Using custom instruction from uCLinux user app on nios2mmu

If you are going to do that, I'd make require the software have to wait itself - then you can use a combinatorial custom instruction and avoid the register file delays on the read value.

You could also use the 'rB' field as a sub-opcode (set poly, new value etc).

In my case I was doing 64 channels of hdlc from a TDM stream - so had individual bytes to process.

If you have a buffer, then you want a dma based engine....