max7219.c

基于ARM的按键测试开发.很实用也很普遍.

#include <max7219.h>
#include <INTRINS.H>

extern unsigned char code ascii[];

void WriteToMax7219 (unsigned char Cmd ,unsigned char Data)
{
   unsigned char tLoop  = 0;
   unsigned int   tMask = 0x0001;
   unsigned int   tWord = 0;


   tWord = Cmd;
   tWord = (tWord << 8) + Data;
   CLK0  = 0;
   CS0   = 0;
   for(tLoop=0,tMask=0x8000; tLoop<16 ;tLoop++)
   {
   
      	DIN0=tWord&tMask;

   		_nop_();   
   		_nop_();        //rising edge
   		CLK0=1;
   		if(tLoop==15)   //Take CS high (while CLK is still high after clocking in                    
   		CS0=1;
      	CLK0=0;
   		DIN0=0;
   
   		tMask=tMask>>1; 
  }
  CS0=1;
}


void InitialMax7219(void)
{
  unsigned char i; 
  CS0=1;
  CLK0=0;
//Enter display test mode 
//WriteToMax7219(0x0F,0x01);
//Exit display test mode
  WriteToMax7219(0x0F,0x00);

// Exit shutdown mode -->normal mode
  WriteToMax7219(0x0C,0x01);
 
//Set globalk intensity to full-scale 
  WriteToMax7219(0x0A ,0x06);
// WriteToMax7219(0x02 ,0x08);

//Decode mode enabled 0-7 BCD decode
  WriteToMax7219(0x09,0xFF) ;

//Display Digit 0-7 only
  WriteToMax7219(0x0B,0x07) ;

//reset all 8 leds to blank
  for(i=2;i<9;i++)
  {
  	 WriteToMax7219(i,ascii[8]);
  }
  WriteToMax7219(0x01,0x0E);

}