rs232.asm

51单片机基础篇 对于有一定基础的人看看 包含书中所以的源代码

       ORG 0H
       JMP RESET
       ORG 23H
       JMP RECEIVE
RESET
       MOV TMOD,#00100000B
       MOV TH1,#32           ;2400 baud
       MOV IE,#10010000B
       MOV IP,#00010000B
       SETB TR1
       MOV SCON,#01010000B   ;8,n,1 UART
       MOV A,#1
WAIT
       CPL P3.7
       RL A
       MOV P1,A
       CALL DELAY
       JMP WAIT
DELAY:
       MOV R7,#10
       DJNZ R7,$
       RET
TABLE: INC A
       MOVC A,@A+PC
       RET
;7_SEG_TABLE            
       DB      00111111B,00000110B,01011011B
       DB      01001111B,01100110B,01101101B
       DB      01111101B,00100111B,01111111B
       DB      01101111B,01110111B,01111100B
       DB      00111001B,01011110B,01111001B
       DB      01110001B
RECEIVE:
       CLR RI
       PUSH ACC
       MOV A,SBUF
       MOV SBUF,A
       CLR C
       SUBB A,#30H
       CALL TABLE
       MOV P3,A
       POP ACC
       CLR TI
       RETI
       END