD6 22mA4
MAX
32
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
ELECTRICAL CHARACTERISTICS AND RECOMMENDED AC OPERATING CONDITIONS
(Notes: 5, 6, 8, 9, 11; notes appear on page 35)
AC CHARACTERISTICS -5 -55 PARAMETER SYMBOL MIN MAX MIN MAX UNITS NOTES
Access time from CLK CL = 3
t
AC (3) 4.5 5 ns
(pos. edge) CL = 2
t
AC (2) - - ns
CL = 1
t
AC (1) - - ns
Address hold time
t
AH 1 1 ns
Address setup time
t
AS 1.5 1.5 ns
CLK high-level width
t
CH 2 2 ns
CLK low-level width
t
CL 2 2 ns
Clock cycle time CL = 3
t
CK (3) 5 5.5 ns 23
CL = 2
t
CK (2) - - ns 23
CL = 1
t
CK (1) - - ns 23
CKE hold time
t
CKH 1 1 ns
CKE setup time
t
CKS 1.5 1.5 ns
CS#, RAS#, CAS#, WE#, DQM hold time
t
CMH 1 1 ns
CS#, RAS#, CAS#, WE#, DQM setup time
t
CMS 1.5 1.5 ns
Data-in hold time
t
DH 1 1 ns
Data-in setup time
t
DS 1.5 1.5 ns
Data-out high-impedance time CL = 3
t
HZ (3) 4.5 5 ns 10
CL = 2
t
HZ (2) - - ns 10
CL = 1
t
HZ (1) - - ns 10
Data-out low-impedance time
t
LZ 1 1 ns
Data-out hold time
t
OH 1.5 2 ns
ACTIVE to PRECHARGE command
t
RAS 38.7 120k 38.7 120k ns
ACTIVE to ACTIVE command period
t
RC 55 55 ns
AUTO REFRESH period
t
RFC 60 60 ns
ACTIVE to READ or WRITE delay
t
RCD 15 16.5 ns
Refresh period (4,096 rows)
t
REF 64 64 ms
PRECHARGE command period
t
RP 15 16.5 ns
ACTIVE bank a to ACTIVE bank b command
t
RRD 10 11 ns 25
Transition time
t
T 0.3 1.2 0.3 1.2 ns 7
WRITE recovery time
t
WR 2 2
t
CK 24
Exit SELF REFRESH to ACTIVE command
t
XSR 55 55 ns 20
CAPACITANCE
(Note: 2; notes appear on page 35)
PARAMETER SYMBOL MIN MAX UNITS
Input Capacitance: CLK CI1 2.5 4.0 p F
Input Capacitance: All other input-only pins CI2 2.5 4.0 pF
Input/Output Capacitance: DQs CIO 4.0 6.5 pF
33
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
ELECTRICAL CHARACTERISTICS AND RECOMMENDED AC OPERATING CONDITIONS
(Notes: 5, 6, 8, 9, 11; notes appear on page 35)
AC CHARACTERISTICS -6 -7 PARAMETER SYMBOL MIN MAX MIN MAX UNITS NOTES
Access time from CLK CL = 3
t
AC (3) 5. 5 5.5 ns
(pos. edge) CL = 2
t
AC (2) 7. 5 8 ns
CL = 1
t
AC (1) 17 17 ns
Address hold time
t
AH 1 1 ns
Address setup time
t
AS 1.5 2 ns
CLK high-level width
t
CH 2.5 2.75 ns
CLK low-level width
t
CL 2.5 2.75 ns
Clock cycle time CL = 3
t
CK (3) 6 7 ns 23
CL = 2
t
CK (2) 10 10 ns 23
CL = 1
t
CK (1) 20 20 ns 23
CKE hold time
t
CKH 1 1 ns
CKE setup time
t
CKS 1.5 2 ns
CS#, RAS#, CAS#, WE#, DQM hold time
t
CMH 1 1 ns
CS#, RAS#, CAS#, WE#, DQM setup time
t
CMS 1.5 2 ns
Data-in hold time
t
DH 1 1 ns
Data-in setup time
t
DS 1.5 2 ns
Data-out high-impedance time CL = 3
t
HZ (3) 5.5 5.5 ns 10
CL = 2
t
HZ (2) 7.5 8 ns 10
CL = 1
t
HZ (1) 17 17 ns 10
Data-out low-impedance time
t
LZ 1 1 ns
Data-out hold time
t
OH 2 2.5 ns
ACTIVE to PRECHARGE command
t
RAS 42 120k 42 120k ns
ACTIVE to ACTIVE command period
t
RC 60 70 ns
AUTO REFRESH period
t
RFC 60 70 ns
ACTIVE to READ or WRITE delay
t
RCD 18 20 ns
Refresh period (4,096 rows)
t
REF 64 64 ms
PRECHARGE command period
t
RP 18 20 ns
ACTIVE bank a to ACTIVE bank b command
t
RRD 12 14 ns 25
Transition time
t
T 0.3 1.2 0.3 1.2 ns 7
WRITE recovery time
t
WR 1CLK+ 1CLK+
t
CK 24
6ns 7ns
12ns 14ns ns 28
Exit SELF REFRESH to ACTIVE command
t
XSR 70 70 ns 20
34
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
AC FUNCTIONAL CHARACTERISTICS
(Notes: 5, 6, 7, 8, 9, 11; notes appear on page 35)
