problem in serial communication between pc and 89c52

the code is

              ORG 0030h
                   MOV SP,#07H
          CLR P0.0
          CLR P0.1
          CLR P0.2
          CLR P0.4
          CLR P0.6
          CLR P0.7
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY

          SETB P0.4      ;PULSE FOR ALE
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY

          CLR P0.4
MAIN:MOV TMOD,#20H
     MOV TH1,#0FDH
         MOV SCON,#50H
         SETB TR1
HERE:JNB RI,HERE
     MOV A,SBUF
         MOV R7,A
         MOV R2,#30H
         MOV R1,#0AH
         MOV R0,#39H
BACK:CJNE A,00H,LOOP
     CLR C
         SUBB A,R2
         MOV R3,A
         SJMP END1
LOOP:DEC R0
     DJNZ R1,BACK
         MOV R0,#39H
         MOV R4,#06H
         MOV R5,#46H
         MOV R6,#37H
BACK1:CJNE A,05H,LOOP1
      CLR C
          SUBB A,R6
          MOV R3,A
          SJMP END1
LOOP1:DEC R5
      DJNZ R4,BACK1
          MOV R5,#46H
          CLR C
      MOV 08H,A
      SUBB A,R7
      JZ MAIN
      MOV A,08H
END1: NOP
MAIN1:CLR RI
          SETB TR1
HERE1:JNB RI,HERE1
      MOV A, SBUF
          MOV R7,A
          MOV R2,#30H
          MOV R1,#0AH
          MOV R0,#39H
BACK2:CJNE A,00H,LOOP2
      CLR C
          SUBB A,R2
          MOV R4,A
          MOV A,R3
          SWAP A
          ADD A,R4
          SJMP END2
LOOP2:DEC R0
      DJNZ R1,BACK2
          MOV R0,#39H
          MOV R4,#06H
          MOV R5,#46H
          MOV R6,#37H
BACK3:CJNE A,05H,LOOP3
      CLR C
          SUBB A,R6
          MOV R4,A
          MOV A,R3
          SWAP A
          ADD A,R4
          SJMP END2
LOOP3:DEC R5
      DJNZ R4,BACK3
          MOV R5,#46H
          CLR C
      MOV 08H,A
      SUBB A,R7
      JZ MAIN1
      MOV A,08H
END2: NOP
      MOV P2,A

;         A1:MOV R0,#0FFH        ;DELAY OF 15
;         A2:DJNZ R0,A2

          SETB P0.6                       ;PULSE FOR SOC
          A3:MOV R1,#0FH
          A4:DJNZ R1,A4

          CLR P0.6                       ;CLEAR SOC

;;        MOV R1,#69H
;   A5:DJNZ R1,A5
          LOOP4:JB P0.7,LOOP4           ; MONITOR EOC
 ;     ANL A,#80H
;         JZ LOOP4
;      ACALL DELAY
;         ACALL DELAY
     SETB P0.5        ;PULSE FOR OE
;        MOV R1,#0FH
;  A5:DJNZ R1,A5
                  ;     transmit to pc

      MOV TMOD,#20H
          MOV TH1,#0FDH
          MOV SCON,#50H
          SETB TR1
          MOV A,P1
;          CLR P0.5             ;LOW THE OE SIGNAL AFTER COMPLETE RECEPTION OF THE DATA
          MOV R3,A
          ANL A,#0F0H
          SWAP A
          MOV R2,#30H
          MOV R1,#0AH
          MOV R0,#09H
BACK4:CJNE A,00H,LOOP5
      CLR C
          ADD A,R2
          SJMP END3
LOOP5:DEC R0
      DJNZ R1,BACK4
          MOV R0,#09H
          MOV R4,#06
          MOV R5,#0FH
          MOV R6,#37H
BACK5:CJNE A,05H,LOOP6
      CLR C
          ADD A,R6
;         MOV P2,A      ;
          SJMP END3
LOOP6:DEC R5
      DJNZ R4,BACK5
          MOV R5,#0FH
 END3:NOP
      MOV SBUF,A
HERE2:JNB TI,HERE2
      CLR TI
          MOV A,R3
          ANL A,#0FH
          MOV R2,#30H
          MOV R1,#0AH
          MOV R0,#09H
BACK6:CJNE A,00H,LOOP7
     CLR C
          ADD A,R2
;         MOV P2,A
          SJMP END4
LOOP7:DEC R0
      DJNZ R1,BACK6
          MOV R0,#09H
          MOV R4,#06
          MOV R5,#0FH
          MOV R6,#37H
BACK7:CJNE A,05H,LOOP8
      CLR C
          ADD A,R6
          MOV R3,A
          SJMP END4
LOOP8:DEC R5
      DJNZ R4,BACK7
          MOV R5,#0FH
 END4:NOP
      MOV SBUF,A
HERE3:JNB TI,HERE3
      CLR TI
           LJMP MAIN

