Shared memory between hardware and uClinux

IMHO, you in fact should create an Avalon bus master module (aka DMA) that reads memory data words from memory and writes them to the DACs.

Why do you think that there is a problem with external memory ? Your Module just accesses the Avalon bus with the appropriate address. AFAIK the Avalon bus design automatically handles bus conflicts.

You need to take care that the shared memory region is accessed with the CPU without the cache. When doing the appropria<te Linux device driver, the system offers macros to access "DMA-Memory" for that purpose. (NIOS nommu hardware handles this very different from NIOS mmu, but the Kernel should take care of this.)

-Michael