8051 Code Examples

Turbo51 - Free Pascal compiler for 8051

Here are some test projects suitable for any 8051 microcontroller to show how to use Turbo51. They can also be used to quickly see generated code.

	Example 1 This is a '8051 hello world' example.
	Example2 This is a simple example. It shows basic features of Turbo51.
	Example 3 This example is part of some real 8051 project. It shows how to use Turbo51 and its features.
	Example 4 This example demonstrates sets and inline procedures/functions.

8051 calculator example in Turbo51

This is an example of a simple calculator - it should work on any 8051 microcontroller, just adjust oscillator frequency and baud rate formula. Below you can see compiled code.

Program Calculator;

Const
 Osc = 22118400;
 BaudRateTimerValue = Byte (- Osc div 12 div 32 div 19200);

Var SerialPort: Text;
    Num1, Num2: LongInt;

Procedure WriteToSerialPort; Assembler;
Asm
  CLR   TI
  MOV   SBUF, A
@WaitLoop:
  JNB   TI, @WaitLoop
end;

Function ReadFromSerialPort: Char;
Var ByteResult: Byte absolute Result;
begin
  While not RI do;
  RI := False;
  ByteResult := SBUF;

{ Echo character }

  Asm
    MOV    A, Result
    LCALL  WriteToSerialPort
  end;
end;


Procedure Init;
begin
  TL1  := BaudRateTimerValue;
  TH1  := BaudRateTimerValue;
  TMOD := %00100001;    { Timer1: no GATE, 8 bit timer, autoreload }
  SCON := %01010000;    { Serial Mode 1, Enable Reception }
  TI   := True;         { Indicate TX ready }
  TR1  := True;         { Enable timer 1 }
end;

{$DefaultFile On }

begin
  Init;
  Assign (CurrentIO, ReadFromSerialPort, WriteToSerialPort);

  Writeln ('Turbo51 IO file demo - integer calculator');
  Repeat
    Write   ('Enter first number: ');
    Readln  (Num1);
    Write   ('Enter second number: ');
    Readln  (Num2);
    Writeln (Num1, ' + ', Num2, ' = ', Num1 + Num2);
    Writeln (Num1, ' - ', Num2, ' = ', Num1 - Num2);
    Writeln (Num1, ' * ', Num2, ' = ', Num1 * Num2);
  until False;
end.

Compiled code looks like this:

; Turbo51 version 0.1.3.1, Copyright 2000 - 2008 Igor Funa

$REGISTERBANK (0)

_CODE         SEGMENT  CODE
_CONST        SEGMENT  CODE
_DATA         SEGMENT  DATA

              EXTRN    DATA  (CurrentIO)
              EXTRN    IDATA (StackStart)

              EXTRN    CODE  (sysWriteStr_CODE)
              EXTRN    CODE  (sysWriteLine)
              EXTRN    CODE  (sysReadLongInt)
              EXTRN    CODE  (sysStore_Long0_To_IDATA)
              EXTRN    CODE  (sysReadLine)
              EXTRN    CODE  (sysLoad_Long0_From_IDATA)
              EXTRN    CODE  (sysPushLongIntBCD)
              EXTRN    CODE  (sysWriteDecimalPushedBytes)
              EXTRN    CODE  (sysLoad_Long1_From_IDATA)
              EXTRN    CODE  (sysLongAddition)
              EXTRN    CODE  (sysLongSubtraction)
              EXTRN    CODE  (sysLongMultiplication)

; Program Calculator;
; 
; Const

RSEG _CONST

;  Osc = 22118400;
;  BaudRateTimerValue = Byte (- Osc div 12 div 32 div 19200);
; 
; Var SerialPort: Text;
;     Num1, Num2: LongInt;

RSEG _DATA

Num1:                           DS       4
Num2:                           DS       4

; 
; Procedure WriteToSerialPort; Assembler;


RSEG _CODE

USING 0

WriteToSerialPort:
; Asm
;   CLR   TI
              CLR       SCON.1

;   MOV   SBUF, A
              MOV       SBUF, A

; @WaitLoop:
L_0111:
;   JNB   TI, @WaitLoop
              JNB       SCON.1, L_0111

; end;
              RET

; 
; Function ReadFromSerialPort: Char;

RSEG _DATA

ReadFromSerialPort_Result:      DS       1

; Var ByteResult: Byte absolute Result;
ByteResult                      EQU      ReadFromSerialPort_Result


RSEG _CODE

ReadFromSerialPort:
; begin
;   While not RI do;
L_0115:
              JNB       SCON.0, L_0115

;   RI := False;
              CLR       SCON.0

;   ByteResult := SBUF;
              MOV       ReadFromSerialPort_Result, SBUF

; 
; { Echo character }
; 
;   Asm
;     MOV    A, Result
              MOV       A, ReadFromSerialPort_Result

;     LCALL  WriteToSerialPort
              LCALL     WriteToSerialPort

;   end;
; end;
              MOV       A, ReadFromSerialPort_Result
              RET

; 
; 
; Procedure Init;

Init:
; begin
;   TL1  := BaudRateTimerValue;
              MOV       TL1, #$FD

;   TH1  := BaudRateTimerValue;
              MOV       TH1, #$FD

;   TMOD := %00100001;    { Timer1: no GATE, 8 bit timer, autoreload }
              MOV       TMOD, #$21

;   SCON := %01010000;    { Serial Mode 1, Enable Reception }
              MOV       SCON, #$50

