CYM1441 Datasheet, PDF (1/6 Pages) Cypress Semiconductor – 256K x 8 Static RAM Module

41
Features
• High-density 2-megabit SRAM module
• High-speed CMOS SRAMs
— Access time of 20 ns
• Low active power
— 5.3W (max.)
• SMD technology
• Separate data I/O
• 60-pin ZIP package
• TTL-compatible inputs and outputs
• Low profile
— Max. height of 0.5 in.
• Small PCB footprint
— 1.14 sq. in.
Logic Block Diagram
A₀ - A₁₇
WE
CS_U
256K x 1
SRAM
256K x 1
SRAM
DI₄ - DI₇
CS_L
256K x 1
SRAM
256K x 1
SRAM
DI₀ - DI₃
CYM1441
256K x 8 Static RAM Module
Functional Description
The CYM1441 is a very high performance 2-megabit static
RAM module organized as 256K words by 8 bits. The module
is constructed using eight 256K x 1 static RAMs in SOJ pack-
ages mounted onto an epoxy laminate substrate with pins. Two
chip selects (CS_L and CS_U) are used to independently enable
the upper and lower 4 bits of the data word. Writing to the
memory module is accomplished when the chip select (CS)
and write enable (WE) inputs are both LOW. Data on the eight
input pins (DI₀ through DI₇) is written into the memory location
specified on the address pins (A₀ through A₁₇). Reading the
device is accomplished by taking chip select (CS) LOW while
write enable (WE) remains inactive or HIGH. Under these con-
ditions, the contents of the memory location specified on the
address pins will appear on the appropriate data output pins
(DO₀ through DO₇). The data output pins remain in a high-
impedance state unless the module is selected and write en-
able (WE) is HIGH.Two pins (PD₀ and PD₁) are used to identify
module memory density in applications where alternate ver-
sions of the JEDEC-standard modules can be interchanged.
256K x 1
SRAM
256K x 1
SRAM
Pin Configuration
ZIP
TopView
(OPEN)PD₀
NC
V_CC
256K x 1
SRAM
DI₀
DO₀
A₀
A₂
A₄
A₆
GND
DI₁
DO₁
DO₄ - DO₇
WE
A₉
CS_L
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
GND
PD₁ (GND)
NC
DI₄
DO₄
NC
A₁
A₃
A₅
A₇
DI₅
DO₅
V_CC
A₈
NC
256K x 1
SRAM
DO₀ - DO₃
NC
NC
V_CC
DI₂
DO₂
A₁₀
A₁₂
A₁₄
A₁₆
NC
DI₃
DO₃
NC
NC
GND
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
CS_U
NC
NC
DI₆
DO₆
GND
A₁₁
A₁₃
A₁₅
A₁₇
DI₇
DO₇
V_CC
NC
NC
Cypress Semiconductor Corporation • 3901 North First Street • San Jose • CA 95134 • 408-943-2600
Document #: 38-05271 Rev. **
Revised March 15, 2002