Multiprosessor Nios systems

Mike,

Great protocol. Almost exactly what we do on our dual Coldfire board, but we use a physical DPR that generates the interrupts and provides the mailbox.

I didn't want to use IRQ's in this design because I need the second processors ISR latency for its most important task to be as jitter free as possible. I've found with the LA that IRQ activity increases jitter even for the highest priority ISR's.

In my case the second processor can check for new messages whenever its convenient because command response latency of several ms is fine.

hassu3,

Mike's IRQ approach would really just tell the processor it was time to check his mail. You still may need the mailbox or something like it to transfer commands and data.

Ken