fax id: 5208
1CY 7B1 46
CY7B136
CY7B146
2K x 8 Dual-Port Static RAM
Features
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0.8-micron BiCMOS for high performance
Automatic power-down
TTL compatible
Capable of withstanding greater than 2001V electrostatic discharge
Fully asynchronous operation
Master CY7B136 easily expands data bus width to 16
or more bits using slave CY7B146
BUSY output flag on CY7B136; BUSY input on CY7B146
INT flag for port-to-port communication
Functional Description
The CY7B136 and CY7B146 are high-speed BiCMOS 2K by
8 dual-port static RAMS. Two ports are provided to permit independent access to any location in memory. The CY7B136
can be utilized as either a standalone 8-bit dual-port static
RAM or as a MASTER dual-port RAM in conjunction with the
CY7B146 SLAVE dual-port device in systems requiring 16-bit
or greater word widths. It is the solution to applications requiring shared or buffered data such as cache memory for DSP,
bit-slice, or multiprocessor designs.
Each port has independent control pins; chip enable (CE),
write enable (R/W), and output enable (OE). BUSY flags are
provided on each port. In addition, an interrupt flag (INT) is
provided on each port. BUSY signals that the port is trying to
access the same location currently being accessed by the other port. The INT is an interrupt flag indicating that data has
been placed in a unique location (7FF for the right port and
7FE for the left port).
An automatic power-down feature is controlled independently
on each port by the chip enable (CE) pins.
The CY7B136/CY7B146 are available in 52-lead PLCC.
Logic Block Diagram
R/W L
CE L
R/WR
CE R
OE L
A10L
OER
A10R
A7L
I/O0L
A7R
I/O 0R
COL
SEL
I/O 7L
BUSYL
COLUMN
I/O
COLUMN
I/O
I/O 7R
[1]
[1]
BUSYR
A6L
MEMORY
ARRAY
ROW
SELECT
A0L
ROW
SELECT
BUSYL
[2]
A0L
CE L
OE L
R/WL
A6R
A0R
A10R
A10L
INT L
COL
SEL
ARBITRATION
LOGIC
(7B136 ONLY)
AND
INTERRUPTLOGIC
A0R
CER
OER
R/W
R
BUSYR
INT R
[2]
B136-1
Notes:
1. CY7B136 (Master): BUSY an open drain output and requires a pull-up resistor.
CY7B146 (Slave): BUSY is an input.
2. Open drain outputs; pull-up resistor required
Cypress Semiconductor Corporation
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3901 North First Street
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San Jose
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CA 95134 •
408-943-2600
June 1995 – Revised July 1995
