Cypress CY7C1510KV18, CY7C1512KV18, CY7C1525KV18, CY7C1514KV18 User Manual

72-Mbit QDR™-II SRAM 2-Word
Burst Architecture
CY7C1510KV18, CY7C1525KV18 CY7C1512KV18, CY7C1514KV18

Features

Configurations

Separate Independent Read and Write Data PortsSupports concurrent transactions
333 MHz Clock for High Bandwidth
2-word Burst on all Accesses
Double Data Rate (DDR) Interfaces on both Read and Write
Ports (data transferred at 666 MHz) at 333 MHz
Two Input Clocks (K and K) for precise DDR timingSRAM uses rising edges only
Two Input Clocks for Output Data (C and C) to minimize Clock
Skew and Flight Time mismatches
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
Synchronous internally Self-timed Writes
QDR™-II operates with 1.5 Cycle Read Latency when DOFF
is asserted HIGH
Operates similar to QDR-I Device with 1 Cycle Read Latency
when DOFF
Available in x8, x9, x18, and x36 Configurations
Full Data Coherency, providing Most Current Data
Core VSupports both 1.5V and 1.8V IO supply
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
Phase Locked Loop (PLL) for Accurate Data Placement
is asserted LOW
= 1.8V (±0.1V); IO V
DD
= 1.4V to V
DDQ
DD
CY7C1510KV18 – 8M x 8
CY7C1525KV18 – 8M x 9
CY7C1512KV18 – 4M x 18
CY7C1514KV18 – 2M x 36

Functional Description

The CY7C1510KV18, CY7C1525KV18, CY7C1512KV18, and CY7C1514KV18 are 1.8V Synchronous Pipelined SRAMs, equipped with QDR-II architecture. QDR-II architecture consists of two separate ports: the read port and the write port 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 “turnaround” the data bus that exists with common I/O devices. Access to each port is through a common address bus. Addresses for read and write addresses are latched on alternate rising edges of the input (K) clock. Accesses to the QDR-II read and write ports are completely independent of one another. To maximize data throughput, both read and write ports are equipped with DDR interfaces. Each address location is associated with two 8-bit words (CY7C1510KV18), 9-bit words (CY7C1525KV18), 18-bit words (CY7C1512KV18), or 36-bit words (CY7C1514KV18) 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 and C
), memory bandwidth is maximized while simplifying
system design by eliminating bus turnarounds.
Depth expansion is accomplished with port selects, which enables each port to operate independently.
All synchronous inputs pass through input registers controlled by the K or K
input clocks. All data outputs pass through output registers controlled by the C or C (or K or K in a single clock domain) input clocks. Writes are conducted with on-chip synchronous self-timed write circuitry.
and C
Table 1. Selection Guide
Description 333 MHz 300 MHz 250 MHz 200 MHz 167 MHz Unit
Maximum Operating Frequency 333 300 250 200 167 MHz
Maximum Operating Current x8 790 730 640 540 480 mA
x9 790 730 640 540 480
x18 810 750 650 550 490
x36 990 910 790 660 580
Cypress Semiconductor Corporation 198 Champion Court San Jose, CA 95134-1709 408-943-2600 Document Number: 001-00436 Rev. *E Revised March 30, 2009
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CY7C1510KV18, CY7C1525KV18 CY7C1512KV18, CY7C1514KV18

Logic Block Diagram (CY7C1510KV18)

4M x 8 Array
CLK
A
(21:0)
Gen.
K
K
Control
Logic
Address Register
D
[7:0]
Read Add. Decode
Read Data Reg.
RPS
WPS
Control
Logic
Address Register
Reg.
Reg.
Reg.
8
22
16
8
NWS
[1:0]
V
REF
Write Add. Decode
Write
Reg
8
A
(21:0)
22
CQ
CQ
DOFF
Q
[7:0]
8
8
Write
Reg
C
C
4M x 8 Array
8
4M x 9 Array
CLK
A
(21:0)
Gen.
K
K
Control
Logic
Address Register
D
[8:0]
Read Add. Decode
Read Data Reg.
RPS
WPS
Control
Logic
Address Register
Reg.
Reg.
Reg.
9
22
18
9
BWS
[0]
V
REF
Write Add. Decode
Write
Reg
9
A
(21:0)
22
CQ
CQ
DOFF
Q
[8:0]
9
9
Write
Reg
C
C
4M x 9 Array
9

