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CY7C1297H
1-Mbit (64K x 18) Flow-Through Sync SRAM
Cypress Semiconductor Corporation • 198 Champion Court • San Jose, CA 95134-1709 • 408-943-2600
Document #: 38-05669 Rev. *B Revised July 6, 2006
Features
• 64K x 18 common I/O
• 3.3V core power supply (V
DD
)
• 2.5V/3.3V I/O power supply (V
DDQ
)
• Fast clock-to-output times
— 6.5 ns (for 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
• Asynchronous output enable
• Available in JEDEC-standard lead-free 100-Pin TQFP
package
• “ZZ” Sleep Mode option
Functional Description
[1]
The CY7C1297H is a 64K x 18 synchronous cache RAM
designed to interface with high-speed microprocessors with
minimum glue logic. Maximum access delay from clock rise is
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
(
CE
1
)
, depth-expansion Chip Enables (CE
2
and
CE
3
), 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.
The CY7C1297H 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. Address advancement is
controlled by the Address Advancement (ADV
) input.
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 CY7C1297H operates from a +3.3V core power supply
while all outputs may operate either with a +2.5V or +3.3V
supply. All inputs and outputs are JEDEC-standard
JESD8-5-compatible.
Note:
1. For best-practices recommendations, please refer to the Cypress application note System Design Guidelines on www.cypress.com.
ADDRESS
REGISTER
ADV
CLK
BURST
COUNTER AND
LOGIC
CLR
Q1
Q0
ADSC
CE
1
OE
SENSE
AMPS
MEMORY
ARRAY
ADSP
OUTPUT
BUFFERS
INPUT
REGISTERS
MODE
CE
2
CE
3
GW
BWE
A
0,A1,A
BW
B
BW
A
DQ
B
,DQP
B
WRITE REGISTER
DQ
A
,DQP
A
WRITE REGISTER
ENABLE
REGISTER
A[1:0]
DQs
DQP
A
DQP
B
DQ
B
,DQP
B
WRITE DRIVER
DQ
A
,DQP
A
WRITE DRIVER
SLEEP
CONTROL
ZZ
Logic Block Diagram
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