is 1.5V + 0.1V . The Cyp ress QDR devices exceed th e QDR consorti um specifi catio n and ar e capab le of support ing V
DDQ
= 1.4V to V
DD
.
Functional Description
■ Separate independent read and write data ports
❐ Supports concurrent transactions
■ 300 MHz to 400 MHz clock for high bandwidth
■ 4-word burst to reduce address bus frequency
■ Double Data Rate (DDR) interfaces on both read and write ports
(data transferred at 800 MHz) at 400 MHz
■ Read latency of 2.5 clock cycles
■ Two input clocks (K and K) for precise DDR timing
❐ SRAM uses rising edges only
■ Echo clocks (CQ and CQ) simplify data capture in high speed
systems
■ Single multiplexed address input bus latches address inputs
for both read and write ports
■ Separate port selects for depth expansion
■ Data valid pin (QVLD) to indicate valid data on the output
■ Synchronous internally self-timed writes
■ Available in x8, x9, x18, and x36 configurations
■ Full data coherency providing most current data
■ Core V
■ Available in 165-ball FBGA package (13 x 15 x 1.4 mm)
■ Offered in both Pb-free and non Pb-free packages
■ Variable drive HSTL output buffers
■ JTAG 1149.1 compatible test access port
■ Delay Lock Loop (DLL) for accurate data placement
= 1.8V ± 0.1V; IO V
DD
= 1.4V to V
DDQ
DD
[1]
The CY7C1161V18, CY7C1176V18, CY7C1163V18, and
CY7C1165V18 are 1.8V Synchronous Pipelined SRAMs
equipped with QDR™-II+ architecture. QDR-II+ architecture
consists of two separate ports to access the memory array. The
read port has dedicated data outputs to support read operations
and the write port has dedicated data inputs to support write
operations. QDR-II+ architecture has separate data inputs and
data outputs to completely eliminate the need to turn around the
data bus that is required with common IO devices. Each port can
be accessed through a common address bus. Addresses for
read and write addresses are latched onto alternate rising edges
of the input (K) clock. Accesses to the QDR-II+ read and write
ports are completely independent of one another. In order to
maximize data throughput, both read and write ports are
equipped with Double Data Rate (DDR) interfaces. Each
address location is associated with four 8-bit words
(CY7C1161V18), 9-bit words (CY7C1176V18), 18-bit words
(CY7C1163V18), or 36-bit words (CY7C1165V18) that burst
sequentially into or out of the device. Because data can be transferred into and out of the device on every rising edge of both input
clocks K and K
, memory bandwidth is maximized while simpli-
fying system design by eliminating bus turnarounds.
Depth expansion is accomplished with port selects for each port.
Port selects allow each port to operate independently.
All synchronous inputs pass through input registers controlled by
the K or K
registers controlled by the or K or K
input clocks. All data outputs pass through output
input clocks. Writes are
conducted with on-chip synchronous self-timed write circuitry.
Configurations
With cycle read latency of 2.5 cycles:
CY7C1161V18 – 2M x 8
CY7C1176V18 – 2M x 9
CY7C1163V18 – 1M x 18
CY7C1165V18 – 512K x 36
Selection Guide
Description400 MHz375 MHz333 MHz300 MHzUnit
Maximum Operating Frequency 400375333300MHz
Maximum Operating Current 10801020920850mA
Cypress Semiconductor Corporation•198 Champion Court•San Jose, CA 95134-1709•408-943-2600
Document Number: 001-06582 Rev. *D Revised March 06, 2008
[+] Feedback [+] Feedback
CY7C1161V18, CY7C1176V18
CY7C1163V18, CY7C1165V18
Logic Block Diagram (CY7C1161V18)
512K x 8 Array
CLK
A
(18:0)
Gen.
K
K
Control
Logic
Address
Register
D
[7:0]
Read Add. Decode
Read Data Reg.
RPS
WPS
Q
[7:0]
Control
Logic
Address
Register
Reg.
Reg.
Reg.