Logic Block Diagram (CY7C1525KV18)

Document Number: 001-00436 Rev. *E Page 2 of 30
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CY7C1510KV18, CY7C1525KV18 CY7C1512KV18, CY7C1514KV18

Logic Block Diagram (CY7C1512KV18)

2M x 18 Array
CLK
A
(20:0)
Gen.
K
K
Control
Logic
Address Register
D
[17:0]
Read Add. Decode
Read Data Reg.
RPS
WPS
Control
Logic
Address Register
Reg.
Reg.
Reg.
18
21
36
18
BWS
[1:0]
V
REF
Write Add. Decode
Write
Reg
18
A
(20:0)
21
CQ
CQ
DOFF
Q
[17:0]
18
18
Write
Reg
C
C
2M x 18 Array
18
1M x 36 Array
CLK
A
(19:0)
Gen.
K
K
Control
Logic
Address Register
D
[35:0]
Read Add. Decode
Read Data Reg.
RPS
WPS
Control
Logic
Address Register
Reg.
Reg.
Reg.
36
20
72
36
BWS
[3:0]
V
REF
Write Add. Decode
Write
Reg
36
A
(19:0)
20
CQ
CQ
DOFF
Q
[35:0]
36
36
Write
Reg
C
C
1M x 36 Array
36

Logic Block Diagram (CY7C1514KV18)

Document Number: 001-00436 Rev. *E Page 3 of 30
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CY7C1510KV18, CY7C1525KV18 CY7C1512KV18, CY7C1514KV18

Pin Configuration

Note
1. NC/144M and NC/288M are not connected to the die and can be tied to any voltage level.
The pin configurations for CY7C1510KV18, CY7C1525KV18, CY7C1512KV18, and CY7C1514KV18 follow.

