WED8L24257V
Asynchronous SRAM, 3.3V, 256Kx24
FEATURES
256Kx24 bit CMOS Static
Random Access Memory Array
鈥?Fast Access Times: 10, 12, and 15ns
鈥?Master Output Enable and Write Control
鈥?TTL Compatible Inputs and Outputs
鈥?Fully Static, No Clocks
Surface Mount Package
鈥?119 Lead BGA (JEDEC MO-163), No. 391
鈥?Small Footprint, 14mmx22mm
鈥?Multiple Ground Pins for Maximum Noise Immunity
Single +3.3V (鹵5%) Supply Operation
DSP Memory Solution
鈥?Motorola DSP5630x
鈥?Analog Devices SHARC
TM
The JEDEC Standard 119 lead BGA provides a 69% space savings
over using six 256Kx4, 300 mil wide SOJs and the BGA package
has a maximum height of 110 mils compared to 148 mils for the SOJ
packages. The BGA package also allows the use of the same
manufacturing and inspection techniques as the Motorola DSP, which
is also in a BGA package.
The single or dual chip memory solutions offer improved system
performance by reducing the length of board traces and the number
of board connections compared to using multiple monolithic devices.
DESCRIPTION
The WED8L24257VxxBC is a 3.3V, twelve megabit SRAM con-
structed with three 256Kx8 die mounted on a multi-layer laminate
substrate. With 10 to 15ns access times, x24 width and a 3.3V
operating voltage, the WED8L24257V is ideal for creating a single chip
memory solution for the Motorola DSP5630x (Figure 8) or a two chip
solution for the Analog Devices SHARC
TM
DSP (Figure 9).
FIG. 1
PIN CONFIGURATION
PIN SYMBOLS
1
2
AO
A5
NC
VCC
GND
VCC
GND
VCC
GND
VCC
GND
VCC
GND
VCC
NC
A9
A13
3
A1
A6
NC
GND
VCC
GND
VCC
GND
VCC
GND
VCC
GND
VCC
GND
NC
A10
A14
4
A2
E
NC
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
NC
W
G
5
A3
A7
NC
GND
VCC
GND
VCC
GND
VCC
GND
VCC
GND
VCC
GND
NC
A11
A15
6
A4
A8
NC
VCC
GND
VCC
GND
VCC
GND
VCC
GND
VCC
GND
VCC
A17
A12
A16
7
NC
NC
I/00
I/01
I/02
I/03
I/04
I/05
NC
I/06
I/07
I/08
I/09
I/010
I/011
NC
NC
A
0-17
E
W
G
DQ
0-23
VCC
GND
NC
PIN NAMES
Address Inputs
Chip Enable
Master Write Enable
Master Output Enable
Common Data Input/Output
Power (3.3V
鹵5%)
Ground
No Connection
A
B
C
D
E
F
G
H
J
K
L
M
N
P
R
T
U
NC
NC
I/012
I/013
I/014
I/015
I/016
I/017
NC
I/018
I/019
I/020
I/021
I/022
I/023
NC
NC
BLOCK DIAGRAM
A
0
-A
17
G
W
E
18
256K x 24
Memory
Array
DQ
0
-
7
DQ
8-15
DQ
16-23
March 2000 Rev. 1
ECO #12474
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White Electronic Designs Corporation 鈥?(508) 366-5151 鈥?www.whiteedc.com
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