SX Microcontroller Radix Math Method

Binary to BCD packed 8 bit to 2 digit

From: Ken Mathis

;Purpose: Convert an 8 bit number to BCD
;so value can be sent to a 7447 seven segment display driver
;I/O pin hungry, requires 8 bits to send data out.
;temp1 holds binary value
;BCD result in temp1
;$32 (50 decimal) becomes or %01010000
hex_to_bcd
	clr		temp0	;clear register
convert
	inc		temp0	;increment number of 10’s
	mov		w,#$0A	
	sub		temp1,w	;subtract 10 from temp1
	snc			;skip next instruction if underflow occurs
	jmp		convert	;repeat
	mov		w,#$A		
	add		temp1,w	;restore temp1. number of 1’s after restored
	dec		temp0	;correction to the number of 10’s
	swap		temp0	;swap upper and lower nibble of temp0
	add		temp1,temp0	;place number of 10’s in upper nibble of temp1
	ret				;temp1 now hold BCD value of $32

Questions:

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