I'm trying to find a means of producing a pseudo-random s 8-bit values in AVR assembly (ATmega) using as few processor cycles as possible.
I'm aware of LFSR-type approaches, but even for an 8-bit value, these would be too slow (for a Galois configuration, I estimate around 50 cycles). If possible, something in the region of 5 cycles would be ideal.
For up to 10000 iterations, I'd be looking for the algorithm to produce fairly white noise. Use of some sort of LUT is practical as long as it is fairly small (16 bytes?), I'm really pushed for program space and CPU time on this one!
Is what I'm asking totally unrealistic? Any ideas greatly appreciated.