一个写的比较牛逼的51定时器中断

来源：https://wenku.baidu.com/view/de230f2bcc7931b765ce1591.html

主要思想是将定时器的任务放到链表里面，通过注册，初始化定时器任务，通过遍历完成事件查询。简化了程序代码。

#ifndef _TIMER_CONFIG_H_

#define _TIMER_CONFIG_H_
#include "const.h"
#include "oscfrequencydef.h"
#ifndef OSC_FREQUENCY
#error undefined OSC_FREQUENCY
#endif


//#warning must be used in AT89C52 or later version because of "idata"
#warning **********************************************************************************
#warning !! make sure MAX_TIMER_EVENT_NUM and TI
MER0_BASE_INTERVAL has appropriate value!!
#warning **********************************************************************************
#define MAX_TIMER_EVENT_NUM 5 //可设置不同定时事件的最大个数(至少为2)
#define TIMER0_BASE_INTERVAL 20 //单位：毫秒
typedef void (*TIMERPROC)(BYTE nID);
void InitTimer0();
BOOL SetTimerCallback(TIMERPROC lpTimerFunc); //必须在SetTimer0之前调用
BOOL SetTimer0(BYTE nID, WORD wInterval); //通过nID(nID>0)来区分
//BOOL KillTimer0(BYTE nID);
/////////////////////////////////////////////////


//以下为内部使用


typedef struct tagTIMERINFO{
BYTE nID; //定时器ID
WORD wInterval; //此定时器的设定间隔时间
WORD wElapse; //剩余的时间
}TIMERINFO;


static BOOL AddTail(const TIMERINFO* pTimerInfo);
static BOOL Remove(BYTE nID);
static BYTE FindID(BYTE nID);


#endif






#ifndef _CONST_H_
#define _CONST_H_
#include


#define TRUE 1
#define FALSE 0


typedef unsigned char BYTE;
typedef unsigned int WORD;
typedef unsigned long DWORD;
typedef float FLOAT;
typedef char CHAR;
typedef unsigned char UCHAR;
typedef int INT;
typedef unsigned int UINT;
typedef unsigned long ULONG;
typedef UINT WPARAM;
typedef ULONG LPARAM;
typedef ULONG LRESULT;
typedef void VOID;
typedef const CONST;
typedef void *PVOID;
typedef bit BOOL;


#define MAKEWORD(lo, hi) ((WORD)(((BYTE)(lo)) | ((WORD)((BYTE)(hi))) << 8))
#define MAKEDWORD(lo, hi) ((DWORD)(((WORD)(lo)) | ((DWORD)((WORD)(hi))) << 16))
#define LOWORD(l) ((WORD)(l))
#define HIWORD(l) ((WORD)(((DWORD)(l) >> 16) & 0xFFFF))
#define LOBYTE(w) ((BYTE)(w))
#define HIBYTE(w) ((BYTE)(((WORD)(w) >> 8) & 0xFF))
#define MAX(a, b) (((a) > (b)) ? (a) : (b))
#define MIN(a, b) (((a) < (b)) ? (a) : (b))
#define SET_STATE_FLAG(state, mask) ((state) |= (mask))
#define RESET_STATE_FLAG(state, mask) ((state) &= ~(mask))
#define TEST_STATE_FLAG(state, mask) ((state) & (mask))
#define TEST_BIT(b, offset) (1 & ((b) >> (offset)))
#define SET_BIT(b, offset) ((b) |= (1 << (offset)))
#define RESET_BIT(b, offset) ((b) &= (~(1 << (offset))))
//将BCD码变为十进制，如将0x23变为23
//注意:高四位和低四位均不能大于9
#define BCD_TO_DECIMAL(bcd) ((BYTE)((((BYTE)(bcd)) >> 4) * 10 + (((BYTE)(bcd)) & 0x0f)))
#define DECIMAL_TO_BCD(decimal) ((BYTE)(((((BYTE)(decimal)) / 10) << 4) | ((BYTE)(decimal)) % 10))
#define NOP() _nop_()
#define BYTE_ROTATE_LEFT(b, n) _crol_(b, n)
#define BYTE_ROTATE_RIGHT(b, n) _cror_(b, n)
#define WORD_ROTATE_LEFT(w, n) _irol_(w, n)
#define WORD_ROTATE_RIGHT(w, n) _iror_(w, n)
#define DWORD_ROTATE_LEFT(dw, n) _lrol_(dw, n)
#define DWORD_ROTATE_RIGHT(dw, n) _lror_(dw, n)
#define ENABLE_ALL_INTERRUPTS() (EA = 1)
#define DISABLE_ALL_INTERRUPTS() (EA = 0)
#endif












