CY7C1325G
4-Mbit (256K x 18) Flow-Through Sync SRAM
Features
Functional Description[1]
• 256K x 18 common I/O
The CY7C1325G is a 256 K x 18 synchronous cache RAM
designed to interface with high-speed microprocessors with
minimum glue logic. Maximum access delay from clock rise is
• 3.3V core power supply (VDD
)
• 2.5V or 3.3V I/O power supply (VDDQ
)
6.5 ns (133-MHz version). A 2-bit on-chip counter captures the
first address in a burst and increments the address automati-
cally for the rest of the burst access. All synchronous inputs
are gated by registers controlled by a positive-edge-triggered
Clock Input (CLK). The synchronous inputs include all
addresses, all data inputs, address-pipelining Chip Enable
(CE1), depth-expansion Chip Enables (CE2 and CE3), Burst
Control inputs (ADSC, ADSP, and ADV), Write Enables
(BW[A:B], and BWE), and Global Write (GW). Asynchronous
inputs include the Output Enable (OE) and the ZZ pin.
• Fast clock-to-output times
— 6.5 ns (133-MHz version)
• Provide high-performance 2-1-1-1 access rate
• User-selectable burst counter supporting Intel®
Pentium® interleaved or linear burst sequences
• Separate processor and controller address strobes
• Synchronous self-timed write
The CY7C1325G allows either interleaved or linear burst
sequences, selected by the MODE input pin. A HIGH selects
an interleaved burst sequence, while a LOW selects a linear
burst sequence. Burst accesses can be initiated with the
Processor Address Strobe (ADSP) or the cache Controller
Address Strobe (ADSC) inputs.
• Asynchronous output enable
• Available in lead-free 100-Pin TQFP package, lead-free
and non-lead-free 119-Ball BGA package
• “ZZ” Sleep Mode option
Addresses and chip enables are registered at rising edge of
clock when either Address Strobe Processor (ADSP) or
Address Strobe Controller (ADSC) are active. Subsequent
burst addresses can be internally generated as controlled by
the Advance pin (ADV).
The CY7C1325G operates from a +3.3V core power supply
while all outputs may operate with either a +2.5 or +3.3V
supply. All inputs and outputs are JEDEC-standard
JESD8-5-compatible.
Logic Block Diagram
ADDRESS
REGISTER
A0,A1,A
A[1:0]
Q1
MODE
ADV
CLK
BURST
COUNTER AND
LOGIC
CLR
Q0
ADSC
ADSP
DQ
B,DQPB
DQ
B,DQPB
WRITE DRIVER
WRITE REGISTER
BW
B
A
MEMORY
ARRAY
OUTPUT
BUFFERS
DQs
DQP
DQP
SENSE
AMPS
A
B
DQ
A,DQPA
DQA,DQPA
WRITE REGISTER
WRITE DRIVER
BW
BWE
GW
INPUT
REGISTERS
ENABLE
REGISTER
CE
CE
CE
1
2
3
OE
SLEEP
CONTROL
ZZ
Note:
1. For best-practices recommendations, please refer to the Cypress application note System Design Guidelines on www.cypress.com.
Cypress Semiconductor Corporation
Document #: 38-05518 Rev. *D
•
198 Champion Court
•
San Jose, CA 95134-1709
•
408-943-2600
Revised July 4, 2006