165-Ball FBGA (13 x 15 x 1.4 mm) Pinout

CY7C1510KV18 (8M x 8)
1 2 3 4 5 6 7 8 9 10 11
A CQ AAWPSNWS
1
B NC NC NC A NC/288M K NWS
C NC NC NC V
D NC D4 NC V
E NC NC Q4 V
F NC NC NC V
G NC D5 Q5 V
H DOFF V
REF
V
DDQ
V
J NC NC NC V
K NC NC NC V
L NC Q6 D6 V
M NC NC NC V
N NC D7 NC V
SS
SS
DDQ
DDQ
DDQ
DDQ
DDQ
DDQ
DDQ
SS
SS
AAAVSSNC NC D3
V
SS
V
SS
V
DD
V
DD
V
DD
V
DD
V
DD
V
SS
V
SS
AAAVSSNC NC NC
P NC NC Q7 A A C A A NC NC NC
R TDO TCK A A A C AAATMSTDI
K NC/144M RPS AACQ
0
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
DD
V
DD
V
DD
V
DD
V
DD
V
SS
V
SS
ANCNCQ3
V
SS
V
DDQ
V
DDQ
V
DDQ
V
DDQ
V
DDQ
V
DDQ
V
DDQ
V
SS
[1]
NC NC NC
NC D2 Q2
NC NC NC
NC NC NC
V
DDQ
V
REF
NC Q1 D1
NC NC NC
NC NC Q0
NC NC D0
ZQ
CY7C1525KV18 (8M x 9)
1 2 3 4 5 6 7 8 9 10 11
A CQ AAWPSNC K NC/144M RPS AACQ
B NC NC NC A NC/288M K BWS
C NC NC NC V
D NC D5 NC V
E NC NC Q5 V
F NC NC NC V
G NC D6 Q6 V
H DOFF V
REF
V
DDQ
V
J NC NC NC V
K NC NC NC V
L NC Q7 D7 V
M NC NC NC V
N NC D8 NC V
SS
SS
DDQ
DDQ
DDQ
DDQ
DDQ
DDQ
DDQ
SS
SS
AAAVSSNC NC D4
V
SS
V
SS
V
DD
V
DD
V
DD
V
DD
V
DD
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
DD
V
DD
V
DD
V
DD
V
DD
V
SS
V
SS
AAAVSSNC NC NC
0
ANCNCQ4
V
V
V
V
V
V
V
V
DDQ
DDQ
DDQ
DDQ
DDQ
DDQ
DDQ
V
SS
SS
NC NC NC
NC D3 Q3
NC NC NC
NC NC NC
V
DDQ
V
REF
NC Q2 D2
NC NC NC
NC NC Q1
NC NC D1
ZQ
P NC NC Q8 A A C A A NC D0 Q0
R TDO TCK A A A C AAATMSTDI
Document Number: 001-00436 Rev. *E Page 4 of 30
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CY7C1510KV18, CY7C1525KV18 CY7C1512KV18, CY7C1514KV18
Pin Configuration (continued)
The pin configurations for CY7C1510KV18, CY7C1525KV18, CY7C1512KV18, and CY7C1514KV18 follow.
165-Ball FBGA (13 x 15 x 1.4 mm) Pinout
CY7C1512KV18 (4M x 18)
1 2 3 4 5 6 7 8 9 10 11
A CQ NC/144M A WPS BWS
1
B NC Q9 D9 A NC K BWS
C NC NC D10 V
D NC D11 Q10 V
E NC NC Q11 V
F NC Q12 D12 V
G NC D13 Q13 V
H DOFF V
REF
V
DDQ
V
J NC NC D14 V
K NC NC Q14 V
L NC Q15 D15 V
M NC NC D16 V
N NC D17 Q16 V
SS
SS
DDQ
DDQ
DDQ
DDQ
DDQ
DDQ
DDQ
SS
SS
AAAVSSNC Q7 D8
V
SS
V
SS
V
DD
V
DD
V
DD
V
DD
V
DD
V
SS
V
SS
AAAVSSNC NC D1
P NC NC Q17 A A C A A NC D0 Q0
R TDO TCK A A A C AAATMSTDI
K NC/288M RPS AACQ
0
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
DD
V
DD
V
DD
V
DD
V
DD
V
SS
V
SS
ANCNCQ8
V
SS
V
DDQ
V
DDQ
V
DDQ
V
DDQ
V
DDQ
V
DDQ
V
DDQ
V
SS
[1]
NC NC D7
NC D6 Q6
NC NC Q5
NC NC D5
V
DDQ
V
REF
NC Q4 D4
NC D3 Q3
NC NC Q2
NC Q1 D2
ZQ
CY7C1514KV18 (2M x 36)
1 2 3 4 5 6 7 8 9 10 11
A CQ NC/288M A WPS BWS
B Q27 Q18 D18 A BWS
C D27 Q28 D19 V
D D28 D20 Q19 V
E Q29 D29 Q20 V
F Q30 Q21 D21 V
G D30 D22 Q22 V
H DOFF V
REF
V
DDQ
V
J D31 Q31 D23 V
K Q32 D32 Q23 V
L Q33 Q24 D24 V
M D33 Q34 D25 V
N D34 D26 Q25 V
SS
SS
DDQ
DDQ
DDQ
DDQ
DDQ
DDQ
DDQ
SS
SS
AAAVSSD16 Q7 D8
V
SS
V
SS
V
DD
V
DD
V
DD
V
DD
V
DD
V
SS
V
SS
AAAVSSQ10 D9 D1
2
3
K BWS
RPS A NC/144M CQ
1
KBWS0AD17Q17Q8
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
SS
V
DD
V
DD
V
DD
V
DD
V
DD
V
SS
V
SS
V
V
V
V
V
V
V
V
DDQ
DDQ
DDQ
DDQ
DDQ
DDQ
DDQ
V
SS
SS
Q16 D15 D7
Q15 D6 Q6
D14 Q14 Q5
Q13 D13 D5
V
DDQ
V
REF
D12 Q4 D4
Q12 D3 Q3
D11 Q11 Q2
D10 Q1 D2
ZQ
P Q35 D35 Q26 A A C A A Q9 D0 Q0
R TDO TCK A A A C AAATMSTDI
Document Number: 001-00436 Rev. *E Page 5 of 30
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CY7C1510KV18, CY7C1525KV18 CY7C1512KV18, CY7C1514KV18

