mc8051fun/bcd_tolong__.c

#include "usebank0.h"
/*
r0 = bcd
r1 = bin
r7 = len of bcd
r6 = len of bin


reverse double dabble
*/
 
static void bcd_tolong__() __naked
{

	__asm

	.globl	bcd_tolong
bcd_tolong:
	mov	a,AR6		; use r4 as counter
	mov	b,#0x08
	mul	ab
	mov	r4,a


000$:
	push	AR0
	push	AR7
	clr	c

	lcall	long_rrc
	mov	r0,AR1
	mov	r7,AR6

	lcall	long_rrc
	pop	AR7
	pop	AR0
	push	AR0
	push 	AR7
	
001$:
	mov	a,@r0
	acall	003$
	acall	003$
	mov	@r0,a

	inc 	r0
	djnz	r7,001$
	pop	AR7
	pop	AR0
	djnz	r4,000$
	ret				
003$:
	swap	a
	clr	c
	subb	a,#0x80
	jc	002$
	subb	a,#0x30
002$:
	add	a,#0x80
	ret
	
	__endasm;

}