6.2. Structure of a C

The following program shows the basic structure of a program in C with the Keil C51 software.

 /************************************************* *********
 Example structure of a program in C with the Keil C51
 and microcontrollers 8051.

 Program to flash all the bits of Port 0
 with time.

 Author: Rafael Aranda
 Date: 20-10-2009
 Version: 1.0
************************************************** ********/

# Include <reg52.h> / / Include the generic domains of 8052

DelayMs void (unsigned int ms) / / function prototype declaration

			/ / Global variable declaration


/ / Main Program
//------------------------------------------------ ----------
void main (void) {
        
	/ / Force initial preparation
   	P0 = 0, / / Set all bits to 0 P0
	
	/ / Body of the program in an infinite loop
	while (1) {
	
		P0 = 0x0FF / / Set all bits to 1 P0
		DelayMs (200) / / Delay 200 mS
		P0 = 0x00, / / Set all bits to 0 P0
		DelayMs (200) / / Delay 200 mS
		}
}


/ / Delay function
//------------------------------------------------ ----------
DelayMs void (unsigned int ms) { 
 
	/ / Delay in milliseconds for a 11.0592 MHz crystal 
    unsigned int i; 
    while (ms) {
        i = 115; 
		while (i> 0) i -;
        ms -;
    }
}