PARAMETER SYMBOL - 5 -5 5 -6 -7 UNITS NOTES
READ/WRITE command to READ/WRITE command
t
CCD 1111tCK 17
CKE to clock disable or power-down entry mode
t
CKED 1111tCK 14
CKE to clock enable or power-down exit setup mode
t
PED 1111tCK 14
DQM to input data delay
t
DQD 0000tCK 17
DQM to data mask during WRITEs
t
DQM 0000tCK 17
DQM to data high-impedance during READs
t
DQZ 2222tCK 17
WRITE command to input data delay
t
DWD 0000tCK 17
Data-in to ACTIVE command CL = 3
t
DAL (3) 5555tCK 15, 21
CL = 2
t
DAL (2) - - 4 4
t
CK 15, 21
CL = 1
t
DAL (1) - - 3 3
t
CK 15, 21
Data-in to PRECHARGE command
t
DPL 2222tCK 16, 21
Last data-in to burst STOP command
t
BDL 1111tCK 17
Last data-in to new READ/WRITE command
t
CDL 1111tCK 17
Last data-in to PRECHARGE command
t
RDL 2222tCK 16, 21
LOAD MODE REGISTER command to ACTIVE or REFRESH command
t
MRD 2222tCK 26
Data-out to high-impedance from PRECHARGE command CL = 3
t
ROH (3) 3333tCK 17
CL = 2
t
ROH (2) - - 2 2
t
CK 17
CL = 1
t
ROH (1) - - 1
t
CK 17
35
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
13. IDD specifications are tested after the device is prop­erly initialized.
14. Timing actually specified by tCKS; clock(s) speci­fied as a reference only at minimum cycle rate.
15. Timing actually specified by tWR plus tRP; clock(s) specified as a reference only at minimum cycle rate.
16. Timing actually specified by tWR.
17. Required clocks are specified by JEDEC function­ality and are not dependent on any timing param­eter.
18. The IDD current will decrease as the CAS latency is reduced. This is due to the fact that the maximum cycle rate is slower as the CAS latency is reduced.
19. Address transitions average one transition every two clocks.
20. CLK must be toggled a minimum of two times dur­ing this period.
21. Based on tCK = 143 MHz for -7, 166 MHz for -6, 183 MHz for -55, and 200 MHz for -5.
22. VIH overshoot: VIH(MAX) = VDDQ + 1.2V for a pulse width 3ns, and the pulse width cannot be greater than one third of the cycle rate. VIL undershoot: VIL(MIN) = -1.2V for a pulse width 3ns, and the pulse width cannot be greater than one third of the cycle rate.
23. The clock frequency must remain constant during access or precharge states (READ, WRITE, includ­ing tWR, and PRECHARGE commands). CKE may be used to reduce the data rate.
24. Auto precharge mode only.
25. JEDEC and PC100 specify three clocks.
26.tCK = 7ns for -7, 6ns for -6, 5.5ns for -5.5, and 5ns for -5.
27. VDD(MIN) = 3.135V for -6, -55, and -5 speed grades.
28. Check factory for availability of specially screened devices having tWR = 10ns. tWR = 1 tCK for 100 MHz and slower (tCK = 10ns and higher) in manual precharge.
NOTES
1. All voltages referenced to VSS.
2. This parameter is sampled. VDD, VDDQ = +3.3V; f = 1 MHz, TA = 25°C; pin under test biased at 1.4V. AC can range from 0pF to 6pF.
3. IDD is dependent on output loading and cycle rates. Specified values are obtained with minimum cycle time and the outputs open.
4. Enables on-chip refresh and address counters.
5. The minimum specifications are used only to indi­cate cycle time at which proper operation over the full temperature range (0°C ≤ TA +70°C and
-40°C TA +85°C for IT parts) is ensured.
6. An initial pause of 100µs is required after power­up, followed by two AUTO REFRESH commands, before proper device operation is ensured. (VDD and VDDQ must be powered up simultaneously. VSS and VSSQ must be at same potential.) The two AUTO REFRESH command wake-ups should be repeated any time the tREF refresh requirement is exceeded.
7. AC characteristics assume tT = 1ns.
8. In addition to meeting the transition rate specifi­cation, the clock and CKE must transit between VIH and VIL (or between VIL and VIH) in a monotonic manner.
9. Outputs measured at 1.5V with equivalent load:
10.tHZ defines the time at which the output achieves the open circuit condition; it is not a reference to VOH or VOL. The last valid data element will meet
t
OH before going High-Z.
11. AC timing and IDD tests have VIL = .25 and VIH = 2.75, with timing referenced to 1.5V crossover point.
12. Other input signals are allowed to transition no more than once in any two-clock period and are otherwise at valid VIH or VIL levels.
Q
30p
F
36
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
INITIALIZE AND LOAD MODE REGISTER
*CAS latency indicated in parentheses.
NOTE: 1. The Mode Register may be loaded prior to the AUTO REFRESH cycles if desired.