Pin Definitions

Pin Name I/O Pin Description
D
[x:0]
WPS Input-
NWS
,
0
NWS
1
BWS
,
0
BWS
,
1
,
BWS
2
BWS
3
A Input-
Q
[x:0]
RPS Input-
C Input Clock Positive Input Clock for Output Data. C is used in conjunction with C
C
K Input Clock Positive Input Clock Input. The rising edge of K is used to capture synchronous inputs to the device
K
Input-
Synchronous
Data Input Signals. Sampled on the rising edge of K and K clocks during valid write operations. CY7C1510KV18 D CY7C1525KV18 D CY7C1512KV18 D CY7C1514KV18 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
Synchronous
Input-
Synchronous
write operation is initiated. Deasserting deselects the write port. Deselecting the write port ignores D Nibble Write Select 0, 1 Active LOW (CY7C1510KV18 Only). Sampled on the rising edge of the K
and K
clocks during write operations. Used to select which nibble is written into the device during the current portion of the write operations. Nibbles not written remain unaltered. NWS0 controls D All the Nibble Write Selects are sampled on the same edge as the data. Deselecting a Nibble Write Select
and NWS1 controls D
[3:0]
[7:4].
ignores the corresponding nibble of data and it is not written into the device.
Input-
Synchronous
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 which byte is written into the device during the current portion of the write operations. Bytes not written remain unaltered. CY7C1525KV18 BWS CY7C1512KV18 BWS0 controls D CY7C1514KV18 BWS0 controls D D
[35:27].
All the Byte Write Selects are sampled on the same edge as the data. Deselecting a Byte Write Select
controls D
0
[8:0].
and BWS1 controls D
[8:0]
, BWS1 controls D
[8:0]
[17:9].
, BWS2 controls D
[17:9]
and BWS3 controls
[26:18]
ignores the corresponding byte of data and it is not written into the device.
Synchronous
Address Inputs. Sampled on the rising edge of the K (read address) and K active read and write operations. These address inputs are multiplexed for both read and write operations.
(write address) clocks during
Internally, the device is organized as 8M x 8 (2 arrays each of 4M x 8) for CY7C1510KV18, 8M x 9 (2 arrays each of 4M x 9) for CY7C1525KV18, 4M x 18 (2 arrays each of 2M x 18) for CY7C1512KV18, and 2M x 36 (2 arrays each of 1M x 36) for CY7C1514KV18. Therefore, only 22 address inputs are needed to access the entire memory array of CY7C1510KV18 and CY7C1525KV18, 21 address inputs for CY7C1512KV18, and 20 address inputs for CY7C1514KV18. These inputs are ignored when the appro­priate port is deselected.
Output-
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 the C and C clock mode. When the read port is deselected, Q CY7C1510KV18 Q CY7C1525KV18 Q CY7C1512KV18 Q CY7C1514KV18 Q
[7:0] [8:0] [17:0] [35:0]
clocks during read operations, or K and K when in single
are automatically tristated.
[x:0]
Read Port Select Active LOW. Sampled on the rising edge of positive input clock (K). When active, a
Synchronous
read operation is initiated. Deasserting deselects the read port. When deselected, the pending access is allowed to complete and the output drivers are automatically tristated following the next rising edge of the C clock. Each read access consists of a burst of two sequential transfers.
to clock out the read data from
the device. Use C and C
together to deskew the flight times of various devices on the board back to the
controller. See Application Example on page 9 for further details.
Input Clock Negative Input Clock for Output Data. C is used in conjunction with C to clock out the read data from
the device. Use C and C
together to deskew the flight times of various devices on the board back to the
controller. See Application Example on page 9 for further details.
and to drive out data through Q edge of K.
when in single clock mode. All accesses are initiated on the rising
[x:0]
Input Clock Negative Input Clock Input. K is used to capture synchronous inputs being presented to the device and
to drive out data through Q
when in single clock mode.
[x:0]
[x:0]
.
Document Number: 001-00436 Rev. *E Page 6 of 30
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CY7C1510KV18, CY7C1525KV18 CY7C1512KV18, CY7C1514KV18
Pin Definitions (continued)
Pin Name I/O Pin Description
CQ Echo Clock CQ Referenced with Respect to C. This is a free running clock and is synchronized to the input clock
for output data (C) of the QDR-II. In single clock mode, CQ is generated with respect to K. The timing for the echo clocks is shown in Switching Characteristics on page 23.
CQ
ZQ Input Output Impedance Matching Input. This input is used to tune the device outputs to the system data bus
DOFF
TDO Output TDO for JTAG.
TCK Input TCK Pin for JTAG.
TDI Input TDI Pin for JTAG.
TMS Input TMS Pin for JTAG.
NC N/A Not Connected to the Die. Can be tied to any voltage level.
NC/144M Input Not Connected to the Die. Can be tied to any voltage level.
NC/288M Input Not Connected to the Die. Can be tied to any voltage level.
V
REF
V
DD
V
SS
V
DDQ
Echo Clock CQ Referenced with Respect to C. This is a free running clock and is synchronized to the input clock
Input PLL Turn Off Active LOW. Connecting this pin to ground turns off the PLL inside the device. The timing
Input-
Reference
Power Supply Power Supply Inputs to the Core of the Device.
Ground Ground for the device.
Power Supply Power Supply Inputs for the Outputs of the Device.
for output data (C the echo clocks is shown in the Switching Characteristics on page 23.
impedance. CQ, CQ, and Q between ZQ and ground. Alternatively, connect this pin directly to V impedance mode. This pin cannot be connected directly to GND or left unconnected.
in the operation with the PLL turned off differs from those listed in this data sheet. For normal operation, connect this pin to a pull up through a 10 KΩ or less pull up resistor. The device behaves in QDR-I mode when the PLL is turned off. In this mode, the device can be operated at a frequency of up to 167 MHz with QDR-I timing.
Reference Voltage Input. Static input used to set the reference level for HSTL inputs, outputs, and AC measurement points.
) of the QDR-II. In single clock mode, CQ is generated with respect to K. The timing for
output impedance are set to 0.2 x RQ, where RQ is a resistor connected
[x:0]
, which enables the minimum
DDQ
Document Number: 001-00436 Rev. *E Page 7 of 30
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CY7C1510KV18, CY7C1525KV18 CY7C1512KV18, CY7C1514KV18