16
19
8
32
8
NWS
[1:0]
V
REF
Write Add. Decode
Write
Reg
16
A
(18:0)
19
512K x 8 Array
512K x 8 Array
512K x 8 Array
Write
Reg
Write
Reg
Write
Reg
8
CQ
CQ
DOFF
QVLD
512K x 9 Array
CLK
A
(18:0)
Gen.
K
K
Control
Logic
Address
Register
D
[8:0]
Read Add. Decode
Read Data Reg.
RPS
WPS
Q
[8:0]
Control
Logic
Address
Register
Reg.
Reg.
Reg.
18
19
9
36
9
BWS
[0]
V
REF
Write Add. Decode
Write
Reg
18
A
(18:0)
19
512K x 9 Array
512K x 9 Array
512K x 9 Array
Write
Reg
Write
Reg
Write
Reg
9
CQ
CQ
DOFF
QVLD
Logic Block Diagram (CY7C1176V18)
Document Number: 001-06582 Rev. *DPage 2 of 29
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CY7C1161V18, CY7C1176V18
CY7C1163V18, CY7C1165V18
Logic Block Diagram (CY7C1163V18)
256K x 18 Array
CLK
A
(17:0)
Gen.
K
K
Control
Logic
Address
Register
D
[17:0]
Read Add. Decode
Read Data Reg.
RPS
WPS
Q
[17:0]
Control
Logic
Address
Register
Reg.
Reg.
Reg.
36
18
18
72
18
BWS
[1:0]
V
REF
Write Add. Decode
Write
Reg
36
A
(17:0)
18
256K x 18 Array
256K x 18 Array
256K x 18 Array
Write
Reg
Write
Reg
Write
Reg
18
CQ
CQ
DOFF
QVLD
128K x 36 Array
CLK
A
(16:0)
Gen.
K
K
Control
Logic
Address
Register
D
[35:0]
Read Add. Decode
Read Data Reg.
RPS
WPS
Q
[35:0]
Control
Logic
Address
Register
Reg.
Reg.
Reg.
72
17
36
144
36
BWS
[3:0]
V
REF
Write Add. Decode
Write
Reg
72
A
(16:0)
17
128K x 36 Array
128K x 36 Array
128K x 36 Array
Write
Reg
Write
Reg
Write
Reg
36
CQ
CQ
DOFF
QVLD
Logic Block Diagram (CY7C1165V18)
Document Number: 001-06582 Rev. *DPage 3 of 29
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CY7C1161V18, CY7C1176V18
CY7C1163V18, CY7C1165V18
Pin Configurations
CY7C1161V18 (2M x 8)
165-Ball FBGA (13 x 15 x 1.4 mm) Pinout
23
4
5
6
7
1
A
B
C
D
E
F
G
H
J
K
L
M
N
P
R
A
CQ
NC
NC
NC
NC
DOFF
NC
NC/72MA
NWS
1
K
WPS
NC/144M
NCNC
NC
NC
NC
TDO
NC
NC
D5
NC
NC
NC
TCK
NC
NC
A NC/288MKNWS
0
V
SS
ANCA
NCV
SS
V
SS
V
SS
V
SS
V
DD
A
V
SS
V
SS
V
SS
V
DD
Q4
NC
V
DDQ
NC
NC
NC
NC
Q7
A
V
DDQ
V
SS
V
DDQ
V
DD
V
DD
Q5V
DDQ
V
DD
V
DDQ
V
DD
V
DDQ
V
DD
V
SS
V
DD
V
DDQ
V
DDQ
V
SS
V
SS
V
SS
V
SS
A
ANC
V
SS
A
A
A
D4V
SS
NCV
SS
NC
NC
V
REF
V
SS
V
DD
V
SS
V
SS
A
V
SS
QVLD
NC
Q6
NC
D7
D6
V
DD
A
8
91011
NC
ANC/36M
RPS
CQ
A NCNCQ3
V
SS
NCNCD3
NC
V
SS
NC
Q2
NC
NC
NC
V
REF
NC
NC