;   TI   := True;         { Indicate TX ready }
              SETB      SCON.1

;   TR1  := True;         { Enable timer 1 }
              SETB      TCON.6

; end;
              RET

RSEG _CONST

C_0435:                         DB        41, 'Turbo51 IO file demo - integer calculator'
C_045F:                         DB        20, 'Enter first number: '
C_0474:                         DB        21, 'Enter second number: '
C_048A:                         DB        3, ' + '
C_048E:                         DB        3, ' = '
C_0492:                         DB        3, ' - '
C_0496:                         DB        3, ' * '


CSEG AT 0

Files:
; 
; {$DefaultFile On }
; 
; begin
              MOV       SP, #StackStart-1

;   Init;
              LCALL     Init

;   Assign (CurrentIO, ReadFromSerialPort, WriteToSerialPort);
              MOV       CurrentIO, #LOW  (WriteToSerialPort)
              MOV       CurrentIO+1, #HIGH (WriteToSerialPort)
              MOV       CurrentIO+2, #LOW  (ReadFromSerialPort)
              MOV       CurrentIO+3, #HIGH (ReadFromSerialPort)

; 
;   Writeln ('Turbo51 IO file demo - integer calculator');
              MOV       DPTR, #C_0435
              MOV       R6, #0
              LCALL     sysWriteStr_CODE
              LCALL     sysWriteLine

;   Repeat
L_001D:
;     Write   ('Enter first number: ');
              MOV       DPTR, #C_045F
              MOV       R6, #0
              LCALL     sysWriteStr_CODE

;     Readln  (Num1);
              LCALL     sysReadLongInt
              MOV       R0, #Num1
              LCALL     sysStore_Long0_To_IDATA
              LCALL     sysReadLine

;     Write   ('Enter second number: ');
              MOV       DPTR, #C_0474
              MOV       R6, #0
              LCALL     sysWriteStr_CODE

;     Readln  (Num2);
              LCALL     sysReadLongInt
              MOV       R0, #Num2
              LCALL     sysStore_Long0_To_IDATA
              LCALL     sysReadLine

;     Writeln (Num1, ' + ', Num2, ' = ', Num1 + Num2);
              MOV       R0, #Num1
              LCALL     sysLoad_Long0_From_IDATA
              LCALL     sysPushLongIntBCD
              MOV       R6, #0
              LCALL     sysWriteDecimalPushedBytes
              MOV       DPTR, #C_048A
              MOV       R6, #0
              LCALL     sysWriteStr_CODE
              MOV       R0, #Num2
              LCALL     sysLoad_Long0_From_IDATA
              LCALL     sysPushLongIntBCD
              MOV       R6, #0
              LCALL     sysWriteDecimalPushedBytes
              MOV       DPTR, #C_048E
              MOV       R6, #0
              LCALL     sysWriteStr_CODE
              MOV       R0, #Num1
              LCALL     sysLoad_Long0_From_IDATA
              MOV       R0, #Num2
              LCALL     sysLoad_Long1_From_IDATA
              LCALL     sysLongAddition
              LCALL     sysPushLongIntBCD
              MOV       R6, #0
              LCALL     sysWriteDecimalPushedBytes
              LCALL     sysWriteLine

;     Writeln (Num1, ' - ', Num2, ' = ', Num1 - Num2);
              MOV       R0, #Num1
              LCALL     sysLoad_Long0_From_IDATA
              LCALL     sysPushLongIntBCD
              MOV       R6, #0
              LCALL     sysWriteDecimalPushedBytes
              MOV       DPTR, #C_0492
              MOV       R6, #0
              LCALL     sysWriteStr_CODE
              MOV       R0, #Num2
              LCALL     sysLoad_Long0_From_IDATA
              LCALL     sysPushLongIntBCD
              MOV       R6, #0
              LCALL     sysWriteDecimalPushedBytes
              MOV       DPTR, #C_048E
              MOV       R6, #0
              LCALL     sysWriteStr_CODE
              MOV       R0, #Num1
              LCALL     sysLoad_Long0_From_IDATA
              MOV       R0, #Num2
              LCALL     sysLoad_Long1_From_IDATA
              CLR       C
              LCALL     sysLongSubtraction
              LCALL     sysPushLongIntBCD
              MOV       R6, #0
              LCALL     sysWriteDecimalPushedBytes
              LCALL     sysWriteLine

;     Writeln (Num1, ' * ', Num2, ' = ', Num1 * Num2);
              MOV       R0, #Num1
              LCALL     sysLoad_Long0_From_IDATA
              LCALL     sysPushLongIntBCD
              MOV       R6, #0
              LCALL     sysWriteDecimalPushedBytes
              MOV       DPTR, #C_0496
              MOV       R6, #0
              LCALL     sysWriteStr_CODE
              MOV       R0, #Num2
              LCALL     sysLoad_Long0_From_IDATA
              LCALL     sysPushLongIntBCD
              MOV       R6, #0
              LCALL     sysWriteDecimalPushedBytes
              MOV       DPTR, #C_048E
              MOV       R6, #0
              LCALL     sysWriteStr_CODE
              MOV       R0, #Num1
              LCALL     sysLoad_Long0_From_IDATA
              MOV       R0, #Num2
              LCALL     sysLoad_Long1_From_IDATA
              LCALL     sysLongMultiplication
              LCALL     sysPushLongIntBCD
              MOV       R6, #0
              LCALL     sysWriteDecimalPushedBytes
              LCALL     sysWriteLine

;   until False;
              LJMP      L_001D

; end.

              END