Post by thread:fine-tuned delays (was Picstart 16b + A SNIPPET OF

>Speaking of which, I have been using a little piece of code when I have the extra ROM >space. I like it and I'll bet at least a couple of people will not have thought of >it, even though it is hardly "rocket science." > >;**************************************************************************** >; SUBROUTINE: DELAY4 thru DELAY25 >; delays of 4 to 25 clock cycles >;**************************************************************************** >DELAY25 > NOP ...etc... >DELAY5 > NOP >DELAY4 > RETLW 0 > >Just an offering to try to refocus our attention back to PICs... How about this -use macro wait(n) to delay *any* amount from 0 to 255 cycles - for 16cxx but could easily be adapted for 5x shortwait macro del 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 wait macro del ; wait for (del) cycles) 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 del7 goto del5 ; 7 cycle delay del6 goto del4 ; 6 cycle delay del5 nop ; 5 cycle delay del4 return ; 4 cycle delay delay addlw 0ff skpnc goto delay return ____ ____ _/ L_/ Mike Harrison / White Wing Logic / spam_OUTwwlTakeThisOuTnetcomuk.co.uk _/ L_/ _/ W_/ Hardware & Software design / PCB Design / Consultancy _/ W_/ /_W_/ Industrial / Computer Peripherals / Hazardous Area /_W_/