Hi Franc,

40µs was also a long time in the 8051 world. E.g. the nice little 87LPC764 can do up to 133 instructions during this time.

But the other point, the nice little 87LPC764 can execute up to 4kB code, which was fully unable for the similiar little AT90S2313 (need about 6kB to do the same).

And shooting always with the big and expensive cannon Mega103 was not economical.


Peter

P.S.:
You can E-Mail me the interrupt routine (C or assembler) and I can check, if it was executable for an 8051. In any case the code space consumption shrink.