HM534253B Datasheet, PDF (1/45 Pages) Elpida Memory – 1 M VRAM (256-kword x 4-bit)

HM534253B Series
1 M VRAM (256-kword × 4-bit)
E0165H10 (Ver. 1.0)
(Previous ADE-203-204D (Z))
Jul. 6, 2001 (K)
Description
The HM534253B is a 1-Mbit multiport video RAM equipped with a 256-kword × 4-bit dynamic RAM and a
512-word × 4-bit SAM (serial access memory). Its RAM and SAM operate independently and
asynchronously. It can transfer data between RAM and SAM. In addition, it has two modes to realize fast
writing in RAM. Block write and flash write modes clear the data of 4-word × 4-bit and the data of one row
(512-word × 4-bit) respectively in one cycle of RAM. And the HM534253B makes split transfer cycle
possible by dividing SAM into two split buffers equipped with 256-word × 4-bit each. This cycle can transfer
data to SAM which is not active, and enables a continuous serial access.
Features
• Multiport organization
Asynchronous and simultaneous operation of RAM and SAM capability
 RAM: 256-kword × 4-bit
 SAM: 512-word × 4-bit
• Access time
 RAM: 60 ns/70 ns/80 ns/100 ns max
 SAM: 20 ns/22 ns/25 ns/25 ns max
• Cycle time
 RAM: 125 ns/135 ns/150 ns/180 ns min
 SAM: 25 ns/25 ns/30 ns/30 ns min
• Low power
 Active RAM: 413 mW max
SAM: 275 mW max
 Standby 38.5 mW max
• High-speed page mode capability
• Mask write mode capability
• Bidirectional data transfer cycle between RAM and SAM capability
• Split transfer cycle capability
Elpida Memory, Inc. is a joint venture DRAM company of NEC Corporation and Hitachi, Ltd.