V
DDQ
NC
V
DDQ
NCNC
V
DDQ
V
DDQ
V
DDQ
D1V
DDQ
NC
Q1
NC
V
DDQ
V
DDQ
NC
V
SS
NCD0
NC
TDITMS
V
SS
A
NC
A
NC
D2
NC
ZQ
NC
Q0
NC
NC
NC
NC
A
NC/144M
CY7C1176V18 (2M x 9)
23
4
5
6
7
1
A
B
C
D
E
F
G
H
J
K
L
M
N
P
R
A
CQ
NC
NC
NC
NC
DOFF
NC
NC/72MANC K
WPSNC/144M
NCNC
NC
NC
NC
TDO
NC
NC
D6
NC
NC
NC
TCK
NC
NC
A NC/288MKBWS
0
V
SS
ANCA
NCV
SS
V
SS
V
SS
V
SS
V
DD
A
V
SS
V
SS
V
SS
V
DD
Q5
NC
V
DDQ
NC
NC
NC
NC
Q8
A
V
DDQ
V
SS
V
DDQ
V
DD
V
DD
Q6V
DDQ
V
DD
V
DDQ
V
DD
V
DDQ
V
DD
V
SS
V
DD
V
DDQ
V
DDQ
V
SS
V
SS
V
SS
V
SS
A
ANC
V
SS
A
A
A
D5V
SS
NCV
SS
NC
NC
V
REF
V
SS
V
DD
V
SS
V
SS
A
V
SS
QVLD
NC
Q7
NC
D8
D7
V
DD
A
8
91011
Q0
ANC/36MRPS
CQ
A
NC
NCQ4
V
SS
NCNCD4
NC
V
SS
NC
Q3
NC
NC
NC
V
REF
NC
NC
V
DDQ
NC
V
DDQ
NCNC
V
DDQ
V
DDQ
V
DDQ
D2V
DDQ
NC
Q2
NC
V
DDQ
V
DDQ
NC
V
SS
NCD1
NC
TDITMS
V
SS
A
NC
A
NC
D3
NC
ZQ
NC
Q1
NC
NC
D0
NC
A
NC
NC
Document Number: 001-06582 Rev. *DPage 4 of 29
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CY7C1161V18, CY7C1176V18
CY7C1163V18, CY7C1165V18
Pin Configurations (continued)
CY7C1163V18 (1M x 18)
165-Ball FBGA (13 x 15 x 1.4 mm) Pinout
23
4
567
1
A
B
C
D
E
F
G
H
J
K
L
M
N
P
R
A
CQ
NC
NC
NC
NC
DOFF
NC
NC/144M NC/36MBWS
1
KWPSNC/288M
Q9D9
NC
NC
NC
TDO
NC
NC
D13
NC
NC
NC
TCK
NC
D10
A NC KBWS
0
V
SS
ANCA
Q10V
SS
V
SS
V
SS
V
SS
V
DD
A
V
SS
V
SS
V
SS
V
DD
Q11
D12
V
DDQ
D14
Q14
D16
Q16
Q17
A
V
DDQ
V
SS
V
DDQ
V
DD
V
DD
Q13V
DDQ
V
DD
V
DDQ
V
DD
V
DDQ
V
DD
V
SS
V
DD
V
DDQ
V
DDQ
V
SS
V
SS
V
SS
V
SS
A
A
V
SS
A
A
A
D11V
SS
NCV
SS
Q12
NC
V
REF
V
SS
V
DD
V
SS
V
SS
A
V
SS
QVLD
NC
Q15
NC
D17
D15
V
DD
A
8
91011
Q0
ANC/72MRPS
CQ
A NCNCQ8
V
SS
NCQ7D8
NC
V
SS
NC
Q6
D5
NC
NC
V
REF
NC
Q3
V
DDQ
NC
V
DDQ
NCQ5
V
DDQ
V
DDQ
V
DDQ
D4V
DDQ
NC
Q4
NC
V
DDQ
V
DDQ
NC
V
SS
NCD2
NC
TDITMS
V
SS
A
NC
A
D7
D6
NC
ZQ
D3
Q2
D1
Q1
D0
NC
A
NC
CY7C1165V18 (512K x 36)
23
456
7
1
A
B
C
D
E
F
G
H
J
K
L
M
N
P
R
A
CQ
Q27
D27
D28
D34
DOFF
Q33
NC/288M NC/72M
BWS
2
KWPSBWS
1
Q18
D18
Q30
D31
D33
TDO
Q28
D29
D22
D32
Q34
Q31
TCK
D35
D19
A
BWS
3
K
BWS
0
V
SS
ANCA
Q19V
SS
V
SS
V
SS
V
SS
V
DD
A
V
SS
V
SS
V
SS
V
DD
Q20
D21
V
DDQ
D23
Q23
D25
Q25
Q26
A
V
DDQ
V
SS
V
DDQ
V
DD
V
DD
Q22V
DDQ
V
DD
V
DDQ
V
DD
V
DDQ
V
DD
V
SS
V
DD
V
DDQ
V
DDQ
V
SS
V
SS
V
SS
V
SS
A
A
NC
V
SS
A
A
A
D20V
SS
Q29V
SS
Q21
D30
V
REF