2. Outputs are guaranteed High-Z after command is issued.
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
CKH 1 1 1 ns
t
CKS 1.5 1.5 2 ns
t
CMH111ns
t
CM S 1.5 1.5 2 n s
t
MRD222tCK
t
R FC 60 60 70 n s
t
RP 15 18 20 n s
TIMING PARAMETERS
-5 -6 -7
SYMBOL* MIN MAX M IN M AX MIN MAX UNITS
t
AH111ns
t
AS 1.5 1.5 2 n s
t
CH 2 2.5 2.75 ns
t
CL 2 2.5 2.75 n s
t
CLK (3) 5 6 7 ns
t
CLK (2) 10 10 ns
t
CLK (1) 20 20 ns
t
CH
t
CL
t
CK
CKE
CLK
COMMAND
DQ
BA0, BA1
BANK
t
RFC
t
MRD
t
RFC
AUTO REFRESH
AUTO REFRESH
Program Mode Register
1, 2, 5
t
CMH
t
CMS
Precharge all banks
()(
)
()(
)
()(
)
()(
)
t
RP
()(
)
()(
)
t
CKS
Power-up: V
DD
and
CK stable
T = 100µs
(MIN)
PRECHARGE NOP
AUTO
REFRESH
NOP
LOAD MODE
REGISTER
ACTIVENOP NOPNOP
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
AUTO
REFRESH
ALL
BANKS
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
High-Z
t
CKH
()(
)
()(
)
DQM 0-3
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
NOP
()(
)
()(
)
t
CMH
t
CMS
t
CMH
t
CMS
A0-A9
ROW
t
AH
t
AS
CODE
t
AH
t
AS
CODE
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
A10
ROW
t
AH
t
AS
CODE
()(
)
()(
)
()(
)
()(
)
ALL BANKS
SINGLE BANK
()(
)
()(
)
()(
)
()(
)
DON’T CARE
UNDEFINED
T0 T1 Tn + 1 To + 1 Tp + 1 Tp + 2 Tp + 3
37
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
NOTE: 1. Violating refresh requirements during power-down may result in a loss of data.
POWER-DOWN MODE
1
*CAS latency indicated in parentheses.
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
CK (1) 20 20 ns
t
CKH 1 1 1 ns
t
CKS 1.5 1.5 2 ns
t
CMH111ns
t
CM S 1.5 1.5 2 n s
TIMING PARAMETERS
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
AH111ns
t
AS 1.5 1.5 2 n s
t
CH 2 2.5 2.75 ns
t
CL 2 2.5 2.75 n s
t
CK (3) 5 6 7 ns
t
CK (2) 10 10 ns
t
CH
t
CL
t
CK
Two clock cycles
CKE
CLK
DQ
All banks idle, enter power-down mode
Precharge all
active banks
Input buffers gated off while in
power-down mode
Exit power-down mode
()(
)
()(
)
t
CKS
t
CKS
COMMAND
t
CMH
t
CMS
PRECHARGE NOP NOP ACTIVENOP
()(
)
()(
)
All banks idle
BA0, BA1
BANK
BANK(S)
()(
)
()(
)
High-Z
t
AH
t
AS
t
CKH
t
CKS
DQM 0-3
()(
)
()(
)
()(
)
()(
)
A0-A9
ROW
()(
)
()(
)
ALL BANKS
SINGLE BANK
A10
ROW
()(
)
()(
)
T0 T1 T2 Tn + 1 Tn + 2
DON’T CARE
UNDEFINED
38
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
CLOCK SUSPEND MODE
1
NOTE: 1. For this example, the burst length = 2, the CAS latency = 3, and auto precharge is disabled.
2. A8 and A9 = “Don’t Care.”
*CAS latency indicated in parentheses.
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
CKS 1.5 1.5 2 ns
t
CMH111ns
t
CM S 1.5 1.5 2 n s
t
DH111ns
t
DS 1.5 1.5 2 n s
t
HZ (3 ) 4.5 5.5 5.5 ns
t
HZ (2) 7.5 8 ns
t
HZ (1) 17 17 ns
t
LZ111ns
t
OH 1.5 2 2.5 ns
TIMING PARAMETERS
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
AC (3) 4.5 5.5 5.5 ns
t
AC (2) 7.5 8 ns
t
AC (1) 17 17 ns
t
AH111ns
t
AS 1.5 1.5 2 n s
t
CH 2 2.5 2.75 ns
t
CL 2 2.5 2.75 n s
t
CK (3) 5 6 7 ns
t
CK (2) 10 10 ns
t
CK (1) 20 20 ns
t
CKH 1 1 1 ns
t
CH
t
CL
t
CK
t
AC
t
LZ
DQM0-3
CLK
DQ
A10
t
OH
D
OUT
m
t
AH
t
AS
t
AH
t
AS
t
AH
t
AS
BANK
t
DH
D
OUT
e
t
AC
t
HZ
D
OUT
m + 1
COMMAND
t
CMH
t
CMS
NOPNOP NOP NOPNOPREAD WRITE
DON’T CARE
UNDEFINED
CKE
t
CKStCKH
BANK
COLUMN m
t
DS
D
OUT
e + 1
NOP
t
CKH
t
CKS
t
CMH
t
CMS
2
COLUMN e
2
T0 T1 T2 T3 T4 T5 T6 T7 T8 T9
BA0, BA1
A0-A9
39
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
AUTO REFRESH MODE
*CAS latency indicated in parentheses.
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
CKH 1 1 1 ns
t
CKS 1.5 1.5 2 ns
t
CMH111ns
t
CM S 1.5 1.5 2 n s
t
R FC 60 60 70 n s
t
RP 15 18 20 n s
TIMING PARAMETERS
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
AH111ns
t
AS 1.5 1.5 2 n s
t
CH 2 2.5 2.75 ns
t
CL 2 2.5 2.75 n s
t
CK (3) 5 6 7 ns
t
CK (2) 10 10 ns
t
CK (1) 20 20 ns
UNDEFINEDDON’T CARE
t
CH
t
CL
t
CK
CKE
CLK
DQ
t
RFC
()(
)
()(
)
()(
)
t
RP
()(
)
()(
)
()(
)
()(
)
COMMAND
t
CMH
t
CMS
NOPNOP
()(
)
()(
)
BANK
ACTIVE
AUTO
REFRESH
()(
)
()(
)
NOPNOPPRECHARGE
Precharge all
active banks
AUTO
REFRESH
t
RFC
High-Z
BANK(S)
()(
)
()(
)
()(
)
()(
)
t
AH
t
AS
t
CKH
t
CKS
()(
)
NOP
()(
)
()(
)
()(
)
()(
)
ROW
()(
)
()(
)
ALL BANKS
SINGLE BANK
A10
ROW
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
T0 T1 T2 Tn + 1 To + 1
BA0, BA1
A0–A9
DQM 0–3
DON’T CARE
40
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
SELF REFRESH MODE
*CAS latency indicated in parentheses.
