DESCRIPTION

The MSM514252A is an 1-Mbit CMOS multiport DRAM composed of a 262,144-word by 4-bit dynamic RAM, and a 512-word by 4-bit static serial access memory, SAM port. The RAM port and SAM port operate independently and asynchronously.

The MSM514252A supports three types of operations: random access to and from the RAM port, high speed serial access to and from the SAM port and bidirectional transfer of data between any selected row in the RAM port and the SAM port. The RAM port and the SAM port can be accessed independently except when data is being transferred between them internally.

FEATURES

• Single power supply of 5 V ±10 with a built-in VBB generator

• All inputs and outputs: TTL compatible

• Multiport organization

RAM port: 256K word x 4 bits

SAM port: 512 word x 4 bits

• RAM port

Fast page mode, Read-modify-write

CAS before RAS refresh, Hidden refresh

RAS only refresh, Standard write-per-bit

• SAM port

High speed serial

Read/Write capability

Fully static register

512 tap location

• RAM-SAM bidirectional, Read/Write/Pseudo write, Real time read transfer

• Package options:

28-pin 400 mil plastic ZIP (ZIP28-P-400-1.27) (Product : MSM514252A-xxZS)

28-pin 400 mil plastic SOJ (SOJ28-P-400-1.27) (Product : MSM514252A-xxJS)

xx indicates speed rank.