The MSM518122 supports three types of operation : 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 MSM518122 features the block write and 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.