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
CKH 1 1 1 ns
t
CKS 1.5 1.5 2 ns
t
CMH111ns
t
CM S 1.5 1.5 2 n s
t
RAS 38.7 120,000 42 120,000 42 120,000 n s
t
RP 15 18 20 n s
t
XS R 55 70 70 n s
TIMING PARAMETERS
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
AH111ns
t
AS 1.5 1.5 2 n s
t
CH 2 2.5 2.75 ns
t
CL 2 2.5 2.75 n s
t
CK (3) 5 6 7 ns
t
CK (2) 10 10 ns
t
CK (1) 20 20 ns
t
CH
t
CL
t
CK
t
RP
CKE
CLK
DQ
Enter self refresh mode
Precharge all
active banks
t
XSR
CLK stable prior to exiting
self refresh mode
Exit self refresh mode
(Restart refresh time base)
()(
)
()(
)
()(
)
DON’T CARE
UNDEFINED
COMMAND
t
CMH
t
CMS
AUTO
REFRESH
PRECHARGE NOP NOP
BANK(S)
High-Z
t
CKS
AH
AS
AUTO
REFRESH
> t
RAS
t
CKH
t
CKS
tt
t
CKS
ALL BANKS
SINGLE BANK
A10
T0 T1 T2 Tn + 1 To + 1 To + 2
BA0, BA1
DQM 0-3
A0-A9
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
41
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
SINGLE READ
1
*CAS latency indicated in parentheses.
ALL BANKS
t
CH
t
CL
t
CK
t
AC
t
LZ
t
RP
t
RAS
t
RCD
CAS Latency
t
RC
DQM /
DQML, DQMH
CKE
CLK
A0-A9
DQ
BA0, BA1
A10
t
OH
DOUT
m
t
CMH
t
CMS
t
AH
t
AS
t
AH
t
AS
t
AH
t
AS
ROW
ROW
BANK BANK BANK
ROW
ROW
BANK
t
HZ
COMMAND
t
CMH
t
CMS
PRECHARGEACTIVE NOP READ NOP ACTIVE
DISABLE AUTO PRECHARGE
SINGLE BANK
t
CKH
t
CKS
COLUMN
m
2
T0 T1 T2 T4T3 T5
DON’T CARE
NOTE: 1. For this example, the burst length = 1, the CAS latency = 2, and the READ burst is followed by a “manual” PRECHARGE.
2. A8, A9 = “Don’t Care.”
TIMING PARAMETERS
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
AC (3) 4.5 5.5 5.5 ns
t
AC (2) - 7.5 8 ns
t
AC (1) - 17 17 ns
t
AH111ns
t
AS 1.5 1.5 2 n s
t
CH 2 2.5 2.75 ns
t
CL 2 2.5 2.75 n s
t
CK (3) 5 6 7 ns
t
CK (2) - 10 10 ns
t
CK (1) - 20 20 ns
t
CKH 1 1 1 ns
t
CKS 1.5 1.5 2 ns
t
CMH111ns
t
CM S 1.5 1.5 2 n s
t
HZ (3 ) 4.5 5.5 5.5 ns
t
HZ (2) - 7.5 8 ns
t
HZ (1) - 17 17 ns
t
LZ111ns
t
OH 1.5 2 2.5 ns
t
RAS 38.7 120,000 42 120,000 42 120,000 n s
t
RC 55 60 70 n s
t
R CD 15 18 20 n s
t
RP 15 18 20 n s
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
42
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
READ – WITHOUT AUTO PRECHARGE
1
NOTE: 1. For this example, the burst length = 4, the CAS latency = 2, and the READ burst is followed by a “manual” PRECHARGE.
2. A8 and A9 = “Don’t Care.”
*CAS latency indicated in parentheses.
