51单片机的FIFO（先入先出）循环队列实现

// 文件：config.h

//////////////////////////////////////////////////////////

#ifndef __CONFIG_H
#define __CONFIG_H
//这一段无需改动
//This segment should not be modified
#ifndef TRUE
#define TRUE 1
#endif

#ifndef FALSE
#define FALSE 0
#endif

typedef unsigned char uint8; /* defined for unsigned 8-bits integer variable 无符号8位整型变量 */
typedef signed char int8; /* defined for signed 8-bits integer variable有符号8位整型变量 */
typedef unsigned short uint16; /* defined for unsigned 16-bits integer variable 无符号16位整型变量 */
typedef signed short int16; /* defined for signed 16-bits integer variable 有符号16位整型变量 */
typedef unsigned int uint32; /* defined for unsigned 32-bits integer variable 无符号32位整型变量 */
typedef signed int int32; /* defined for signed 32-bits integer variable 有符号32位整型变量 */
typedef float fp32; /* single precision floating point variable (32bits) 单精度浮点数（32位长度） */

＃i nclude "FIFOQUEUE.h"

#endif

//////////////////////////////////////////////////////////

// 文件：FIFOQUEUE.h

//////////////////////////////////////////////////////////

#ifndef _FIFOQUEUE_H
#define _FIFOQUEUE_H

#define ElemType uint8

#define QueueSize 20
#define QueueFull 0
#define QueueEmpty 1
#define QueueOperateOk 2

struct FifoQueue
{
uint16 front;
uint16 rear;
uint16 count;
ElemType dat[QueueSize];
};

//Queue Initalize
extern void QueueInit(struct FifoQueue *Queue);

// Queue In
extern uint8 QueueIn(struct FifoQueue *Queue,ElemType sdat);

// Queue Out
extern uint8 QueueOut(struct FifoQueue *Queue,ElemType *sdat);

#endif

//////////////////////////////////////////////////////////

// 文件：FIFOQUEUE.C

//////////////////////////////////////////////////////////

＃i nclude "config.h"

//Queue Init
void QueueInit(struct FifoQueue *Queue)
{
Queue->front = Queue->rear;
Queue->count = 0;
}

// Queue In
uint8 QueueIn(struct FifoQueue *Queue,ElemType sdat)
{
if((Queue->front == Queue->rear) && (Queue->count == QueueSize))
{ // full
return QueueFull;
}else
{ // in
Queue->dat[Queue->rear] = sdat;
Queue->rear = (Queue->rear + 1) % QueueSize;
Queue->count = Queue->count + 1;
return QueueOperateOk;
}
}

// Queue Out
uint8 QueueOut(struct FifoQueue *Queue,ElemType *sdat)
{
if((Queue->front == Queue->rear) && (Queue->count == 0))
{ // empty
return QueueEmpty;
}else
{ // out
*sdat = Queue->dat[Queue->front];
Queue->front = (Queue->front + 1) % QueueSize;
Queue->count = Queue->count - 1;
return QueueOperateOk;
}
}

//////////////////////////////////////////////////////////

// 文件：Main.C

//////////////////////////////////////////////////////////

＃i nclude
＃i nclude "config.h"

void main(void)
{
struct FifoQueue MyQueue;
ElemType sh;
uint8 i;

QueueInit(&MyQueue);
while(1)
{
for(i = 0;i < 30;i++)
{
if(QueueIn(&MyQueue,i) == QueueFull) break;
}
for(i = 0;i < 30;i++)
{
if(QueueOut(&MyQueue,&sh) == QueueEmpty) break;
}
}
while(1);
}