hd7279driver.c

HD7279驱动程序

/*
* Copyright (c) 2006,中国传媒大学 广播电视数字化工程中心
* All rights reserved.
* 
* 文件名称：hd7279driver.c
* 作    者：脱立恒
* 摘    要：
* 创建日期：070808
* 当前版本：v0.1
* 修订日期：
* 
* 修订记录
* ---------------------------------------------------
* 修订人		|		版本		|		修订时间		|		修订内容		
*
*
*/
#include "hd7279driver.h"
//*** 变量及I/O口定义 ***
//unsigned char digit[5];
//unsigned char key_number;
//unsigned int tmr;
//unsigned long wait_cnter;

void write7279(unsigned char cmd, unsigned char dta)
{
  send_byte (cmd);
  send_byte (dta);
}
void send_byte( unsigned char out_byte)
{
  unsigned char i;
  cs=0;														//选中芯片7279
  long_delay();										//单片机延时
  for (i=0;i<8;i++)								//
   {
     if (out_byte&0x80)						//每次发1b，
       { 
         dat=1;
       }
     else
       {
         dat=0;
       }
     clk=1;
     short_delay();
     clk=0;
     short_delay();
     out_byte=out_byte*2;
   } 
  dat=0;
}
unsigned char receive_byte(void)
{
  unsigned char i, in_byte;
 dat=1;    // 设为输入状态
 long_delay();
 for (i=0;i<8;i++)
 {
  clk=1;
  short_delay();
  in_byte=in_byte*2;
  if (dat)
  {
   in_byte=in_byte|0x01;
  }
  clk=0;
  short_delay();
 }
 dat=0;
 return (in_byte);
}

void long_delay(void)
{
   unsigned char i;
   for (i=0;i<0x30;i++);
}
void short_delay(void)
{
   unsigned char i;
   for (i=0; i<8; i++);
}
void delay10ms(unsigned int time)
{
   unsigned int i;
   unsigned int j;
   for (i=0;i<time;i++)
    {
       for(j=0; j<0x3A3; j++)//
         {
           ;  
         }
     }
}
unsigned char read7279(unsigned char cmd)
{
	unsigned char keynumber;
	send_byte (cmd);
	keynumber = receive_byte();
	return (keynumber);
}
/*--------------------------------------------
调用方式：unsigned char HD7279_GetKey()函数﹫2001/05/12 
函数说明：私有函数，读键盘函数
--------------------------------------------*/
/*unsigned char HD7279_GetKey()
{ 
	unsigned char hdkey = NULLKEY; //键值初始化为NULLKEY＝0

	if(!key) 
		{ 
			hdkey = read7279 (CMD_READ); 
			switch ( hdkey ) 
			{	case RunKey: 
				case StopKey: 
				while (!key); 
				default: return(0xff); 
			} 
		} 
	return(0xff);
}*/