Accutek
Microcircuit
Corporation
DESCRIPTION
The Accutek AK48256 high density memory modules is a random
access memory organized in 256K x 8 bit words. The assembly
consists of eight standard 256K x 1 DRAMs in plastic leaded chip
carriers (PLCC) mounted on the front side of a printed circuit board.
The module can be configured as a leadless 30 pad SIM or a leaded
30 pin SIP. This packaging approach provides a 6 to 1 density in-
crease over standard DIP packaging.
The operation of the AK48256 is identical to eight 256K x 1 DRAMs.
The data input is tied to the data output and brought out separately
for each device, with common RAS, CAS and WE control. This
common I/O feature dictates the use of early-write cycles to prevent
contention of D and Q. Since the Write-Enable (WE) signal must al-
ways go low before CAS in a write cycle, Read-Write and
Read-Modify-Write operation is not possible.
AK48256S / AK48256G
262,144 X 8 Bit MOS
Dynamic Random Access Memory
Front View
30-Pin SIM
1
30
30-Pin SIP
1
FEATURES
·
262,144 by 8 bit organization
·
Optional 30 Pad leadless SIM (Single In-Line Module) or 30
Pin leaded SIP (Single In-Line Package)
·
JEDEC standard pinout
·
Each device has common D and Q lines with common RAS,
CAS and WE control
·
2.8 Watt active and 180 mW standby (max)
·
Operating free air temperature 0
0
C to 70
0
C
·
Upward compatible with AK481024, AK581024, AK584096 and
AK5816384
·
Functionally and Pin compatible with AK58256A
PIN NOMENCLATURE
A
0
- A
8
DQ
1
- DQ
8
CAS
RAS
WE
Vcc
Vss
NC
Address Inputs
Data In / Data Out
Column Address Strobe
Row Address Strobe
Write Enable
5v Supply
Ground
No Connect
PIN ASSIGNMENT
PIN #
SYMBOL
PIN #
SYMBOL
FUNCTIONAL DIAGRAM
DQ5
A8
NC
NC
DQ6
WE
Vss
DQ7
NC
DQ8
NC
RAS
NC
NC
Vcc
1
2
3
4
5
6
7
8
9
10
11
Vcc
CAS
DQ!
A0
A1
DQ2
A2
A3
Vss
DQ3
A4
A5
DQ4
A6
A7
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
MODULE OPTIONS
Leadless SIM: AK48256S
Leaded SIP: AK48256G
12
13
14
15
ACCUTEK [ ACCUTEK MICROCIRCUIT CORPORATION ]
