keyscan.c

六路智能抢答器

//========================================================
//	语法格式：	unsigned int KeyScan(void)
//	实现功能：	获得键盘值并返回
//	参数：		无
//	返回值：	键盘值
//========================================================
# include "SPCE061A.h"

unsigned int KeyScan1(void)
{
	unsigned int uiData;
	unsigned int uiTemp;
	uiData = *P_IOA_Data;				//读取IOA端口输入
	uiData = uiData&0x0003;				//仅取低八位有效值
	if(uiData!=0)						//非零则表示有键按下
	{
		delay();						//延时消抖
		uiTemp = *P_IOA_Data;
		uiTemp = uiTemp&0x0003;			//仅取低八位有效值
		if(uiData != uiTemp)
			uiData = 0;					//两次读数不相等，则置返回值为0
	}
	return uiData;						//返回键值	
}

unsigned int KeyScan2(void)
{
	unsigned int uiData;
	unsigned int uiTemp;
	uiData = *P_IOA_Data;				//读取IOA端口输入
	uiData = uiData&0x00fc;				//仅取高八位有效值
	if(uiData!=0)						//非零则表示有键按下
	{
		delay();						//延时消抖
		uiTemp = *P_IOA_Data;
		uiTemp = uiTemp&0x00fc;			//仅取高八位有效值
		if(uiData != uiTemp)
			uiData = 0;					//两次读数不相等，则置返回值为0
	}
	return uiData;						//返回键值	
}



void delay(void)
{
	unsigned int uiCount;
	for(uiCount = 0;uiCount < 50; uiCount++)
	{
		*P_Watchdog_Clear = 0x0001;    //清看门狗操作
	}
}