VI XỬ LÝ 8051 chap8 c programming

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Chapter 8

C Programming for 8051

The 8051 Microcontroller

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TS. Lê Chí Thông

[email protected]

sites.google.com/site/chithong

Ho Chi Minh City University of Technology

Outline

• Structure of a C program

• Using Keil

• Declaration of the types of memory

• Variable types

• Keywords in Keil C51

• Functions

• Operations – Statements

• Time delay

• I/O programming

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References

• Cx51 Compiler User Guide (pdf)

http://www.neuromorphs.net\nm\raw-attachment\wiki\2010\usb10\C51.PDF

• Matthew Kramer, Writing C Code for the 8051 (pdf)

http://www.kel.ftn.uns.ac.rs/predmeti/3/mpe/razno/writing_c_code_8051.pdf

• M. Mazidi, J. Mazidi, and R. McKinlay, The 8051 Microcontroller

and Embedded Systems Using Assembly and C (2nd ed.)

• Chung-Ping Young, 8051 Programming in C (pdf)

• Ibrahim Kamal, C programming for 8051 using KEIL IDE,

http://www.ikalogic.com/part-2-c-programming-for-8051-using￾keil-ide/

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Blinky Program

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(Schematic)

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Blinky Program

//Documentatons

/**************************

Blinky program

Date: 05-Apr-2012

Version: 1.0

***************************/

//Preprocessor Statements

#include <reg51.h>

#define ON 1

#define OFF 0

// Global declarations

sbit LED1=P1^0;

// Subprograms

/* Delay in milliseconds for a 11.0592 MHz crystal */

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void Delayms (unsigned int ms) {

unsigned int i;

while (ms) {

i = 115;

while (i> 0) i--;

ms--;

}

}

// Main Program

main (void) {

while (1) {

LED1 = ON; // Turn on LED1

Delayms (500); // Delay 500 ms

LED1 = OFF; // Turn off LED1

Delayms (500); // Delay 500 ms

}

source }

From the C program

to the machine language

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Source: http://www.ikalogic.com/part-2-c-programming-for-8051-using-keil-ide/

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C Programming for the 8051

• C programming is less time consuming, but has

larger hex file size

• The reasons for writing programs in C

– It is easier and less time consuming to write in C than

Assembly

– C is easier to modify and update

– You can use code available in function libraries

– C code is portable to other microcontroller with little

of no modification

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Source: Chung-Ping Young, 8051 Programming in C

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Documentations

Preprocessor Statements

Global Declarations

Subprograms (User defined functions)

Main Program (Main function)

Structure of a C program

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//Documentatons

//Name of the program, programmer,

//and other details

//Preprocessor Statements

#include <stdio.h> //header files

#include <reg51.h>

#define TRUE 1 //symbolic constants

#define FALSE 0

//Global Declarations

unsigned char x,y;

int z;

long n=0;

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//Subprograms

Void function1 (int x) {

//Statements

}

//Main function

void main(void)

{

int sum = 0; //Local Declarations

int x;

float y;

//Statements

}

Structure of a C program

Keil Product Downloads

http://www.keil.com/download/product/

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