The next silicon feature is the IPC message registers. These registers provide a very simple and flexible messaging scheme and can be used like a mailbox to send messages back and forth. These are dedicated registers and are mapped to both CPU’s. They have been named IPCCOMMAND, IPCADDR, IPCDATAWRITE, and IPCDATAREAD; however, the definition of what the registers’ contents mean is actually up to the application software. TI’s IPC-Lite drivers use the IPC message registers. This software is described in part two of this topic in the next training.