V
SS
V
DD
V
SS
V
SS
A
V
SS
QVLD
Q32
Q24
Q35
D26
D24
V
DD
A
891011
Q0
NC/36M
NC/144M
RPS
CQ
A D17
Q17
Q8
V
SS
D16Q7D8
Q16
V
SS
D15
Q6
D5
D9
Q14
V
REF
Q11
Q3
V
DDQ
Q15
V
DDQ
D14Q5
V
DDQ
V
DDQ
V
DDQ
D4V
DDQ
D12
Q4
Q12
V
DDQ
V
DDQ
D11
V
SS
D10D2
Q10
TDITMS
V
SS
A
Q9
A
D7
D6
D13
ZQ
D3
Q2
D1
Q1
D0
Q13
A
Document Number: 001-06582 Rev. *DPage 5 of 29
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CY7C1161V18, CY7C1176V18
CY7C1163V18, CY7C1165V18
Pin Definitions
Pin NameIOPin Description
D
[x:0]
Input-
Synchronous
WPSInput-
Synchronous
, BWS1,
,Input-
1
Synchronous
Input-
Synchronous
3
NWS0, NWS
BWS
0
BWS2, BWS
AInput-
Synchronous
Data Input Signals. Sampled on the rising edge of K and K clocks during valid write operations.
CY7C1 161V18−D
CY7C1 176V18−D
CY7C1 163V18−D
CY7C1 165V18−D
[7:0]
[8:0]
[17:0]
[35:0]
Write Port Select − Active LOW . Sampled on the rising edge of the K clock. When asserted active,
a write operation is initiated. Deasserting deselects the write port. Deselecting the write port causes
D
to be ignored.
[x:0]
Nibble Write Select 0, 1 − Active LOW (CY7C1161V18Only). Sampled on the rising edge of the
K and K
controls D
All the nibble write selects are sampled on the same edge as the data. Deselecting a nibble write
clocks during Write operations. Used to select the nibble that is written into the device. NWS0
and NWS1 controls D
[3:0]
[7:4]
.
select causes the corresponding nibble of data to be ignored and not written into the device.
Byte Write Select 0, 1, 2, and 3 − Active LOW. Sampled on the rising edge of the K and K clocks
during write operations. Used to select the byte that is written into the device during the current portion
of the write operation. Bytes not written remain unaltered.
CY7C1 176V18 − BWS
CY7C1 163V18 − BWS0 controls D
CY7C1 165V18 − BWS0 controls D
controls D
All the Byte Write Selects are sampled on the same edge as the data. Deselecting a Byte Write Select
[35:27].
controls D
0
[8:0].
and BWS1 controls D
[8:0]
, BWS1 controls D
[8:0]
causes the corresponding byte of data to be ignored and not written into the device.
Address Inputs. Sampled on the rising edge of the K clock during active read and write operations.
