Y7C1032
WCSS0418V1F
256K x 18 Synchronous
3.3V Cache RAM
Features
• Supports 117-MHz microprocessor cache systems with
zero wait states
• 256K by 18 common I/O
• Fast clock-to-output times
— 7.5 ns (117-MHz version)
• Two-bit wrap-around counter supporting either inter-
leaved or linear burst sequence
• Separate processor and controller address strobes
provide direct interface with the processor and external
cache controller
• Synchronous self-timed write
• Asynchronous output enable
• I/Os capable of 2.5–3.3V operation
• JEDEC-standard pinout
• 100-pin TQFP packaging
• ZZ “sleep” mode
Functional Description
The WCSS0418V1F is a 3.3V, 256K by 18 synchronous cache
RAM designed to interface with high-speed microprocessors
with minimum glue logic. Maximum access delay from clock
rise is 7.5 ns (117-MHz version). A 2-bit on-chip counter cap-
tures the first address in a burst and increments the address
automatically for the rest of the burst access.
The allows WCSS0418V1F both interleaved or linear burst se-
quences, 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.
A synchronous self-timed write mechanism is provided to sim-
plify the write interface. A synchronous chip enable input and
an asynchronous output enable input provide easy control for
bank selection and output three-state control.
Logic Block Diagram
CLK
ADV
ADSC
ADSP
A
[17:0]
GW
BWE
BW
1
MODE
(A
0
,A
1
) 2
BURST Q
0
CE COUNTER
Q
1
CLR
Q
ADDRESS
CE REGISTER
D
16
18
18
16
256K X 18
MEMORY
ARRAY
D
Q
DQ[15:8]
BYTEWRITE
REGISTERS
Q
DQ[7:0]
BYTEWRITE
REGISTERS
D
BW
0
CE
1
CE
2
CE
3
D
ENABLE Q
CE REGISTER
CLK
18
18
INPUT
REGISTERS
CLK
OE
ZZ
SLEEP
CONTROL
DQ
[15:0]
DP
[1:0]
Selection Guide
WCSS0418V1F-117
Maximum Access Time (ns)
Maximum Operating Current (mA)
Maximum Standby Current (mA)
Intel and Pentium are registered trademarks of Intel Corporation.
WCSS0418V1F-100
8.0
325
10.0
7.5
350
10.0
Document #: 38-05245 Rev. **
Revised Jan 05,2002
WEIDA [ WEIDA SEMICONDUCTOR, INC. ]
