ORG 0000H
LJMP START



ORG 1000H



START:
MOV IE,#10000001b
MOV TMOD,#00010001B
MOV P3,#0FFH
MOV R3,#0EH


MOV TL1,#000H
MOV TH1,#000H

SERIAL:
    MOV TMOD, #20H ; Timer 1 in mode 2 (8-bit auto-reload)
    MOV TH1, #0FDH ; Timer 1 high byte set for 2400 baud rate
    MOV TL1, #0FDH ; Timer 1 low byte (auto-reload value)
    SETB TR1       ; Start Timer 1
    MOV SCON, #50H ; Mode 1 (8-bit UART), REN enabled (receive enabled)
    RET

RANGECHECK:
    MOV A, SBUF        
    SUBB A, #30H        
    JNC  BELOWRANGE    
    CJNE A, #09H, OUTRANGE 
    
    SJMP INSIDERANGE      

BELOWRANGE:
    CJNE A, #01H, OUTRANGE 
    SJMP INSIDERANGE       

OUTRANGE:
    MOV A, #'E' 
    ACALL SERIALTRANSMIT
    MOV A, #'R' 
    ACALL SERIALTRANSMIT
    MOV A, #'R' 
    ACALL SERIALTRANSMIT
    MOV A, #'O' 
    ACALL SERIALTRANSMIT
    MOV A, #'R' 
    ACALL SERIALTRANSMIT
    RET

SERIALTRANSMIT:
    JNB TI, $ 
    CLR TI    
    MOV SBUF, A 
    RET

INSIDERANGE:
    RET

NOTAC5:
SETB TR1

SETB P2.0
ACALL C5_DELAY
CLR P2.0
ACALL C5_DELAY

JNB TF1,NOTAC5
CLR TR1
CLR TF1
DJNZ R3,NOTAC5

MOV R3,#0EH

MOV TL1,#000H
MOV TH1,#000H


NOTAD5:
SETB TR1

SETB P2.0
ACALL D5_DELAY
CLR P2.0
ACALL D5_DELAY

JNB TF1,NOTAD5
CLR TR1
CLR TF1
DJNZ R3,NOTAD5

MOV R3,#0EH

MOV TL1,#000H
MOV TH1,#000H


NOTAE5:
SETB TR1

SETB P2.0
ACALL E5_DELAY
CLR P2.0
ACALL E5_DELAY

JNB TF1,NOTAE5
CLR TR1
CLR TF1
DJNZ R3,NOTAE5

MOV R3,#0EH

MOV TL1,#000H
MOV TH1,#000H


NOTAF5:
SETB TR1

SETB P2.0
ACALL F5_DELAY
CLR P2.0
ACALL F5_DELAY

JNB TF1,NOTAF5
CLR TR1
CLR TF1
DJNZ R3,NOTAF5

MOV R3,#0EH

MOV TL1,#000H
MOV TH1,#000H


NOTAG5:
SETB TR1

SETB P2.0
ACALL G5_DELAY
CLR P2.0
ACALL G5_DELAY

JNB TF1,NOTAG5
CLR TR1
CLR TF1
DJNZ R3,NOTAG5

MOV R3,#0EH

MOV TL1,#000H
MOV TH1,#000H


NOTAA5:
SETB TR1

SETB P2.0
ACALL A5_DELAY
CLR P2.0
ACALL A5_DELAY

JNB TF1,NOTAA5
CLR TR1
CLR TF1
DJNZ R3,NOTAA5

MOV R3,#0EH

MOV TL1,#000H
MOV TH1,#000H


NOTAB5:
SETB TR1

SETB P2.0
ACALL B5_DELAY
CLR P2.0
ACALL B5_DELAY

JNB TF1,NOTAB5
CLR TR1
CLR TF1
DJNZ R3,NOTAB5

MOV R3,#0EH

MOV TL1,#000H
MOV TH1,#000H


NOTAC6:
SETB TR1

SETB P2.0
ACALL C6_DELAY
CLR P2.0
ACALL C6_DELAY

JNB TF1,NOTAC6
CLR TR1
CLR TF1
DJNZ R3,NOTAC6



LJMP START

C5_DELAY:

MOV TH0,#0FCH
MOV TL0,#04AH

SETB TR0
JNB TF0,$
CLR TR0
CLR TF0
RET


D5_DELAY:

MOV TH0,#0FCH
MOV TL0,#0ADH

SETB TR0
JNB TF0,$
CLR TR0
CLR TF0
RET

E5_DELAY:

MOV TH0,#0FDH
MOV TL0,#009H

SETB TR0
JNB TF0,$
CLR TR0
CLR TF0
RET

F5_DELAY:

MOV TH0,#0FDH
MOV TL0,#034H

SETB TR0
JNB TF0,$
CLR TR0
CLR TF0
RET

G5_DELAY:
MOV TH0,#0FDH
MOV TL0,#082H

SETB TR0
JNB TF0,$
CLR TR0
CLR TF0
RET

A5_DELAY:
;MOV TMOD, #01H
MOV TH0,#0FDH
MOV TL0,#0C7H

SETB TR0
JNB TF0,$
CLR TR0
CLR TF0
RET

B5_DELAY:

MOV TH0,#0FEH
MOV TL0,#005H

SETB TR0
JNB TF0,$
CLR TR0
CLR TF0
RET

C6_DELAY:

MOV TH0,#0FEH
MOV TL0,#022H

SETB TR0
JNB TF0,$
CLR TR0
CLR TF0
RET



END