#include "timerconfig.h"
#include "chiptypedef.h"
#include
#include


code const WORD TIMER0_INIT_VALUE = UINT_MAX - ((WORD)((float)OSC_FREQUENCY * 1.0f / 12 * 1000)) * TIMER0_BASE_INTERVAL;
idata TIMERINFO TimerInfoArray[MAX_TIMER_EVENT_NUM] = {0};
TIMERPROC g_pfnTimerFunc = NULL;
BYTE g_nTimerInfoNum = 0; //当前队列的元素个数


void InitTimer0(){
TMOD |= T0_M0_; //定时器0,工作方式1
TH0 = HIBYTE(TIMER0_INIT_VALUE);
TL0 = LOBYTE(TIMER0_INIT_VALUE);
TR0 = 0; //停止定时器0
ET0 = 0; //关定时器0中断
EA = 1;
}


BOOL SetTimerCallback(TIMERPROC lpTimerFunc){
if(lpTimerFunc == NULL)
return FALSE;
g_pfnTimerFunc = lpTimerFunc;
return TRUE;
}


BOOL SetTimer0(BYTE nID, WORD wInterval){
TIMERINFO ti;
if(g_pfnTimerFunc == NULL || nID == 0 || wInterval == 0)
return FALSE;
if(wInterval % TIMER0_BASE_INTERVAL != 0) //定时间隔必须是TIMER0_BASE_INTERVAL的整数倍
return FALSE;
if(FindID(nID) != MAX_TIMER_EVENT_NUM) //若已经有相同的ID存在
return FALSE;
ti.nID = nID;
ti.wInterval = wInterval;
ti.wElapse = wInterval;
if(!AddTail(&ti))
return FALSE;
TR0 = 1; //启动定时器0
ET0 = 1; //开定时器0中断
return TRUE;
}


static BYTE FindID(BYTE nID){
BYTE i = 0;
for(i = 0; i < MAX_TIMER_EVENT_NUM; i++){
if(TimerInfoArray[i].nID == nID)
return i;
}
return MAX_TIMER_EVENT_NUM;
}


static BOOL AddTail(const TIMERINFO* pTimerInfo){
if(g_nTimerInfoNum == MAX_TIMER_EVENT_NUM || pTimerInfo == NULL)
return FALSE;

memcpy(&TimerInfoArray[g_nTimerInfoNum], pTimerInfo, sizeof(TIMERINFO));
g_nTimerInfoNum++;
return TRUE;
}


void Timer0ISR() interrupt TF0_VECTOR
{
BYTE i = 0;
TF0 = 0;
TH0 = HIBYTE(TIMER0_INIT_VALUE);
TL0 = LOBYTE(TIMER0_INIT_VALUE);
for(i = 0; i < g_nTimerInfoNum; i++){
TimerInfoArray[i].wElapse -= TIMER0_BASE_INTERVAL;
if(TimerInfoArray[i].wElapse == 0){
(*g_pfnTimerFunc)(TimerInfoArray[i].nID);
TimerInfoArray[i].wElapse = TimerInfoArray[i].wInterval;
}
}
}