MSM548262 Datasheet, PDF (1/37 Pages) OKI electronic componets – 262,144-Word x 8-Bit Multiport DRAM

E2L0016-17-Y1
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MSM548262
262,144-Word ¥ 8-Bit Multiport DRAM
This version_M: _SJa_Mn.₅1₄9₈9₂8₆₂
Previous version: Dec. 1996
DESCRIPTION
The MSM548262 is a 2-Mbit CMOS multiport DRAM composed of a 262,144-word by 8-bit
dynamic RAM, and a 512-word by 8-bit SAM. Its RAM and SAM operate independently and
asynchronously.
It supports three types of operations: random access to RAM port, high speed serial access to
SAM port, and bidirectional transfer of data between any selected row in the RAM port and the
SAM port. In addition to the conventional multiport DRAM operating modes, the MSM548262
features block write, flash write functions on the RAM port and a split data transfer capability
on the SAM port. The SAM port requires no refresh operation because it uses static CMOS flip-
flops.
FEATURES
• Single power supply: 5 V ±10%
• Full TTL compatibility
• RAS only refresh
• CAS before RAS refresh
• Multiport organization
• Hidden refresh
RAM : 256K word ¥ 8 bits
• Serial read/write
SAM : 512 word ¥ 8 bits
• 512 tap location
• Fast page mode
• Bidirectional data transfer
• Write per bit
• Split transfer
• Masked flash write
• Masked write transfer
• Masked block write
• Refresh: 512 cycles/8 ms
• Package options:
40-pin 400 mil plastic SOJ
(SOJ40-P-400-1.27)
(Product : MSM548262-xxJS)
44/40-pin 400 mil plastic TSOP (Type II)(TSOPII44/40-P-400-0.80-K)(Product : MSM548262-xxTS-K)
xx indicates speed rank.
PRODUCT FAMILY
Family
MSM548262-60
MSM548262-70
MSM548262-80
Access Time
RAM SAM
60 ns 17 ns
70 ns 17 ns
80 ns 20 ns
Cycle Time
RAM SAM
120 ns 22 ns
140 ns 22 ns
150 ns 25 ns
Power Dissipation
Operating
Standby
140 mA
8 mA
130 mA
8 mA
120 mA
8 mA
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