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
CMH111ns
t
CM S 1.5 1.5 2 n s
t
HZ (3 ) 4.5 5.5 5.5 n s
t
HZ (2) - 7.5 8 ns
t
HZ (1) - 17 17 ns
t
LZ111ns
t
OH 1.5 2 2.5 ns
t
RAS 38.7 120,000 42 120,000 42 120,000 n s
t
RC 55 60 70 n s
t
R CD 15 18 20 n s
t
RP 15 18 20 n s
TIMING PARAMETERS
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
AC (3) 4.5 5.5 5.5 n s
t
AC (2) - 7.5 8 ns
t
AC (1) - 17 17 ns
t
AH111ns
t
AS 1.5 1.5 2 n s
t
CH 2 2.5 2.75 ns
t
CL 2 2.5 2.75 n s
t
CK (3) 5 6 7 ns
t
CK (2) - 10 10 ns
t
CK (1) - 20 20 ns
t
CKH 1 1 1 ns
t
CKS 1.5 1.5 2 ns
ALL BANKS
t
CH
t
CL
t
CK
t
AC
t
LZ
t
RP
t
RAS
t
RCD
CAS Latency
t
RC
CKE
CLK
DQ
A10
t
OH
D
OUT
m
t
CMH
t
CMS
t
AH
t
AS
t
AH
t
AS
t
AH
t
AS
ROW
ROW
BANK BANK BANK
ROW
ROW
BANK
t
HZ
t
OH
D
OUT
m + 3
t
AC
t
OH
t
AC
t
OH
t
AC
D
OUT
m + 2D
OUT
m + 1
COMMAND
t
CMH
t
CMS
PRECHARGENOPNOP NOPACTIVE NOP READ NOP ACTIVE
DISABLE AUTO PRECHARGE
SINGLE BANK
DON’T CARE
UNDEFINED
t
CKH
t
CKS
COLUMN m
2
T0 T1 T2 T4T3 T5 T6 T7 T8
BA0, BA1
DQM 0-3
A0-A9
43
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
READ – WITH AUTO PRECHARGE
1
DON’T CARE
UNDEFINED
ENABLE AUTO PRECHARGE
t
CH
t
CL
t
CK
t
AC
t
LZ
t
RP
t
RAS
t
RCD
CAS Latency
t
RC
CKE
CLK
DQ
A10
t
OH
D
OUT
m
t
CMH
t
CMS
t
AH
t
AS
t
AH
t
AS
t
AH
t
AS
ROW
ROW
BANK
BANK
ROW
ROW
BANK
t
HZ
t
OH
D
OUT
m + 3
t
AC
t
OH
t
AC
t
OH
t
AC
D
OUT
m + 2D
OUT
m + 1
COMMAND
t
CMH
t
CMS
NOPNOP NOPACTIVE NOP READ NOP ACTIVENOP
t
CKH
t
CKS
COLUMN m
2
T0 T1 T2 T4T3 T5 T6 T7 T8
BA0, BA1
DQM 0-3
A0-A9
NOTE: 1. For this example, the burst length = 4, and the CAS latency = 2.
2. A8 and A9 = “Don’t Care.”
*CAS latency indicated in parentheses.
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
CMH111ns
t
CM S 1.5 1.5 2 n s
t
HZ (3 ) 4.5 5.5 5.5 n s
t
HZ (2) - 7.5 8 ns
t
HZ (1) - 17 17 ns
t
LZ111ns
t
OH 1.5 2 2.5 ns
t
RAS 38.7 120,000 42 120,000 42 120,000 n s
t
RC 55 60 70 n s
t
R CD 15 18 20 n s
t
RP 15 18 20 n s
TIMING PARAMETERS
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
AC (3) 4.5 5.5 5.5 n s
t
AC (2) - 7.5 8 ns
t
AC (1) - 17 17 ns
t
AH111ns
t
AS 1.5 1.5 2 n s
t
CH 2 2.5 2.75 ns
t
CL 2 2.5 2.75 n s
t
CK (3) 5 6 7 ns
t
CK (2) - 10 10 ns
t
CK (1) - 20 20 ns
t
CKH 1 1 1 ns
t
CKS 1.5 1.5 2 ns
44
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
ALTERNATING BANK READ ACCESSES
1
NOTE: 1. For this example, the burst length = 4, and the CAS latency = 2.
2. A8 and A9 = “Don’t Care.”
*CAS latency indicated in parentheses.
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
CKS 1.5 1.5 2 ns
t
CMH111ns
t
CM S 1.5 1.5 2 n s
t
LZ111ns
t
OH 1.5 2 2.5 ns
t
RAS 38.7 120,000 42 120,000 42 120,000 n s
t
RC 55 60 70 n s
t
R CD 15 18 20 n s
t
RP 15 18 20 n s
t
R RD 10 12 14 n s
TIMING PARAMETERS
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
AC (3) 4.5 5.5 5.5 n s
t
AC (2) - 7.5 8 ns
t
AC (1) - 17 17 ns
t
AH111ns
t
AS 1.5 1.5 2 n s
t
CH 2 2.5 2.75 ns
t
CL 2 2.5 2.75 n s
t
CK (3) 5 6 7 ns
t
CK (2) - 10 10 ns
t
CK (1) - 20 20 ns
t
CKH 1.5 1 1 ns
DON’T CARE
UNDEFINED
ENABLE AUTO PRECHARGE
t
CH
t
CL
t
CK
t
AC
t
LZ
CLK
DQ
A10
t
OH
D
OUT
m
t
CMH
t
CMS
t
AH
t
AS
t
AH
t
AS
t
AH
t
AS
ROW
ROW
ROW
ROW
t
OH
D
OUT
m + 3
t
AC
t
OH
t
AC
t
OH
t
AC
D
OUT
m + 2D
OUT
m + 1
COMMAND
t
CMH
t
CMS
NOP NOPACTIVE NOP READ NOP ACTIVE
t
OH
D
OUT
b
t
AC
t
AC
READ
ENABLE AUTO PRECHARGE
ROW
ACTIVE
ROW
BANK 0 BANK 0 BANK 4 BANK 4
BANK 0
CKE
t
CKH
t
CKS
COLUMN m
2
COLUMN b
2
T0 T1 T2 T4T3 T5 T6 T7 T8
t
RP - BANK 0
t
RAS - BANK 0
t
RCD - BANK 0
t
RCD - BANK 0
CAS Latency - BANK 0
t
RCD - BANK 4
CAS Latency - BANK 4
t
t
RC - BANK 0
RRD
BA0, BA1
DQM 0-3
A0-A9
45
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
READ – FULL-PAGE BURST
1
NOTE: 1. For this example, the CAS latency = 2.
2. A8 and A9 = “Don’t Care.”
3. Page left open; no tRP.
*CAS latency indicated in parentheses.
