delayms.a51

来自「USB2.0原理与工程开发光盘(第二版)」· A51 代码 · 共 40 行

$NOMOD51  
NAME		DELAY1MS
PUBLIC		DELAY1MS, EZUSB_SUSP

$include (testregs.inc)

EZUSB		segment	code
EZUSB1		segment	code

		rseg	EZUSB		
DELAY1MS:
		mov	a, #0		
		mov	dps, a		
		mov	dptr,#(0ffffH - 602) 

loop:	     	inc     dptr          
		mov     a,dpl       
                orl     a,dph        
                jnz     loop	
er_end:		ret

		rseg	EZUSB1		
EZUSB_SUSP:	mov	dptr,#USBCS
		movx	a,@dptr	
		orl	a,#80h
		movx	@dptr,a

		orl	PCON,#00000001b		

		nop		
		nop		
		nop		
		nop
		nop

er_end1:	ret                

                end