These address inputs are multiplexed for both read and write operations. Internally, the device is
organized as 2M x 8 (4 arrays each of 512K x 8) for CY7C1161V18, 2M x 9 (4 arrays each of 512K
x 9) for CY7C1176V18, 1M x 18 (4 arrays each of 256K x 18) for CY7C1163V18, and 512K x 36 (4
arrays each of 128K x 36) for CY7C1165V18. Therefore, only 19 address inputs are needed to access
the entire memory array of CY7C1161V18 and CY7C1 176V18, 18 address inputs for CY7C1 163V18,
and 17 address inputs for CY7C1165V18. These inputs are ignored when the appropriate port is
deselected.
[17:9]..
, BWS2 controls D
[17:9]
[26:18],
and BWS3
Q
[x:0]
RPSInput-
Outputs-
Synchronous
Synchronous
Data Output Signals. These pins drive out the requested data during a read operation. Valid data
is driven out on the rising edge of both the K and K
in single clock mode. When the read port is deselected, Q
CY7C1 161V18 − Q
CY7C1 176V18 − Q
CY7C1 163V18 − Q
CY7C1 165V18 − Q
[7:0]
[8:0]
[17:0]
[35:0]
.
.
.
.
clocks during read operations or K and K when
are automatically tri-stated.
[x:0]
Read Port Select − Active LOW . Sampled on the rising edge of positive input clock (K). When active,
a read operation is initiated. Deasserting causes the read port to be deselected. When deselected,
the pending access is enabled to complete and the output drivers are automatically tri-stated following
the next rising edge of the K clock. Each read access consists of a burst of four sequential transfers.
QVLDValid Output
Valid Output Indicator. Indicates valid output data. QVLD is edge-aligned with CQ and CQ.
Indicator
KInput-
Clock
K
InputClock
Positive Input Clock Input. Rising edge of K is used to capture synchronous inputs to the device
and to drive out data through Q
edge of K.
when in single clock mode. All accesses are initiated on the rising
[x:0]
Negative Input Clock Input. K is used to capture synchronous inputs presented to the device and
to drive out data through Q
when in single clock mode.
[x:0]
CQEcho ClockSynchronous Echo Clock Outputs. This is a free running clock and is synchronized to the input
clock (K) of the QDR-II+. The timings for the echo clocks are shown in “Switching Characteristics”
on page 23.
Document Number: 001-06582 Rev. *DPage 6 of 29
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CY7C1161V18, CY7C1176V18
CY7C1163V18, CY7C1165V18
Pin Definitions (continued)
Pin NameIOPin Description
CQ
ZQInputOutput Impedance Matching Input. Used to tune the device outputs to the system data bus
DOFF
TDOOutputTDO for JTAG.
TCKInputTCK Pin for JTAG.
TDIInputTDI Pin for JTAG.
TMSInputTMS Pin for JTAG.
NCN/ANot Connected to the Die. Can be tied to any voltage level.
NC/36MN/ANot Connected to the Die. Can be tied to any voltage level.
NC/72MN/ANot Connected to the Die. Can be tied to any voltage level.
NC/144MN/ANot Connected to the Die. Can be tied to any voltage level.
Echo ClockSynchronous Echo Clock Outputs. This is a free running clock and is synchronized to the input
clock (K
on page 23.
impedance. CQ, CQ
connected between ZQ and ground. Alternatively, this pin is connected directly to V
enables the minimum impedance mode. This pin cannot be connected directly to GND or left unconnected.
InputDLL Turn Off − Active LOW. Connecting this pin to ground turns off the DLL inside the device. The
timings in the DLL turned-off operation are different from those listed in this data sheet. For normal
operation, this pin is connected to a pull up through a 10 KΩ or less pull up resistor. The device
behaves in QDR-I mode when the DLL is turned off. In this mode, the device operates at a frequency
of up to 167 MHz with QDR-I timing.
) of the QDR-II+. The timings for the echo clocks are shown in “Switching Characteristics”
and Q
output impedance are set to 0.2 x RQ, where RQ is a resistor
[x:0]
DDQ
, which
NC/288MN/ANot Connected to the Die. Can be tied to any voltage level.
V
V
V
V
REF
DD
SS
DDQ
Input-
Reference
Power Supply Power Supply Inputs to the Core of the Device.