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
CKH 1 1 1 ns
t
CKS 1.5 1.5 2 ns
t
CMH111ns
t
CM S 1.5 1.5 2 n s
t
HZ (3) 4.5 5 5.5 ns
t
HZ (2) - 7.5 8 ns
t
HZ (1) - 17 17 ns
t
LZ111ns
t
OH 1.5 2 2.5 ns
t
R CD 15 18 20 n s
TIMING PARAMETERS
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
AC (3) 4.5 5.5 5.5 n s
t
AC (2) - 7.5 8 ns
t
AC (1) - 17 17 ns
t
AH111ns
t
AS 1.5 1.5 2 n s
t
CH 2 2.5 2.75 ns
t
CL 2 2.5 2.75 n s
t
CK (3) 5 6 7 ns
t
CK (2) - 10 10 ns
t
CK (1) - 20 20 ns
t
CH
t
CL
t
CK
t
AC
t
LZ
t
RCD
CAS Latency
CKE
CLK
DQ
A10
t
OH
Dout m
t
CMH
t
CMS
t
AH
t
AS
t
AH
t
AS
t
AC
t
OH
D
OUT
m+1
ROW
ROW
t
HZ
t
AC
t
OH
D
OUT
m+1
t
AC
t
OH
D
OUT
m+2
t
AC
t
OH
D
OUT
m-1
t
AC
t
OH
D
OUT
m
Full-page burst does not self-terminate.
Can use BURST TERMINATE command.
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
Full page completed
256 locations within same row
DON’T CARE
UNDEFINED
COMMAND
t
CMH
t
CMS
NOPNOP NOPACTIVE NOP READ NOP BURST TERMNOP NOP
()(
)
()(
)
NOP
()(
)
()(
)
t
AH
t
AS
BANK
()(
)
()(
)
BANK
t
CKH
t
CKS
()(
)
()(
)
()(
)
()(
)
COLUMN m
2
3
T0 T1 T2 T4T3 T5 T6 Tn + 1 Tn + 2 Tn + 3 Tn + 4
BA0, BA1
DQM 0-3
A0-A9
46
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
READ – DQM OPERATION
1
t
CH
t
CL
t
CK
t
RCD
CAS Latency
CKE
CLK
DQ
A10
t
CMS
ROW
BANK
ROW
BANK
DON’T CARE
UNDEFINED
t
AC
LZ
D
OUT
m
t
OH
D
OUT
m + 3D
OUT
m + 2
t
t
HZ
LZ
t
t
CMH
COMMAND
NOPNOP NOPACTIVE NOP READ NOPNOP NOP
t
HZ
t
AC
t
OH
t
AC
t
OH
t
AH
t
AS
t
CMS
t
CMH
t
AH
t
AS
t
AH
t
AS
t
CKH
t
CKS
ENABLE AUTO PRECHARGE
DISABLE AUTO PRECHARGE
COLUMN m
2
T0 T1 T2 T4T3 T5 T6 T7 T8
BA0, BA1
DQM 0-3
A0-A9
NOTE: 1. For this example, the CAS latency = 2.
2. A8 and A9 = “Don’t Care.”
*CAS latency indicated in parentheses.
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
CKH 1 1 1 ns
t
CKS 1.5 1.5 2 ns
t
CMH111ns
t
CM S 1.5 1.5 2 n s
t
HZ (3) 4.5 5 5.5 ns
t
HZ (2) - 7.5 8 ns
t
HZ (1) - 17 17 ns
t
LZ111ns
t
OH 1.5 2 2.5 ns
t
R CD 15 18 20 n s
TIMING PARAMETERS
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
AC (3) 4.6 5.5 5.5 n s
t
AC (2) - 7.5 8 ns
t
AC (1) - 17 17 ns
t
AH111ns
t
AS 1.5 1.5 2 n s
t
CH 2 2.5 2.75 ns
t
CL 2 2.5 2.75 n s
t
CK (3) 5 6 7 ns
t
CK (2) - 10 10 ns
t
CK (1) - 20 20 ns
47
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
SINGLE WRITE
TIMING PARAMETERS
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
AH111ns
t
AS 1.5 1.5 2 n s
t
CH 2 2.5 2.75 ns
t
CL 2 2.5 2.75 n s
t
CK (3) 5 6 7 ns
t
CK (2) 10 10 ns
t
CK (1) 20 20 ns
t
CKH 1 1 1 ns
t
CKS 1.5 1.5 2 ns
t
CMH111ns
t
CM S 1.5 1.5 2 n s
t
DH111ns
t
DS 1.5 1.5 2 n s
t
RAS 38.7 120,000 42 120,000 42 120,000 n s
t
RC 55 60 70 n s
t
R CD 15 18 20 n s
t
RP 15 18 20 n s
t
WR 2 tC K 12 14 n s
*CAS latency indicated in parentheses.
DON’T CARE
DISABLE AUTO PRECHARGE
ALL BANKS
t
CH
t
CL
t
CK
t
RP
t
RAS
t
RCD
t
RC
DQM /
DQML, DQMH
CKE
CLK
A0-A9
DQ
BA0, BA1
A10
t
CMH
t
CMS
t
AH
t
AS
ROW
ROW
BANK BANK BANK
ROW
ROW
BANK
t
WR
DIN m
t
DH
t
DS
COMMAND
t
CMH
t
CMS
ACTIVE NOP WRITE NOP PRECHARGE ACTIVE
t
AH
t
AS
t
AH
t
AS
SINGLE BANK
t
CKH
t
CKS
COLUMN m
3
2
T0 T1 T2 T4T3 T5 T6
NOP
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
NOTE: 1. For this example, the burst length = 4, and the WRITE burst is followed by a “manual” PRECHARGE.
2. 10ns is required between <DIN m> and the PRECHARGE command, regardless of frequency, to meet tWR.
