key.c

利用单片机扩展8155芯片 4*4键盘扫描

#include <REG51.h>    /* Device specific head file*/
#include <intrins.h>
#include <absacc.h>   /* Absolute memory access   */
#include <math.h>
#define uchar unsigned char
#define uint  unsigned int
#define ulong unsigned long

void keyscan(void);
//void Delay(void);
void display(unsigned char i);
void Initialize(void);


/**************************看门狗*************************/
void Dog()
{
    uchar xdata *plcd;
    plcd = 0xA000;
    *plcd = 0x00;
}

void keyscan()
{
	unsigned char n;
	unsigned char m;
	XBYTE[0x8012]=0xef;
	m=XBYTE[0x8013];
	m&=0x0f;
	if(m!=0x0f)
	{
		Delay(630);
		XBYTE[0x8012]=0xef;
		m=XBYTE[0x8013];
		m&=0x0f;
		if(m!=0x0f)
		{
			m=XBYTE[0x8013];
			m&=0x0f;
			switch(m)
			{
				case(0x0e):/*display(0)sendbuf(0)*/n=3;break;
				case(0x0d):/*display(1)sendbuf(1)*/n=2;break;
				case(0x0b):/*display(2)sendbuf(2)*/n=1;break;
				case(0x07):/*display(3)sendbuf(3)*/n=0;break;
			}
		}
	}
	/*P1=0xfd;
	n=P1;
	n&=0xf0;
	if(n!=0xf0)
	{
		Delay(430);
		P1=0xfd;
		n=P1;
		n&=0xf0;
		if(n!=0xf0)
		{
			switch(n)
			{
				case(0xe0):display(4);break;
				case(0xd0):display(5);break;
				case(0xb0):display(6);break;
				case(0x70):display(7);break;
			}
		}
	}
	P1=0xfb;
	n=P1;
	n&=0xf0;
	if(n!=0xf0)
	{
		Delay(430);
		P1=0xfb;
		n=P1;
		n&=0xf0;
		if(n!=0xf0)
		{
			switch(n)
			{
				case(0xe0):display(8);break;
				case(0xd0):display(9);break;
				case(0xb0):display(10);break;
				case(0x70):display(11);break;
			}
		}
	}
	P1=0xf7;
	n=P1;
	n&=0xf0;
	if(n!=0xf0)
	{
		Delay(430);
		P1=0xf7;
		n=P1;
		n&=0xf0;
		if(n!=0xf0)
		{
			switch(n)
			{
				case(0xe0):display(12);break;
				case(0xd0):display(13);break;
				case(0xb0):display(14);break;
				case(0x70):display(15);break;
			}
		}
	}*/
}

void display(unsigned char i)
{
	unsigned char table[]=
	{
		0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90,0x88,0x83,0xC6,0xA1,0x86,0x8E
	};
	P2=0xfe;
	P0=table[i];
}

void main()
{
	while(1)
	{
		keyscan();
	}
}