Expandable data width SAM for a multiport RAM

摘要

A multiport memory is described which includes a random access memory (RAM) and serial access memories (SAMs). The multiport memory is well suited for storing asynchronous transfer mode (ATM) data cells. Control circuitry is provided to allow the multiport memory to be easily configured for operating at different input data rates. This is accomplished by configuring several of the SAMs to store a portion of an input ATM cell on an input clock cycle. The full ATM cell is stored in less clock cycles and can be transferred from the SAMs to the RAM in a single transfer cycle.