/*
	max7219 驅動程序 基于51單片機

	zhaoliang_0801@dl.cn
	07-3-27

*/

#include <reg51.h> 
/*****************************
宏定義聲明
*****************************/
//common part 
#define  HIGH     1
#define  LOW      0
#define  TRUE     1
#define  FALSE    0
#define  ZERO     0 
#define  MSB      0x80
#define  LSB      0x01
//max7219 part
#define  DECODE_MODE   0x09 
#define  INTENSITY     0x0A 
#define  SCAN_LIMIT    0x0B 
#define  SHUT_DOWN     0x0C 
#define  DISPLAY_TEST  0x0F 

/*************************************************************************
管腳定義：
不同的電路板上，改變這里的定義，
*************************************************************************/
sbit LOAD = P3^5; //MAX7219    Load-Data Input:    	rising edge  	pin 12 
sbit DIN  = P3^6; 	//MAX7219    Serial-Data Input:   	rising edge  	pin 1
sbit CLK  = P3^7; 	//MAX7219   Serial-Clock Input:  	maximum 10MHz  	pin 13

/***********************************************************
函數聲明
***********************************************************/
void Write_Max7219_byte(unsigned char temp);
void Write_Max7219(unsigned char address,unsigned char dat);
void Init_Max7219(void);

/***************
測試程序，
顯示1~8
***************/
void main(void)
{
	unsigned char i; 
	Init_Max7219();  
	while(TRUE)
	{  
		for(i=1; i<9; i++) 
		{
			Write_Max7219(i,i);
		}
	} 
}
/******************************************
發送一個字節的子程序：
上升沿發送數據，
MSB first
******************************************/
void Write_Max7219_byte(unsigned char temp)
{
	unsigned char i;
	for (i=0; i<8; i++)     
	{ 
		CLK = LOW;
		DIN = (bit)(temp&MSB);      
		temp <<=1;  
		CLK = HIGH;
	}
}
/**********************************************************
向寄存器中寫入一個數據
先寫地址，后寫數據
load 上升沿鎖存數據
**********************************************************/
void Write_Max7219(unsigned char address,unsigned char dat)
{ 
	LOAD = LOW;
	Write_Max7219_byte(address); 
	Write_Max7219_byte(dat);
	LOAD = HIGH;                 
}
/**********************
初始化max7219 子函數
設置工作寄存器
需要查看芯片手冊
**********************/
void Init_Max7219(void)      
{ 
	Write_Max7219(SHUT_DOWN, 	0x01);   //Normal Operation XXXXXXX1 Shutdown Mode   XXXXXXXX0
	Write_Max7219(DISPLAY_TEST, 0x00);   //Normal Operation XXXXXXX0 Display Test Mode XXXXXXXX1
	Write_Max7219(DECODE_MODE, 	0xff);   //Decode Mode Select D7~D0 1 B decode 0 No decode 
	Write_Max7219(SCAN_LIMIT, 	0x07);   //SCAN LIMIT 0~7 0xX0~0xX7
	Write_Max7219(INTENSITY, 	0x04);   //Set Intensity   0xX0~0xXf
}