PIC Microcontoller Radix Math Method

ASCII hexadecimal to Binary

by: Peter F.

After looking at the conversion routines above, I figured I'd add my own. Note this routine does no error checking on the ascii input characters. Peter F. tsetsetse at hotmail.com

;convert 2 hex ascii characters to an 8-bit value 
;ascii stored in hichar/lochar, result returned in w 
;hichar/lochar are unchanged 
ascii2byte 
	swapf hichar,w	;swap hi nibble into result
	btfsc hichar,6	;check if in range 'A'-'F' 
	addlw 0x8F 	;add correction swapf ('1'-'A'+1) 
	addwf lochar,w 	;add lo nibble 
	btfsc lochar,6 	;check if in range 'A'-'F' 
	addlw 0xF9 	;add correction '9'-'A'+1
	addlw 0xCD 	;adjust final result -0x33 
	return 

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