74HC595 的实际应用与编程 -

本文引用地址: http://www.21ic.com/app/mcu/201806/761730.htm

;创作日期：2007/08/012
;创作者：给我一支烟
;================================================

SDATA_595EQUP1.0 ;串行数据输入
SCLK_595 EQUP1.1 ;移位时钟脉冲
RCK_595EQUP1.2 ;输出锁存器控制脉冲

;================================================

ORG0000H
LJMPMAIN
ORG0030H

;================================================
MAIN:
MOVSP,#60H
MOVR0,#0FEH
MAIN1:
CALL OUT_595
CALLDELAY
MOVA,R0
RLA
MOVR0,A
JMPMAIN1
;---------------------------------------------------------------
;输出锁存器输出数据子程序
;---------------------------------------------------------------
OUT_595:
LCALL WR_595
CLRRCK_595
NOP
NOP
SETB RCK_595;上升沿将数据送到输出锁存器
NOP
NOP
NOP
CLRRCK_595
RET
;--------------------------------------------------------------
;移位寄存器接收数据子程序
;--------------------------------------------------------------
WR_595:
MOV R4,#08H
MOV A,R0
WR_LOOP:
RLC A
MOV SDATA_595,C
SETB SCLK_595 ;上升沿发生移位
NOP
NOP
CLR SCLK_595
DJNZ R4,WR_LOOP
RET
;--------------------------------------------------------------
;延时子程序
;--------------------------------------------------------------
DELAY:
MOVR5,#03H
DEL0:
MOVR6,#0FFH
DEL1:
MOVR7,#0FFH
DJNZR7,$
DJNZR6,DEL1
DJNZR5,DEL0
RET
;---------------------------------------------------------------
END