EO
Description
Features
HM538253B Series
HM538254B Series
2 M VRAM (256-kword
×
8-bit)
Hyper Page Mode (HM538254B)
The HM538253B/HM538254B is a 2-Mbit multiport video RAM equipped with a 256-kword
×
8-bit dynamic
RAM and a 512-word
×
8-bit SAM (full-sized SAM). Its RAM and SAM operate independently and
asynchronously. The HM538253B/HM538254B is upwardly compatible with the HM534253B/HM538123B
except that the pseudo-write-transfer cycle is replaced with masked-write-transfer cycle, which has been
approved by JEDEC. Furthermore, several new features have been added to the HM538253B/HM538254B
which do not conflict with the conventional features. The stopping column feature realizes allows greater
flexibility for split SAM register lengths. Persistent mask is also installed according to the TMS34020
features. The HM538254B has Hyper page mode which enables fast page cycle.
•
Multiport organization:RAM and SAM can operate asynchronously and simultaneously:
RAM: 256-kword
×
8-bit
SAM: 512-word
×
8-bit
•
Access time
RAM: 70 ns/80 ns/100 ns max
SAM: 20 ns/23 ns/25 ns max
•
Cycle time
RAM: 130 ns/150 ns/180 ns min
SAM: 25 ns/28 ns/30 ns min
•
Low power
Active
RAM: 605 mW/550 mW/495 mW
SAM: 358 mW/330 mW/303 mW
Standby 38.5 mW max
•
Masked-write-transfer cycle capability
•
Stopping column feature capability
•
Persistent mask capability
Elpida Memory, Inc. is a joint venture DRAM company of NEC Corporation and Hitachi, Ltd.
LP
E0163H10 (Ver. 1.0)
(Previous ADE-203-264A/265 (Z))
Jul. 6, 2001 (K)
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HM538253B/HM538254B Series
•
Fast page mode capability (HM538253B)
Cycle time:
45 ns/50 ns/55 ns
Power RAM:
605 mW/578 mW/550 mW
•
Hyper page mode capability (HM538254B)
Cycle time:
35 ns/40 ns/45 ns
Power RAM:
715 mW/660 mW/605 mW
•
Mask write mode capability
•
Bidirectional data transfer cycle between RAM and SAM capability
•
Split transfer cycle capability
•
Block write mode capability
•
Flash write mode capability
•
3 variations of refresh (8 ms/512 cycles)
RAS-only
refresh
CAS-before-RAS
refresh
Hidden refresh
•
TTL compatible
EO
Type No.
HM538253BJ-7
HM538253BJ-8
HM538253BJ-10
HM538254BJ-7
HM538254BJ-8
HM538254BJ-10
HM538253BTT-7
HM538253BTT-8
HM538253BTT-10
HM538254BTT-7
HM538254BTT-8
HM538254BTT-10
2
Ordering Information
LP
Access Time
70 ns
80 ns
100 ns
70 ns
80 ns
100 ns
70 ns
80 ns
100 ns
70 ns
80 ns
100 ns
Data Sheet E0163H10
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Package
400-mil, 40-pin plastic SOJ (CP-40D)
44-pin thin small outline package (TTP-44/40DA)
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HM538253B/HM538254B Series
Pin Description
Pin Name
A0-A8
EO
I/O0-I/O7
SI/O0-SI/O7
RAS
CAS
WE
DT/OE
SC
SE
DSF1
QSF
V
CC
V
SS
NL
NC
4
Function
Address inputs
RAM port data inputs/outputs
SAM port data inputs/outputs
Row address strobe
Column address strobe
Write enable
Data transfer/output enable
Serial clock
SAM port enable
Special function input flag
Special function output flag
Power supply
Ground
No lead
No connection
LP
Data Sheet E0163H10
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