key_ht_isr.c

此为按键部分的,读取按键值是否有按键判断部分函数

/*
*********************************************************************************************************
*                                    Embedded Systems Building Blocks

* Filename   : KEY_HT_ISR.C
* Programmer : LuHaijun
* 
* This program can not use alone,it must copy to main file
/*
*********************************************************************************************************
*                                              INCLUDE FILES
*********************************************************************************************************
*/

#include "INCLUDES.H"


//sbit ZLG7289_pinINT=P1^6;          //键盘中断请求信号，低电屏（负边沿）有效

/*
*********************************************************************************************************
*                                            GLOBAL VARIABLES
*********************************************************************************************************
*/

extern   INT8U     KeyBuf[KEY_BUF_SIZE];     /* Keyboard buffer                                         */
extern   INT8U     KeyBufInIx;               /* Index into key buf where next scan code will be inserted*/
extern   INT8U     KeyBufOutIx;              /* Index into key buf where next scan code will be removed */
extern   INT8U     KeyDownTmr;               /* Counts how long key has been pressed                    */
extern   INT8U     KeyNRead;                 /* Number of keys read from the keyboard                   */
extern   INT8U     KeyScanState;             /* Current state of key scanning function                  */
extern   INT8U     KeyRptStartDlyCtr;        //累加延时时间
extern   INT8U     KeyRptDlyCtr;
extern   INT8U    ccode;
/*
*********************************************************************************************************
*                                       LOCAL FUNCTION PROTOTYPES
*********************************************************************************************************
*/
#if OS_CRITICAL_METHOD == 3                                /* Allocate storage for CPU status register */
   extern OS_CPU_SR  cpu_sr;
#endif
void  KeyScanISR ()                           //按键扫描函数
{
         switch (KeyScanState) {
            case KEY_STATE_UP:                             /* See if need to look for a key pressed    */
                if(ZLG7289_pinINT==0){                     //判断按键是否按下
                     KeyScanState = KEY_STATE_DEBOUNCE;    /* Next call we will have debounced the key */
                }
                break;

            case KEY_STATE_DEBOUNCE:                       /* Key pressed, get scan code and buffer    */
                if  (ZLG7289_pinINT==0) {             //看按键是否仍在压下状态
                    ccode =ZLG7289_Key();             //读出按键值
                    if (KeyNRead < KEY_BUF_SIZE) {    //如果按键缓冲区没满             
                       KeyNRead++;                              
                       KeyBuf[KeyBufInIx++] = ccode;            
                       if (KeyBufInIx >= KEY_BUF_SIZE) {  //如果指针到头则返回      
                           KeyBufInIx = 0;
                       }
                    }                                     /* Input scan code in buffer                */
                    KeyRptStartDlyCtr = KEY_RPT_START_DLY;      //启动累加延时
                    KeyScanState      = KEY_STATE_RPT_START_DLY;
                } else {
                    //KeySelRow(KEY_ALL_ROWS);              /* Select all row                           */
                    KeyScanState      = KEY_STATE_UP;     //返回到按键检测状态
                }
                break;

            case KEY_STATE_RPT_START_DLY:
                if  (ZLG7289_pinINT==0) {                     //如果按键仍被按下
                    if (KeyRptStartDlyCtr > 0) {              //延时时间递减
                        KeyRptStartDlyCtr--;              /* Yes, decrement counter to start of rpt   */
                        if (KeyRptStartDlyCtr == 0) {     //如果延时时间减到0
                            ccode =ZLG7289_Key();             //读出按键值              
                            if (KeyNRead < KEY_BUF_SIZE) {              
                                KeyNRead++;                              
                                KeyBuf[KeyBufInIx++] = ccode;            
                                if (KeyBufInIx >= KEY_BUF_SIZE) {        
                                    KeyBufInIx = 0;
                                }
                            }                      /* Input scan code in buffer                */
                            KeyRptDlyCtr = KEY_RPT_DLY;     //置处理每个按键的间隔时间
                            KeyScanState = KEY_STATE_RPT_DLY; //进入连续处理状态
                        }
                    }
                } else {
                    KeyScanState = KEY_STATE_DEBOUNCE;    //跳回判断按键是否还被压下状态
                }
                break;

            case KEY_STATE_RPT_DLY:
                 if  (ZLG7289_pinINT==0) {                 //判断按键是否仍然被按下
                     if (KeyRptDlyCtr > 0) {               //按键延时处理
                         KeyRptDlyCtr--;                   /* Yes, dec. wait time to next key repeat   */
                         if (KeyRptDlyCtr == 0) {          /* See if it's time to repeat key           */
                             ccode =ZLG7289_Key();             //读出按键值
                             if (KeyNRead < KEY_BUF_SIZE) {    //判断缓冲区是否满             
                                KeyNRead++;                              
                                KeyBuf[KeyBufInIx++] = ccode;            
                                if (KeyBufInIx >= KEY_BUF_SIZE) {        
                                    KeyBufInIx = 0;
                                }
                            }                            /* Input scan code in buffer                */
                            KeyRptDlyCtr = KEY_RPT_DLY;     //重新付值按键延时时间
                        }
                    }
                } else {
                    KeyScanState = KEY_STATE_DEBOUNCE;    //跳回判断按键是否还被压下状态
                }
                break;
        }
}