31
CYM1831
64K x 32 Static RAM Module
on an epoxy laminate board with pins. Four chip selects (CS1,
CS2, CS3, and CS4) are used to independently enable the four
bytes. Reading or writing can be executed on individual bytes
or any combination of multiple bytes through proper use of
selects.
Features
• High-density 2-Mbit SRAM module
• 32-bit standard footprint supports densities from 16K
x 32 through 1M x 32
• High-speed CMOS SRAMs
— Access time of 15 ns
• Low active power
— 5.3W (max.)
Writing to each byte is accomplished when the appropriate
Chip Selects (CSN) and Write Enable (WE) inputs are both
LOW. Data on the input/output pins (I/OX) is written into the
memory location specified on the address pins (A0 through
A15).
• SMD technology
• TTL-compatible inputs and outputs
• Low profile
Reading the device is accomplished by taking the Chip Selects
(CSN) LOW and Output Enable (OE) LOW while Write Enable
(WE) remains HIGH. Under these conditions the contents of
the memory location specified on the address pins will appear
on the data input/output pins (I/OX).
— Max. height of 0.50 in.
• Small PCB footprint
— 1.2 sq. in.
The data input/output pins stay in the high-impedance state
when Write Enable (WE) is LOW or the appropriate chip se-
lects are HIGH.
Functional Description
Two pins (PD0 and PD1) are used to identify module memory
density in applications where alternate versions of the
JEDEC-standard modules can be interchanged.
The CYM1831 is a high-performance 2-Mbit static RAM mod-
ule organized as 64K words by 32 bits. This module is con-
structed from eight 64K x 4 SRAMs in SOJ packages mounted
Logic Block Diagram
Pin Configuration
ZIP/SIMM
Top View
PD - OPEN
0
GND
1
I/O
8
1
3
PD
PD - GND
2
4
6
0
1
PD
I/O
I/O
I/O
I/O
V
A –A
0
1
2
3
0
15
OE
WE
5
7
9
16
I/O
9
8
I/O
I/O
10
11
10
12
14
16
18
20
22
24
26
28
30
32
11
13
15
17
19
21
23
25
27
29
31
CC
A
0
A
A
7
1
64K x 4
SRAM
64K x 4
I/O –I/O
I/O – I/O
7
A
8
0
3
4
A
2
SRAM
4
4
4
4
4
4
4
4
A
9
I/O
I/O
I/O
I/O
12
13
14
15
I/O
I/O
I/O
I/O
4
5
6
7
CS
1
GND
64K x 4
SRAM
64K x 4
SRAM
I/O –I/O
I/O – I/O
WE
8
11
12
15
23
31
A
15
A
14
CS
2
CS
1
CS
CS
CS
2
3
4
CS
4
33
35
37
39
41
43
45
47
49
51
53
55
57
59
61
63
CS
3
34
36
38
40
42
44
46
48
50
52
54
56
58
60
62
64
NC
OE
I/O
NC
64K x 4
SRAM
64K x 4
SRAM
I/O –I/O
I/O – I/O
16
19
20
GND
24
I/O
I/O
I/O
I/O
A
A
A
16
17
I/O
I/O
I/O
25
26
27
18
19
10
11
12
A
3
64K x 4
SRAM
64K x 4
SRAM
I/O – I/O
I/O –I/O
A
28
24
27
4
5
A
V
CC
A
13
20
21
22
23
A
6
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
28
29
30
31
GND
Cypress Semiconductor Corporation
Document #: 38-05270 Rev. **
•
3901 North First Street
•
San Jose
•
CA 95134
•
408-943-2600
Revised March 15, 2002