          ;DELAY SUBROUTINE
DELAY:MOV R0,#0FFH
 DELA:MOV R1,#0FFH
  DEL:DJNZ R1,DEL
      DJNZ R0,DELA
      RET

          END

the code is

              ORG 0030h
                   MOV SP,#07H
          CLR P0.0
          CLR P0.1
          CLR P0.2
          CLR P0.4
          CLR P0.6
          CLR P0.7
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY

          SETB P0.4      ;PULSE FOR ALE
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY
          ACALL DELAY

          CLR P0.4
MAIN:MOV TMOD,#20H
     MOV TH1,#0FDH
         MOV SCON,#50H
         SETB TR1
HERE:JNB RI,HERE
     MOV A,SBUF
         MOV R7,A
         MOV R2,#30H
         MOV R1,#0AH
         MOV R0,#39H
BACK:CJNE A,00H,LOOP
     CLR C
         SUBB A,R2
         MOV R3,A
         SJMP END1
LOOP:DEC R0
     DJNZ R1,BACK
         MOV R0,#39H
         MOV R4,#06H
         MOV R5,#46H
         MOV R6,#37H
BACK1:CJNE A,05H,LOOP1
      CLR C
          SUBB A,R6
          MOV R3,A
          SJMP END1
LOOP1:DEC R5
      DJNZ R4,BACK1
          MOV R5,#46H
          CLR C
      MOV 08H,A
      SUBB A,R7
      JZ MAIN
      MOV A,08H
END1: NOP
MAIN1:CLR RI
          SETB TR1
HERE1:JNB RI,HERE1
      MOV A, SBUF
          MOV R7,A
          MOV R2,#30H
          MOV R1,#0AH
          MOV R0,#39H
BACK2:CJNE A,00H,LOOP2
      CLR C
          SUBB A,R2
          MOV R4,A
          MOV A,R3
          SWAP A
          ADD A,R4
          SJMP END2
LOOP2:DEC R0
      DJNZ R1,BACK2
          MOV R0,#39H
          MOV R4,#06H
          MOV R5,#46H
          MOV R6,#37H
BACK3:CJNE A,05H,LOOP3
      CLR C
          SUBB A,R6
          MOV R4,A
          MOV A,R3
          SWAP A
          ADD A,R4
          SJMP END2
LOOP3:DEC R5
      DJNZ R4,BACK3
          MOV R5,#46H
          CLR C
      MOV 08H,A
      SUBB A,R7
      JZ MAIN1
      MOV A,08H
END2: NOP
      MOV P2,A

;         A1:MOV R0,#0FFH        ;DELAY OF 15
;         A2:DJNZ R0,A2

          SETB P0.6                       ;PULSE FOR SOC
          A3:MOV R1,#0FH
          A4:DJNZ R1,A4

          CLR P0.6                       ;CLEAR SOC

;;        MOV R1,#69H
;   A5:DJNZ R1,A5
          LOOP4:JB P0.7,LOOP4           ; MONITOR EOC
 ;     ANL A,#80H
;         JZ LOOP4
;      ACALL DELAY
;         ACALL DELAY
     SETB P0.5        ;PULSE FOR OE
;        MOV R1,#0FH
;  A5:DJNZ R1,A5
                  ;     transmit to pc