3. A8, A9 = “Don’t Care.”
48
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
WRITE – WITHOUT AUTO PRECHARGE
1
NOTE: 1. For this example, the burst length = 4, and the WRITE burst is followed by a “manual” PRECHARGE.
2. Faster frequencies require two clocks (when tWR > tCK).
3. A8 and A9 = “Don’t Care.”
4.tWR of 1 CLK available if running 100 MHz or slower. Check factory for availability.
*CAS latency indicated in parentheses.
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
CMH111ns
t
CM S 1.5 1.5 2 n s
t
DH111ns
t
DS 1.5 1.5 2 n s
t
RAS 38.7 120,000 42 120,000 42 120,000 n s
t
RC 55 60 70 n s
t
R CD 15 18 20 n s
t
RP 15 18 20 n s
tWR4
2 tC K 12 14 n s
TIMING PARAMETERS
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
AH111ns
t
AS 1.5 1.5 2 n s
t
CH 2 2.5 2.75 ns
t
CL 2 2.5 2.75 n s
t
CK (3) 5 6 7 ns
t
CK (2) 10 10 ns
t
CK (1) 20 20 ns
t
CKH 1 1 1 ns
t
CKS 1.5 2 2 ns
DISABLE AUTO PRECHARGE
ALL BANKs
t
CH
t
CL
t
CK
t
RP
t
RAS
t
RCD
t
RC
CKE
CLK
DQ
A10
t
CMH
t
CMS
t
AH
t
AS
ROW
ROW
BANK BANK BANK
ROW
ROW
BANK
t
WR
DON’T CARE
DIN m
t
DH
t
DS
DIN m + 1 DIN m + 2 DIN m + 3
COMMAND
t
CMH
t
CMS
NOPNOP NOPACTIVE NOP WRITE NOPPRECHARGE ACTIVE
t
AH
t
AS
t
AH
t
AS
t
DH
t
DS
t
DH
t
DS
t
DH
t
DS
SINGLE BANK
t
CKH
t
CKS
COLUMN m
3
2
T0 T1 T2 T4T3 T5 T6 T7 T8
DQM 0-3
BA0, BA1
A0-A9
49
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
t
CMS 1.5 1.5 2 ns
t
DH111ns
t
DS 1.5 1.5 2 ns
t
RA S 38.7 120,000 42 120,000 42 120,000 ns
t
RC 55 60 70 n s
t
R C D 15 18 20 n s
t
RP 15 18 20 n s
t
WR 2 tCK 1 CLK+ 1 CLK+ ns
67
WRITE – WITH AUTO PRECHARGE
1
NOTE: 1. For this example, the burst length = 4.
2. Faster frequencies require two clocks (when tWR > tCK).
3. A8 and A9 = “Don’t Care.”
*CAS latency indicated in parentheses.
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
TIMING PARAMETERS
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
AH111ns
t
AS 1.5 1.5 2 ns
t
CH 2 2.5 2.75 ns
t
CL 2 2.5 2.75 ns
t
CK (3) 5 6 7 ns
t
CK (2) 10 10 ns
t
CK (1) 20 20 ns
t
CKH 1 1 1 ns
t
CKS 1.5 2 2 ns
t
CMH 1 1 1 ns
DON’T CARE
ENABLE AUTO PRECHARGE
t
CH
t
CL
t
CK
t
RP
t
RAS
t
RCD
t
RC
CKE
CLK
DQ
A10
t
CMH
t
CMS
t
AH
t
AS
ROW
ROW
BANK BANK
ROW
ROW
BANK
t
WR
DIN m
t
DH
t
DS
DIN m + 1 DIN m + 2 DIN m + 3
COMMAND
t
CMH
t
CMS
NOPNOP NOPACTIVE NOP WRITE NOP ACTIVE
t
AH
t
AS
t
AH
t
AS
t
DH
t
DS
t
DH
t
DS
t
DH
t
DS
t
CKH
t
CKS
NOP NOP
COLUMN m
3
2
T0 T1 T2 T4T3 T5 T6 T7 T8 T9
BA0, BA1
DQM 0-3
A0-A9
50
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
ALTERNATING BANK WRITE ACCESSES
1
t
CH
t
CL
t
CK
CLK
DQ
DIN m
t
DH
t
DS
DIN m + 1 DIN m + 2 DIN m + 3
COMMAND
t
CMH
t
CMS
NOP NOPACTIVE NOP WRITE NOP NOP ACTIVE
t
DH
t
DS
t
DH
t
DS
t
DH
t
DS
ACTIVE WRITE
DIN b
t
DH
t
DS
DIN b + 1 DIN b + 3
t
DH
t
DS
t
DH
t
DS
ENABLE AUTO PRECHARGE
DQM /
DQML, DQMH
A0-A9
BA0, BA1
A10
t
CMH
t
CMS
t
AH
t
AS
t
AH
t
AS
t
AH
t
AS
ROW
ROW
ROW
ROW
ENABLE AUTO PRECHARGE
ROW
ROW
BANK 0 BANK 0 BANK 1
BANK 0
BANK 1
CKE
t
CKH
t
CKS
DIN b + 2
t
DH
t
DS
COLUMN b
2
COLUMN m
2
t
RP - BANK 0
t
RAS - BANK 0
t
RCD - BANK 0
t
t
RCD - BANK 0
t
WR - BANK 0
WR - BANK 1
t
RCD - BANK 1
t
t
RC - BANK 0
RRD
T0 T1 T2 T3 T4 T5 T6 T7 T8 T9
NOTE: 1. For this example, the burst length = 4.
2. Faster frequencies require two clocks (when tWR > tCK).
3. A8 and A9 = “Don’t Care.”
*CAS latency indicated in parentheses.
