Rogerio Odriozola Belden <PICLIST@MITVMA.MIT.EDU> wrote:

> Hi everyone, I've never used the INCFSZ instruction; does it roll
> over to zero after 127 ? Or whats the top number before rolling to
> zero?

Rogerio:

This question is trickier than it seems...

For most registers (including all the General-Purpose Registers), the
top number is 255.

For the 16C54/55/56 FSR register, the answer is 31 (decimal), since the
upper 3 bits of the FSR are always "1".

For the 16C57 FSR register, the answer is 127, since the high bit is
always set to "1".

For the 16C5x's PORTA register, INCFSZ will increment the register
from 0 to 15 (deciaml) before it wraps back around to 0, but the
"skip" part of the INCFSZ instruction will NEVER happen, because the
upper 4 bits of the PORTA register always read as "0".

-Andy

Andrew Warren - fastfwd@ix.netcom.com
Fast Forward Engineering, Vista, California
http://www.geocities.com/SiliconValley/2499