PIC Microcontoller Delay Method

Delay X cycles (0-1024) macro by Mike Harrison

Mike Harrison [mike@WHITEWING.CO.UK] says:

While we're on the subject of inline delays, here's a handy 'delay any number of cycles' (within reason!) macro I did when messing with generating TV timings :

usage : wait n delays n cycles, n = 0 to about 1024.


shortwait macro del  ; used by main wait macro
 if (del>3) && (del<8) call del7+(7-(del)) endif if del <4 if del>=2 
  goto $+1
  endif
  if ((del) & 1) == 1
  nop
  endif
 endif
 endm

 ; main macro - generates code to wait for (del) cycles)

wait macro del 

 if (del)<0 error 'negative delay' endif if (del)>=8 
 movlw ((del)-8) /4 
 call delay
 shortwait ((del-8) % 4) 
 else
 shortwait (del)
 endif
 endm

delay  
 addlw 0ff 
 skpnc 
 goto delay
 return
 
del7 goto del5  ; 7 cycle delay
del6 goto del4  ; 6 cycle delay
del5 nop           ; 5 cycle delay
del4 return       ; 4 cycle delay