      MOV TMOD,#20H
          MOV TH1,#0FDH
          MOV SCON,#50H
          SETB TR1
          MOV A,P1
;          CLR P0.5             ;LOW THE OE SIGNAL AFTER COMPLETE RECEPTION OF THE DATA
          MOV R3,A
          ANL A,#0F0H
          SWAP A
          MOV R2,#30H
          MOV R1,#0AH
          MOV R0,#09H
BACK4:CJNE A,00H,LOOP5
      CLR C
          ADD A,R2
          SJMP END3
LOOP5:DEC R0
      DJNZ R1,BACK4
          MOV R0,#09H
          MOV R4,#06
          MOV R5,#0FH
          MOV R6,#37H
BACK5:CJNE A,05H,LOOP6
      CLR C
          ADD A,R6
;         MOV P2,A      ;
          SJMP END3
LOOP6:DEC R5
      DJNZ R4,BACK5
          MOV R5,#0FH
 END3:NOP
      MOV SBUF,A
HERE2:JNB TI,HERE2
      CLR TI
          MOV A,R3
          ANL A,#0FH
          MOV R2,#30H
          MOV R1,#0AH
          MOV R0,#09H
BACK6:CJNE A,00H,LOOP7
     CLR C
          ADD A,R2
;         MOV P2,A
          SJMP END4
LOOP7:DEC R0
      DJNZ R1,BACK6
          MOV R0,#09H
          MOV R4,#06
          MOV R5,#0FH
          MOV R6,#37H
BACK7:CJNE A,05H,LOOP8
      CLR C
          ADD A,R6
          MOV R3,A
          SJMP END4
LOOP8:DEC R5
      DJNZ R4,BACK7
          MOV R5,#0FH
 END4:NOP
      MOV SBUF,A
HERE3:JNB TI,HERE3
      CLR TI
           LJMP MAIN

          ;DELAY SUBROUTINE
DELAY:MOV R0,#0FFH
 DELA:MOV R1,#0FFH
  DEL:DJNZ R1,DEL
      DJNZ R0,DELA
      RET

          END

...is to go through that code and provide comments that describe what you think it is supposed to be doing!

Also strip-out all the redundant text.

This exercise alone may well take you to your mistake!

hi,

Why do you have given so much delay before serial communication settings?

Because if you type any character before settings, controller can not receive it.

Another thing is that clear RI flag & stop timer TR1 after receiving any character.

MAIN:MOV TMOD,#20H
     MOV TH1,#0FDH
     MOV SCON,#50H
     SETB TR1

HERE:JNB RI,HERE
     CLR RI
     CLR TR1
     MOV A,SBUF

thank you madam for your reply....actually i am doing my project and i am stuck in the programming part... i will make changes in the code and i will let you know the result..thank you again...

madam , when i am executing the above code (with tha above modifications), only "FF" is getting displayed in the hyperterminal when i press the characters from the keyboard.... i am not getting the where is the fault... will you provide me the code.. or the link where i can get some help on the code.. please...

madam

What about us poor males? What about us? Aren't you going to ask us? What about us? What?!?!?!

ya sure sir, but till now i am getting the satisfactory answer from madam only...thats y i mentioned madam... can you give me the solution for that..

And the first step to getting un-stuck is to properly comment the code that you have!

"i will make changes in the code"

There is no point in making random changes in the code if you aren't even sure what the current code does!

Above code is for receiving characters.

I think you are displaying the characters which you have typed from keypad.(if not then tell me what actually you want to do?)

for this first you take character from keypad, save it in one register, and then transmit it to hyper terminal.

And what about the link that I gave you in your other thread?

http://www.8052.com/faqs

Have you studied it yet?

Did you learn anything?

Have you checked all settings - baud rate, parity, etc - and on both the PC and the microcontroller?

You didn't say how you know that your connections are correct...

There is no point in making random changes in the code if you aren't even sure what the current code does!

"i will make changes in the code" .. i mean to say that i will include the some steps suggested by shital madam. i also don't change the code randomly.. because i need to complete my project as early as possible..!!!!

i also don't change the code randomly..

I have a feeling that is "shital madam" would tell you to, you would...

dear Tamir Michael
i am not getting why this is so.. (being an expert(hope so!))instead of giving steps to solve a problem you are replying something non sense...if you know the solution then give.. if you don know then..i think you can sit quite...

I don't understand why you refuse to really do what has been proposed to you (you are not alone, alas). Throughly read the user manual. Comment your code. All of it. Verify hardware settings on all parties involved. Test. Fly. Buy. Bye.

The steps have been given, and the first is to ensure that you fully understand the code that you have to start with!

An excellent way to ensure that you fully understand the code is to go through it carefully and comment what it is doing.

Once you fully understand the existing code, then - and only then - you can move on to modifying it...