Functional Overview

The CY7C1510KV18, CY7C1525KV18, CY7C1512KV18, and CY7C1514KV18 are synchronous pipelined Burst SRAMs with 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 flows out through the read port. These devices multiplex the address inputs 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 and avoids any possible data contention, thereby simplifying system design. Each access consists of two 8-bit data transfers in the case of CY7C1510KV18, two 9-bit data transfers in the case of CY7C1525KV18, two 18-bit data transfers in the case of CY7C1512KV18, and two 36-bit data transfers in the case of CY7C1514KV18 in one clock cycle.
This device operates with a read latency of one and half cycles when DOFF connected to V a read latency of one clock cycle.
Accesses for both ports are initiated on the rising edge of the positive input clock (K). All synchronous input timing is refer­enced from the rising edge of the input clocks (K and K output timing is referenced to the output clocks (C and C and K
All synchronous data inputs (D controlled by the input clocks (K and K outputs (Q rising edge of the output clocks (C and C single clock mode).
All synchronous control (RPS through input registers controlled by the rising edge of the input clocks (K and K).
CY7C1512KV18 is described in the following sections. The same basic descriptions apply to CY7C1510KV18, CY7C1525KV18, and CY7C1514KV18.

Read Operations

The CY7C1512KV18 is organized internally as two arrays of 2M x 18. Accesses are completed in a burst of two 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 is latched on the rising edge of the K clock. The address presented to the address inputs is stored in the read address register. Following the next K clock rise, the corresponding lowest order 18-bit word of data is driven onto the Q
as the output timing reference. On the subsequent rising edge
C of C, the next 18-bit data word is driven onto the Q requested data is valid 0.45 ns from the rising edge of the output clock (C and C
Synchronous internal circuitry automatically tristates the outputs following the next rising edge of the output clocks (C/C enables for a seamless transition between devices without the insertion of wait states in a depth expanded memory.