GroundGround for the Device.
Power Supply Power Supply Inputs for the Outputs of the Device.
Reference Volt age Input. Static input used to set the reference level for HSTL inputs, outputs, and
AC measurement points.
Document Number: 001-06582 Rev. *DPage 7 of 29
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CY7C1161V18, CY7C1176V18
CY7C1163V18, CY7C1165V18
Functional Overview
The CY7C1161V18, CY7C1176V18, CY7C1163V18, and
CY7C1165V18 are synchronous pipelined burst SRAMs
equipped with both a read port and a write port. The read port is
dedicated to read operations and the write port is dedicated to
write operations. Data flows into the SRAM through the write port
and out through the read port. These devices multiplex the
address inputs in order to minimize the number of address pins
required. By having separate read and write ports, the QDR-II+
completely eliminates the need to “turn-around” the data bus. It
avoids any possible data contention, thereby , simplify ing system
design. Each access consists of four 8-bit data transfers in the
case of CY7C1161V18, four 9-bit data transfers in the case of
CY7C1176V18, four 18-bit data transfers in the case of
CY7C1163V18, and four 36-bit data transfers in the case of
CY7C1165V18 in two clock cycles.
Accesses for both ports are initiated on the positive input clock
(K). All synchronous input and output timings are referenced to
the rising edge of the Input clocks (K/K
All synchronous data inputs (D
controlled by the input clocks (K and K
outputs (Q
rising edge of the Input clocks (K and K
) pass through output registers controlled by the
[x:0]
[x:0]
All synchronous control (RPS, WPS, BWS
through input registers controlled by the rising edge of the input
clocks (K and K).
CY7C1163V18 is described in the following sections. The same
basic descriptions apply to CY7C1161V18, CY7C1176V18, and
CY7C1165V18.
Read Operations
The CY7C1163V18 is organized internally as four arrays of 256K
x 18. Accesses are completed in a burst of four sequential 18-bit
data words. Read operations are initiated by asserting RPS
active at the rising edge of the positive input clock (K). The
address presented to address inputs are stored in the Read
address register. Following the next two K clock rises, the corresponding lowest order 18-bit word of data is driven onto the
using K as the output timing reference. On the subse-
Q
[17:0]
quent rising edge of K, the next 18-bit data word is driven onto
the Q
have been driven out onto Q
0.45 ns from the rising edge of the Input clock K or K
maintain the internal logic, each read access must be allowed to
complete. Each read access consists of four 18-bit data words
and takes two clock cycles to complete. Therefore, read
accesses to the device cannot be initiated on two consecutive K
clock rises. The internal logic of the device ignores the second
read request. Read accesses can be initiated on every other K
clock rise. Doing so pipelines the data flow such that data is
transferred out of the device on every rising edge of the input
clocks K and K
When the read port is deselected, the CY7C1163V18 first
completes the pending read transactions. Synchronous internal
circuitry automatically tri-states the outputs following the next
rising edge of the negative input clock (K
seamless transition between devices without the insertion of wait
states in a depth expanded memory.
. This process continues until all four 18-bit data words
[17:0]
[17:0]
.
).
) pass through input registers
). All synchronous data
) also.
) inputs pass
[x:0]
. The requested data is valid
. In order to
). This allows for a
Write Operations
Write operations are initiated by asserting WPS active at the
rising edge of the positive input clock (K). On the following K
clock rise, the data presented to D
the lower 18-bit write data register, provided BWS
asserted active. On the subsequent rising edge of the negative
input clock (K), the information presented to D
into the write data register, provided BWS
active. This process continues for one more cycle until four 18-bit
is latched and stored into
[17:0]
[1:0]
[1:0]
is also stored
[17:0]
are both asserted
are both
words (a total of 72 bits) of data are stored in the SRAM. The 72
bits of data are then written into the memory array at the specified
location. Therefore, write accesses to the device cannot be
initiated on two consecutive K clock rises. The inte rnal logic of
the device ignores the second write request. Write accesses are
initiated on every other rising edge of the positive input clock (K).
