8279问题求高手指点迷津

只看该作者 · 2012-3-13 18:05

在单片机和8279调试的时候发现不能稳定的工作，下面是我写的程序，请高手看看那有问题
D8279 EQU 8000H
  C8279 EQU 8001H
   ORG 0000H
LJMP START
   ORG 000BH
LJMP TIMER0INT
   ORG 0013H
LJMP KEYINT

   ORG 0040H
START:  MOV SP,#90H
  SETB P1.5
  MOV 73H,#00
  LCALL SERIALINIT
  LCALL TIMER0INIT
  LCALL C8279INIT
  SETB TR0
  SETB EA
  SETB EX1
  CLR IT1
   ;MAIN PROGRAM BEGIN
MAIN:
  MOV A,73H
  CLR C
  SUBB A,#5
  JC LOOP
  MOV DPTR,#C8279
  MOVX A,@DPTR
  MOV SBUF,A
  LCALL DELAY
  SETB P1.5
  MOV 73H,#00
LOOP:  JNB TI,MAIN
  CLR TI
  LJMP MAIN

   ;8279(keyboard) intrrupt sub-program
KEYINT:
  PUSH ACC
  PUSH PSW
  PUSH DPL
  PUSH DPH
  SETB RS0
  CLR RS1
  CLR P1.5
  MOV DPTR,#D8279
  MOVX A,@DPTR
  MOV SBUF,A
  POP DPH
   POP DPL
   POP PSW
   POP ACC
   RETI
TIMER0INT:
  PUSH ACC
  PUSH PSW
  PUSH DPL
  PUSH DPH
  MOV TH0,#2CH
  MOV TL0,#13H
  INC 73H
  POP DPH
  POP DPL
  POP PSW
  POP ACC
   RETI

SERIALINIT:    ;INIT SERIAL
  MOV SCON,#50H
  MOV TL1,#0F9H
  MOV TH1,#0F9H
  SETB TR1
  RET
TIMER0INIT:    ;INIT TIMER0
  MOV TMOD,#21H
  MOV TH0,#2CH
  MOV TL0,#13H
  SETB ET0
  RET
C8279INIT:    ;INIT 8279
  MOV DPTR,#C8279
   MOV A,#01H  ;KEY MODE
   MOVX @DPTR,A
  LCALL DELAY
   MOV A,#34H  ;CLK=100KHZ,2MHZ/20=100K
   MOVX @DPTR,A
  LCALL DELAY
   MOV A,#0C3H       ;CLEAR FIFO RAM
   MOVX @DPTR,A
  LCALL DELAY
WAIT:    MOVX A,@DPTR
  JB ACC.7,WAIT
  RET
DELAY:
   MOV R2,#250
      DJNZ R2,$
      RET

  END