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
DH111ns
t
DS 1.5 1.5 2 n s
t
RAS 38.7 42 120,000 42 120,000 ns
t
RC 55 60 70 n s
t
R CD 15 18 20 n s
t
RP 15 18 20 n s
t
R RD 10 12 14 n s
t
WR 2 tCK 1 CLK+ 1 CLK+ ns
67
TIMING PARAMETERS
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
AH111ns
t
AS 1.5 1.5 2 n s
t
CH 2 2.5 2.75 ns
t
CL 2 2.5 2.75 n s
t
CK (3) 5 6 7 ns
t
CK (2) 10 10 ns
t
CK (1) 20 20 ns
t
CKH 1 1 1 ns
t
CKS 1.5 2 2 ns
t
CMH111ns
t
CM S 1.5 1.5 2 ns
51
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
WRITE – FULL-PAGE BURST
NOTE: 1. A8 and A9 = “Don’t Care.”
2.tWR must be satisfied prior to PRECHARGE command.
3. Page left open; no tRP.
*CAS latency indicated in parentheses.
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
CKH 1 1 1 ns
t
CKS 1.5 1.5 2 ns
t
CMH111ns
t
CMS 1.5 2 2 ns
t
DH111ns
t
DS 1.5 1.5 2 n s
t
R CD 15 18 20 n s
TIMING PARAMETERS
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
AH111ns
t
AS 1.5 1.5 2 n s
t
CH 2 2.5 2.75 ns
t
CL 2 2.5 2.75 n s
t
CK (3) 5 6 7 ns
t
CK (2) 10 10 ns
t
CK (1) 20 20 ns
t
CH
t
CL
t
CK
t
RCD
CKE
CLK
A10
t
CMS
t
AH
t
AS
t
AH
t
AS
ROW
ROW
Full-page burst does not self-terminate. Can use BURST TERMINATE command to stop.
2, 3
()(
)
()(
)
()(
)
()(
)
Full page completed
DON’T CARE
COMMAND
t
CMH
t
CMS
NOPNOP NOPACTIVE NOP WRITE BURST TERMNOP NOP
()(
)
()(
)
()(
)
()(
)
DQ
DIN m
t
DH
t
DS
DIN m + 1 DIN m + 2 DIN m + 3
t
DH
t
DS
t
DH
t
DS
t
DH
t
DS
DIN m - 1
t
DH
t
DS
t
AH
t
AS
BANK
()(
)
()(
)
BANK
t
CMH
t
CKH
t
CKS
()(
)
()(
)
()(
)
()(
)
()(
)
()(
)
256 locations within same row
COLUMN m
1
T0 T1 T2 T3 T4 T5 Tn + 1 Tn + 2 Tn + 3
BA0, BA1
DQM 0-3
A0-A9
52
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
WRITE – DQM OPERATION
1
NOTE: 1. For this example, the burst length = 4.
2. A8 and A9 = “Don’t Care.”
*CAS latency indicated in parentheses.
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
CKH 1 1 1 ns
t
CKS 1.5 2 2 ns
t
CMH111ns
t
CM S 1.5 1.5 2 n s
t
DH111ns
t
DS 1.5 1.5 2 n s
t
R CD 15 18 20 n s
TIMING PARAMETERS
-5 -6 -7
SYMBOL* MIN MAX MIN MAX MIN MAX UNITS
t
AH111ns
t
AS 1.5 1.5 2 n s
t
CH 2 2.5 2.75 ns
t
CL 2 2.5 2.75 n s
t
CK (3) 5 6 7 ns
t
CK (2) 10 10 ns
t
CK (1) 20 20 ns
DON’T CARE
t
CH
t
CL
t
CK
t
RCD
CKE
CLK
DQ
A10
t
CMS
t
AH
t
AS
ROW
BANK
ROW
BANK
ENABLE AUTO PRECHARGE
DIN m + 3
t
DH
t
DS
DIN m
DIN m + 2
t
CMH
COMMAND
NOPNOP NOPACTIVE NOP WRITE NOPNOP
t
CMS
t
CMH
t
DH
t
DS
t
DH
t
DS
t
AH
t
AS
t
AH
t
AS
DISABLE AUTO PRECHARGE
t
CKH
t
CKS
COLUMN m
2
T0 T1 T2 T3 T4 T5 T6 T7
BA0, BA1
DQM 0-3
A0-A9
53
64Mb: x32 SDRAM Micron Technology, Inc., reserves the right to change products or specifications without notice. 64MSDRAMx32_5.p65 – Rev. B; Pub. 6/02 ©2002, Micron Technology, Inc.
64Mb: x32
SDRAM
86-PIN PLASTIC TSOP (400 MIL)
SEE DETAIL A
R 1.00
(2X)
R .75 (2X)
.50 TYP
.61
10.16 ±.08
.50 ±.10
11.76 ±.10
PIN #1 ID
DETAIL A
22.22 ±.08
0.20
+.07
-.03
.15
+.03
-.02
.10
+.10
-.05
1.20 MAX
.10
.25
GUAGE PLANE
.80 TYP
.10 (2X)
2.80 (2X)
NOTE: 1. All dimensions in millimeters
MAX
or typical where noted.
MIN
2. Package width and length do not include mold protrusion; allowable mold protrusion is 0.025mm per side.
8000 S. Federal Way, P.O. Box 6, Boise, ID 83707-0006, Tel: 208-368-3900
E-mail: prodmktg@micronsemi.com, Internet: http://www.micronsemi.com, Customer Comment Line: 800-932-4992
Micron and the M logo are registered trademarks and the Micron logo is a trademark of Micron Technology, Inc.
Loading...