qth2.asm

这是一个用于测试7279的键盘编码的程序

ORG 0000H
;**********HD7279***********
CS BIT P1.4
CLK BIT P1.5
DAT BIT p1.6
KEY BIT P1.7
DATA_OUT DATA 40H
DATA_IN DATA 41H
TEN DATA 42H
GEWEI DATA 43H
;**************
MAIN:MOV SP,#20H
MOV DATA_OUT,#0A4H
     LCALL SEND
     SETB CS

     MOV DATA_OUT,#0BFH
     LCALL SEND
     SETB CS

     MOV DATA_OUT,#0A4H
     LCALL SEND
     SETB CS

START:JB KEY,START
     
      MOV DATA_OUT,#15H
      LCALL SEND
      LCALL RECEIVE
      SETB CS
      MOV A,DATA_IN
MOV B,#10
DIV AB
MOV TEN,A
MOV GEWEI,B
MOV DATA_OUT,#0C8H
     LCALL SEND
MOV DATA_OUT,GEWEI
     LCALL SEND
     SETB CS
MOV DATA_OUT,#0C9H
     LCALL SEND
MOV DATA_OUT,TEN
     LCALL SEND
     SETB CS
WAIT:JNB KEY,WAIT
AJMP START
;*******************
SEND:MOV R7,#8
     CLR CS
     LCALL DELAY_50                
     MOV A,DATA_OUT
LOOP6:MOV C,ACC.7
      MOV DAT,C
      SETB CLK
      MOV DATA_OUT,A
      RL A
      LCALL DELAY_8
      CLR CLK
      LCALL DELAY_8
      DJNZ R7,LOOP6
      CLR DAT
      RET
RECEIVE:MOV R7,#8
        CLR CS
        SETB DAT
        LCALL DELAY_50        
LOOP7:SETB CLK
      LCALL DELAY_8
      MOV C,DAT
      MOV A,DATA_IN
      RLC A
      MOV DATA_IN,A          
      CLR CLK
      LCALL DELAY_8
      DJNZ R7,LOOP7
      CLR DAT
      RET
DELAY_50:MOV R6,#24
CY1:     DJNZ R6,CY1
         RET
DELAY_8:NOP
        NOP 
        NOP
        NOP 
        RET
END