Assemby level code to C code conversion help

[Nishanth]

Someone please help me convert this assembly code to c code. 

 

 

ORG 00H                // origin

MOV DPTR,#LUT          // moves the address of LUT to DPTR

MOV P1,#00000000B      // sets P1 as output port

MOV P0,#00000000B      // sets P0 as output port

CLR P3.0               // sets P3.0 as output for sending trigger

SETB P3.1              // sets P3.1 as input for receiving echo

MOV TMOD,#00100000B    // sets timer1 as mode 2 auto reload timer

MAIN: MOV TL1,#207D    // loads the initial value to start counting from

      MOV TH1,#207D    // loads the reload value

      MOV A,#00000000B // clears accumulator

      SETB P3.0        // starts the trigger pulse

      ACALL DELAY1     // gives 10uS width for the trigger pulse

      CLR P3.0         // ends the trigger pulse

HERE: JNB P3.1,HERE    // loops here until echo is received

BACK: SETB TR1         // starts the timer1

HERE1: JNB TF1,HERE1   // loops here until timer overflows (ie;48 count)

      CLR TR1          // stops the timer

      CLR TF1          // clears timer flag 1

      INC A            // increments A for every timer1 overflow

      JB P3.1,BACK     // jumps to BACK if echo is still available

      MOV R4,A         // saves the value of A to R4

      ACALL DLOOP      // calls the display loop

      SJMP MAIN        // jumps to MAIN loop

 

DELAY1: MOV R6,#2D     // 10uS delay

LABEL1: DJNZ R6,LABEL1

        RET     

 

DLOOP: MOV R5,#100D    // loads R5 with 100D

BACK1: MOV A,R4        // loads the value in R4 to A

       MOV B,#100D     // loads B with 100D

       DIV AB          // isolates the first digit

       SETB P1.0       // activates LED display unit D1

       ACALL DISPLAY   // calls DISPLAY subroutine

       MOV P0,A        // moves digit drive pattern for 1st digit to P0

       ACALL DELAY     // 1mS delay

       ACALL DELAY

       MOV A,B         // moves the remainder of 1st division to A

       MOV B,#10D      // loads B with 10D

       DIV AB          // isolates the second digit

       CLR P1.0        // deactivates LED display unit D1

       SETB P1.1       // activates LED display unit D2

       ACALL DISPLAY

       MOV P0,A        // moves digit drive pattern for 2nd digit to P0

       ACALL DELAY

       ACALL DELAY

       MOV A,B         // moves the remainder of 2nd division to A

       CLR P1.1        // deactivates LED display unit D2

       SETB P1.2       // activates LED display unit D3

       ACALL DISPLAY

       MOV P0,A        // moves the digit drive pattern for 3rd digit to P0

       ACALL DELAY

       ACALL DELAY

       CLR P1.2       // deactivates LED display unit D3

       DJNZ R5,BACK1  // repeats the display loop 100 times

       RET

 

DELAY: MOV R7,#250D        // 1mS delay

LABEL2: DJNZ R7,LABEL2

        RET

 

DISPLAY: MOVC A,@A+DPTR   // gets the digit drive pattern for the content in A

         CPL A            // complements the digit drive pattern (see Note 1)

         RET

LUT: DB 3FH               // look up table (LUT) starts here

     DB 06H

     DB 5BH

     DB 4FH

     DB 66H

     DB 6DH

     DB 7DH

     DB 07H

     DB 7FH

     DB 6FH

END

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