第1个回答 推荐于2018-03-22
;51 单片机的汇编语言程序:
ORG 0000H
JMP START
ORG 0023H
JB TI, S0_END
CLR RI
MOV A, 34H
MOV 34H, SBUF
MOV R0, #33H
S0_L:
XCH A, @R0
DEC R0
CJNE R0, #2FH, S0_L
SETB F0
S0_END:
RETI
START:
MOV SCON, #50H
MOV TMOD, #20H
MOV TH1, #0FDH
MOV TL1, #0FDH
SETB TR1
MOV IE, #90H
M_LOOP:
JNB F0, M_LOOP
CLR F0
MOV R1, #30H
CJNE @R1, #'h', M_LOOP
INC R1
CJNE @R1, #'e', M_LOOP
INC R1
CJNE @R1, #'l', M_LOOP
INC R1
CJNE @R1, #'l', M_LOOP
INC R1
CJNE @R1, #'o', M_LOOP
MOV SBUF, #'O'
JNB TI, $
CLR TI
MOV SBUF, #'K'
JNB TI, $
CLR TI
JMP M_LOOP
END本回答被提问者和网友采纳
第2个回答 2014-03-14
FLAG BIT 00H
ORG 0000H
LJMP MAIN
ORG 0023H
LJMP UART
ORG 0030H
MAIN:
MOV TMOD,#20H
MOV TH1,#0FDH
MOV TL1,#0FDH
MOV SCON,#50H
SETB TR1
SETB ES
SETB EA
MOV R0,#30H
MOV R2,#0
CLR FLAG
LOOP:
JNB FLAG LOOP
MOV A,30H
CJNE A,#'h',RETRY
MOV A,31H
CJNE A,#"e',RETRY
MOV A,32H
CJNE A,#'l',RETRY
MOV A,33H
CJNE A,#'l',RETRY
MOV A,34H
CJNE A,#'o',RETRY
CLR TI
MOV SBUF,#'O'
JNB TI,$
CLR TI
MOV SBUF,#'K'
JNB TI,$
CLR TI
RETRY:
MOV R0,#30H
MOV R2,#0
CLR FLAG
LJMP LOOP
UART:
JB RI,RECIVE
RETI
RECIVE:
CLR RI
MOV A,SBUF
MOV @R0,A
INC R0
INC R2
CJNE R2,#5,UEND
SETB FLAG
UEND:
RETI
END