Write Operations

Write operations are initiated by asserting WPS active at the rising edge of the positive input clock (K). On the same K clock rise the data presented to D
pin is tied HIGH. When DOFF pin is set LOW or
then the device behaves in QDR-I mode with
SS
when in single clock mode).
) pass through input registers
[x:0]
) pass through output registers controlled by the
[x:0]
, WPS, BWS
). All synchronous data
, or K and K when in
[x:0]
or K and K when in single clock mode).
is latched and stored into the
[17:0]
) and all
, or K
) inputs pass
using
[17:0]
. The
[17:0]
). This
lower 18-bit write data register, provided BWS asserted active. On the subsequent rising edge of the negative
are both
[1:0]
input clock (K), the address is latched and the information presented to D provided BWS are then written into the memory array at the specified location.
is also stored into the write data register,
[17:0]
are both asserted active. The 36 bits of data
[1:0]
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 CY7C1512KV18. A write operation is initiated as described in the Write Operations section. The bytes that are written are determined by BWS
, which are sampled with each set of 18-bit data words.
BWS
1
Asserting the appropriate Byte Write Select input during the data
and
0
portion of a write latches the data being presented and writes it into the device. Deasserting the Byte write select input during the data portion of a write enables the data stored in the device for that byte to remain unaltered. This feature is used to simplify read, modify, or write operations to a byte write operation.

Single Clock Mode

The CY7C1510KV18 is used with a single clock that controls both the input and output registers. In this mode the device recognizes only a single pair of input clocks (K and K
) that control both the input and output registers. This operation is identical to the operation if the device had zero skew between the K/K and C/C
clocks. All timing parameters remain the same in this mode.
To use this mode of operation, the user must tie C and C
HIGH at power on. This function is a strap option and not alterable during device operation.

Concurrent Transactions

The read and write ports on the CY7C1512KV18 operate completely independently of one another. As 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. The user can start reads and writes in the same clock cycle. If the ports access the same location at the same time, the SRAM delivers the most recent information associated with the specified address location. This includes forwarding data from a write cycle that was initiated on the previous K clock rise.

Depth Expansion

The CY7C1512KV18 has a port select input for each port. This enables for easy depth expansion. Both port selects are sampled on the rising edge of the positive input clock only (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
Document Number: 001-00436 Rev. *E Page 8 of 30
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CY7C1510KV18, CY7C1525KV18 CY7C1512KV18, CY7C1514KV18

Echo Clocks

R = 250ohms
Vt
R
R = 250ohms
Vt
Vt
R
Vt = Vddq/2
R = 50ohms
R
CC#
D A
SRAM #2
R P S #
W
P S #
B
W
S #
ZQ
CQ/CQ#
Q
K#
CC#
D A
K
SRAM #1
R P S #
W
P S #
B
W
S #
ZQ
CQ/CQ#
Q
K#
BUS
MASTER
(CPU
or
ASIC)
DATA IN
DATA OUT
Address
RPS# WPS# BWS#
Source K
Source K#
Delayed K
Delayed K#
CLKIN/CLKIN#
K
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 C and CQ is referenced with respect to C
. These are free running clocks and are synchro­nized to the output clock of the QDR-II. In the single clock mode, CQ is generated with respect to K and CQ respect to K
. The timing for the echo clocks is shown in Switching
is generated with
Characteristics on page 23.

Application Example

Figure 1 shows two QDR-II used in an application.
Figure 1. Application Example
PLL
These chips use a PLL that is designed to function between 120 MHz and the specified maximum clock frequency. During power up, when the DOFF is tied HIGH, the PLL is locked after 20 μs of stable clock. The PLL can also be reset by slowing or stopping the input clocks K and K However, it is not necessary to reset the PLL to lock to the desired frequency. The PLL automatically locks 20 μs after a stable clock is presented. The PLL may be disabled by applying ground to the DOFF pin. When the PLL is turned off, the device behaves in QDR-I mode (with one cycle latency and a longer access time).
for a minimum of 30 ns.
Document Number: 001-00436 Rev. *E Page 9 of 30
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