DOUBLE PORT TIMING CONTROLLER

摘要

A shared random access memory (S-RAM) can be accessed either by a local processor (18) or a host processor (595) which, in a preferred configuration, controls an integrated circuit integrated services data protocol controller. The DPTC provides control signals allowing an ordinary RAM to be operated as an S-RAM. The DPTC includes a semaphore register (596) that stores bidirectional interprocessor interrupts, enabling passing of high level messages between the local and host processors.