【Keil5 C51】AT89C52 water lamp experiment (call C51 library function _crol

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Introduction to the _crol_ function

Cx51 User’s Guide

Summary

#include

unsigned char _crol_ (

unsigned char c, /* character to rotate left */

unsigned char b); /* bit positions to rotate */

Description

The _crol_ routine rotates the bit pattern for the character c left b bits. This routine is implemented as an intrinsic function (starting from bit 1 in the c variable and moving left b bits at a time, for example, when b = 1, the string of numbers will move like this: 1111110–>11111101)

Return Value

The crol routine returns the rotated value of c.

Example

#include

void test_crol (void) {

char a;

char b;

a = 0xA5;

b = _crol_(a,3); /* b now is 0x2D */

}

Flowing light code

Using AT89C52 chip, crystal oscillator is 11.0592MHz

#include

#define uint unsigned int

#define uchar unsigned char

void delay(uint time);

void main()

{

uint led = 0xfe; //11111110

while(1){

P1 = led; //11111110 Turn on the first light of P1 port first

delay(500); //delay 0.5s

led = _crol_(led,1); //Call the _crol_ function to shift the led variable left from the first one 11111110-->11111101

//Return to led, now led = 11111101

}

void delay(uint time) //delay = 1 ms 0.001s

{

uint x;

uint the;

uint z;

for(z = time; z > 0; z--){

for(x = 1; x > 0; x--){

for(y = 115; y > 0; y--){}

}

Proteus simulation diagram

insert image description here

Keywords：Keil5 C51 AT89C52 Reference address：【Keil5 C51】AT89C52 water lamp experiment (call C51 library function _crol_)

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