Hello,

I'm currently involved with a university research group designing an asynchronous 8051-compatible microcontroller. We're currently trying to gather information on typical usage of the processor, and the style of code used. (For optimizing internal processor pathways, etc).

So, seeing this forum, I decided I might as well ask and see if I could get some useful additional data.

1. How often are hard-coded delay loops used in 8051 code? As in, not using timers, but relying on the execution time of, say, a string of NOPs, for delays. (An issue because an asynchronous design does not guarantee uniform execution time) How often does code implicity rely on steady execution timing to work?

2. What opcodes tend to be the most frequent in 8051 code? We're obtaining and analyzing actual 8051 code, as well, but I'd like to see if anyone has any previous knowledge on the subject.

3. Related to the above, we're looking for assembly sources for large 8051 programs, preferably ones that do not interact with the outside world in complicated ways (makes our analysis simulations more complicated to write). If anyone has good pointers to such sites (besides what's listed here on this website), I'd appreciate it.

Thanks,

Eino-Ville Talvala
Caltech