;******************************************
;  Description:
;	Subtract 'DPTR' From 0,
;	 Setting Carry If DPTR Underflows
;
;  Entry Requirements:
;	DPTR Has Value To Perform 2's Complement On
;
;  On Exit:
;	DPTR = 0 - DPTR
;
;  Affected:
;	PSW.CY
;
;  Stack:
;	1 Bytes
;
;  Comments:
;	None
;
UTIL_DPTR2C	
		push	acc
		clr	c
		clr	a
		subb	a,dpl	
		mov	dpl,a	
		clr	a
		subb	a,dph
		mov	dph,a
		pop	acc
		ret