def_key.c

单片机与PS2鼠标接口设计 采用中断或查询多种方式

#include"config.h"
//ps2与单片机收发数据的常用函数，采用Atmega128  pd0时钟口  pd1数据口


//unsigned char InIndex=0,OutIndex=0;
//unsigned char KeyBuff[BUFF_SIZE]={0,0,0,0,0,0,0,0};

/*********************************************************/
//函数:Order()
//功能:单片机向键盘发送命令,关闭中断
//输入:命令
//输出:?
//描述:
/*********************************************************/
void Order(unsigned char orderByte)
{
    unsigned int i, j;
	
	EIMSK = 0x00;//关外部中断屏蔽寄存器
	DDRD|=0x03;
	
	PORTD &= 0xfe;					//Bring the Clock line low for at least 100 microseconds.
	delay_us(100);
	
	PORTD &= 0xfd;					//Bring the Data line low.
	delay_us(15);
	
	DDRD&=0xfe;	//Release the Clock line.

	while(PIND&0x01);					//Wait for the device to bring the Clock line low.

	for(i=0,j=0;i<8;i++)
	{
		if(orderByte&0x01)					//Set/reset the Data line to send the first data bit.
		{
			PORTD |= (1<<1);
			j++;
		}
		else
			PORTD &= ~(1<<1);
		
		orderByte >>=1;
		
		while(!(PIND&0x01));			//Wait for the device to bring Clock high.
		
		while(PIND&0x01);				//Wait for the device to bring Clock low.
	}
	
	if(!(j&0x01)) PORTD |= (1<<1);		//Send parity bit
	else PORTD &= ~(1<<1);
	
	while(!(PIND&0x01));				//Wait for the device to bring Clock high.
		
	while(PIND&0x01);					//Wait for the device to bring Clock low.

	PORTD |= (1<<1);					//Send stop bit
	
	while(!(PIND&0x01));				//Wait for the device to bring Clock high.
		
	while(PIND&0x01);					//Wait for the device to bring Clock low.

	DDRD &=0xfd ;		               //Release the Data line.
	
	while(PIND&0x02);					//Wait for the device to bring Data low.
	
	while(PIND&0x01);					//Wait for the device to bring Clock low.
	
	while((PIND&0x03)!=0x03);			//Wait for the device to release Data and Clock.
	
	EIMSK = 0x01;//开外部中断屏蔽寄存器
	
}

/*************************
//函数:ps2_init()
//功能:ps2键盘上电初始化与单片机的交互识别
//输入：
//输出：
*************************/
void ps2_init(void)
{    
     unsigned int i;
 	 EIMSK = 0x00;//关外部中断屏蔽寄存器

	 for(i=0;i<1000;i++)
	 	;//延时稳定
	 /* 初始化变量 */
	 DDRC  |= 0x80;
	 PORTC |= 0x80; //关键盘电源
	 for(i=0;i<1000;i++)
	 delay_us(10);
  
	DDRD  |= 0x07;
	
	PORTC &= 0x7f;//开键盘
	PORTD |= 0x03;
	EIMSK = 0x01;//开外部中断屏蔽寄存器
	delay_us(50);
	state_flag=1;
	while(!KeyBoardConnectFlag);//等待键盘自检成功

	Order(COMMAND_RESET); //复位键盘

	delay_us(5);

	Order(COMMAND_SETSTATUS);//设置状态灯CapsLock,NumLock,ScrollLock

	Order(DISALL); //关闭所有灯

	Order(COMMAND_SETSTATUS); 

	Order(NUMLOCK_EN); //开NumLock灯

	Order(COMMAND_SETRATE); //设置速率延时

	Order(0x20); //500ms/30

	Order(COMMAND_ENABLE); //使能键盘

	Order(COMMAND_SETRATE); //设置速率延时

	Order(0x20); //
	delay_us(200); //延时
	state_flag=0;
 }

#pragma interrupt_handler int0_isr:2
void int0_isr(void)
{
 //external interupt on INT0
 static unsigned char BitCount=11,KeyData=0;
	if(BitCount<11 && BitCount>2)
	{   
	    DDRD&=0xfd;
		KeyData>>=1;
		if(KeyBoardSda)
			KeyData|=0x80;
	}
	if(--BitCount==0)
	{
		BitCount=11;
		//KeyBuff[InIndex]=KeyData;
		
		//if(KeyData == CODE_POST)
       // KeyBoardConnectFlag = 1;//键盘上电初始化成功的标志
	   KeyBoardDecode(KeyData);
		
		//if(++InIndex==BUFF_SIZE)
			//InIndex=0;
		KeyData=0;
	}
	
}


void delay_1us(void)
{
 asm("nop");
}
void delay_us(unsigned int n)
{
 unsigned int i;
 for(i=n;i>0;i--)
 delay_1us();
}