Doing so pipelines the data flow such that 18 bits of data can be
transferred into the device on every rising edge of the input
clocks (K and K
).
When deselected, the write port ignores all inputs after the
pending write operations are completed.
Byte Write Operations
Byte write operations are supported by the CY7C1163V18. A
write operation is initiated as described in the Write Operations
section above. The bytes that are written are determined by
BWS
and BWS1, which are sampled with each set of 18-bit data
0
words. Asserting the appropriate byte write select input during
the data portion of a write enables the data being presented to
be latched and written into the device. Deasserting the byte write
select input during the data portion of a write allows the data
stored in the device for that byte to remain unaltered. This feature
is used to simplify read, modify, and write operations to a byte
write operation.
Concurrent Transactions
The read and write ports on the CY7C1163V18 operate
completely independent of one another. Because each port
latches the address inputs on different clock edges, the user can
read or write to any location, regardless of the transaction on the
other port. If the ports access the same location when a read
follows a write in successive clock cycles, the SRAM delivers the
most recent information associated with the specified address
location. This includes forwarding data from a write cycle initiated
on the previous K clock rise.
Read accesses and write access are scheduled such that one
transaction is initiated on any clock cycle. If both ports are
selected on the same K clock rise, the arbitration depends on the
previous state of the SRAM. If both ports are deselected, the
read port takes priority . If a read is initiated on the previous cycle,
the write port assumes priority (because read operations cannot
be initiated on consecutive cycles). If a write was initiated on the
previous cycle, the read port assumes priority (because write
operations cannot be initiated on consecutive cycles). Therefore,
asserting both port selects active from a deselected state results
in alternating read or write operations initiated, with the first
access being a read.
Document Number: 001-06582 Rev. *DPage 8 of 29
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CY7C1161V18, CY7C1176V18
CY7C1163V18, CY7C1165V18
Depth Expansion
The CY7C1163V18 has a port select input for each port. This
enables easy depth expansion. Both port selects are only
sampled on the rising edge of the positive input clock (K). Each
port select input can deselect the specified port. Deselecting a
port does not affect the other port. All pending transactions (read
and write) are completed before the device is deselected.
Programmable Impedance
An external resistor, RQ, must be connected between the ZQ pin
on the SRAM and V
driver impedance. The value of RQ must be 5X the value of the
intended line impedance driven by the SRAM. The allowable
range of RQ to guarantee impedance matching with a tolerance
of ±15% is between 175Ω and 350Ω
output impedance is adjusted every 1024 cycles upon power up
to account for drifts in supply voltage and temperature.
to enable the SRAM to adjust its output
SS
, with V
=1.5V. The
DDQ
Echo Clocks
Echo clocks are provided on the QDR-II+ to simplify data capture
on high speed systems. Two echo clocks are generated by the
QDR-II+. CQ is referenced with respect to K and CQ is referenced with respect to K
synchronized to the inputclock of the QDR-II+. The timings for
the echo clocks are shown in the AC timing table.
. These are free running clocks and are
Valid Data Indicator (QVLD)
QVLD is provided on the QDR-II+ to simplify data capture on high
speed systems. The QVLD is generated by the QDR-II+ device
along with data output. This signal is also edge-aligned with the
echo clock and follows the timing of any data pin. This signal is
asserted half a cycle before valid data arrives.
DLL
These chips utilize a Delay Lock Loop (DLL) that is designed to
function between 120 MHz and the specified maximum clock
frequency. The DLL may be disabled by applying ground to the
DOFF
pin. When the DLL is turned off, the device behaves in
QDR-I mode (with 1.0 cycle latency and a longer access time).
For more information, refer to the application note, “DLL Consid-
erations in QDRII/DDRII/QDRII+/DDRII+.” The DLL can also be
reset by slowing or stopping the input clocks K and K
minimum of 30 ns. However, it is not necessary for the DLL to be
reset in order to lock to the desired frequency. During power up
when the DOFF
of stable clock.
is tied HIGH, the DLL is locked after 2048 cycles
for a
Document Number: 001-06582 Rev. *DPage 9 of 29
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