DESCRIPTION
The MSM518121A is an 1-Mbit CMOS multiport memory composed of a 131,072-words by 8-bit dynamic random access memory, RAM port, and a 256-word by 8-bit static serial access memory, SAM port. The RAM port and SAM port operate independently and asynchronously.
The MSM518121A supports three types of operation: 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 : 128K word x 8 bits
    SAM port : 256 word x 8 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 capabillity
    Fully static register
    256 tap location
• RAM-SAM bidirectional, Read / Write / Pseudo write, Real time read transfer
• Package options:
    40-pin 475 mil plastic ZIP (ZIP40-P-475-1.27) (Product : MSM518121A-xxZS)
    40-pin 400 mil plastic SOJ (SOJ40-P-400-1.27) (Product : MSM518121A-xxJS)
                                                                                xx indicates speed rank.