ds1302.c

这是一个UCOS的AVR移植程序

#include "includes.h"

/****************************************************************************/
/*************************DS1302******************************************/

/* 字节写 */   //把一个字节写进1302
void writeChar(unsigned char data)
{
	unsigned char i;

	for (i = 0; i < 8; i++)
	{
		CLR_TIMER_SCLK;
		asm volatile ("nop	\n\t" ::);
		
		CLR_TIMER_IO;
		if (data & 0x01)
		{
			SET_TIMER_IO;//如果输入的第i位为1，则IO口置为1，否则为0
		}
		asm volatile ("nop	\n\t" ::);
		
		SET_TIMER_SCLK;
		asm volatile ("nop	\n\t" ::);
		data >>= 1;
	}
}

/* 字节读 */
unsigned char readChar(void)
{
	unsigned char i;
	unsigned char retVal = 0;
	
	DDRB &= ~(1<<DDB4);//PB4设为输入上拉 读IO时，PB4设为输入
	PORTB |= (1<<PORTB4);
	
	for (i = 0; i < 8; i++)
	{
		CLR_TIMER_SCLK;
		asm volatile ("nop	\n\t" ::);
		
		retVal >>= 1;
		if (PINB & 0x10)						// (PINB & (1<<PORTB4))
		{
			retVal |= 0x80;//PB4为0则retval的第i位为0，为1则第i位为1
		}
		asm volatile ("nop	\n\t" ::);
		
		SET_TIMER_SCLK;
		asm volatile ("nop	\n\t" ::);
	}
	
	DDRB |= (1<<DDB4);//PB4输出为1  IO口输出1
	PORTB |= (1<<PORTB4);
	
	return retVal;
}

// 寄存器设置  感觉是用来校准时间的，也用来设置时间
void setChipReg(unsigned char addr,unsigned char data)
{
	CLR_TIMER_SCLK;
	asm volatile ("nop	\n\t" ::);	
	SET_TIMER_REST;
	asm volatile ("nop	\n\t" ::);

	writeChar(addr);//地址中有控制命令
	writeChar(data);
	
	CLR_TIMER_SCLK;
	asm volatile ("nop	\n\t" ::);
	CLR_TIMER_REST;
	asm volatile ("nop	\n\t" ::);
}

/* 寄存器读取 */
unsigned char getChipReg(unsigned char addr)
{
	unsigned char retVal;
	
	CLR_TIMER_SCLK;
	asm volatile ("nop	\n\t" ::);	
	SET_TIMER_REST;
	asm volatile ("nop	\n\t" ::);
	
	writeChar(addr);
	retVal = readChar();

	CLR_TIMER_SCLK;
	asm volatile ("nop	\n\t" ::);
	CLR_TIMER_REST;
	asm volatile ("nop	\n\t" ::);
	
	return retVal;
}


// 写保护控制
void chipWriteProtect(unsigned char condition)
{
	if (!condition)//condition为0将写保护关闭，为1打开
	{
		setChipReg(0x8E,0x00);//将写保护关闭
	}
	else
	{
		setChipReg(0x8E,0x80);//将写保护打开
	}
}


// 启动计时
void chipClockStart(unsigned char condition)
{
	unsigned char tmpChar;
	unsigned char tmpPB = PORTB & 0x18;//取PB3,PB4，为了操作完能恢复
	setChipReg(0x8E,0x00);//将写保护关了

	tmpChar = getChipReg(0x81);//读sec寄存器的值，用来判断时钟是否打开
	if (tmpChar & 0x80)//如果sec寄存器的第7位为1，说明时钟关闭
	{
		if (condition)//condition为1，打开时钟
		{
			setChipReg(0x80,(tmpChar&0x7F));//打开时钟
			setChipReg(0x90,CHARGE_ON_2_3);	// Just For This Routine
		}
	}
	else//时钟本来就打开
	{
		if (!condition)//condition为0，关掉时钟
		{
			setChipReg(0x80,(tmpChar|0x80));//关掉时钟
		}
	}
	setChipReg(0x8E,0x80);//写保护打开
	tmpChar = PORTB & 0xE7;//这两行主要是还原PORTB口的值
	PORTB = tmpChar | tmpPB;
}


// 充电寄存器设置
void setChargeReg(unsigned char chargeMode)
{
	setChipReg(0x8E,0x00);		// 可写
	setChipReg(0x90,chargeMode);
	setChipReg(0x8E,0x80);//不可写，即写保护打开
}

	
/* burstMode 写 */
void burstModeTimeWrite(unsigned char *pClock)
{
	unsigned char i;
	unsigned char tmpPB = PORTB & 0x38;//取PB3,PB4,PB5，在操作完可恢复
	
	DDRB |= (1<<DDB5);//PB5输出0，即处于复位状态
	PORTB &= ~(1<<PORTB5);
	
	setChipReg(0x8E,0x00);//将写保护关了，可写
	
	CLR_TIMER_SCLK;
	asm volatile ("nop	\n\t" ::);
	SET_TIMER_REST;
	asm volatile ("nop	\n\t" ::);
	
	writeChar(0xBE);//设置为BURSTMODE，这种模式连续读/写8个时钟寄存器
	
	for(i = 8;i > 0;i--)//不需要写入地址，固定是对那8个地址的操作，只需写入数据
	{
 		writeChar(*pClock);
 		pClock++;
	}
	
	CLR_TIMER_SCLK;
	asm volatile ("nop	\n\t" ::);
	CLR_TIMER_REST;
	asm volatile ("nop	\n\t" ::);
	
	setChipReg(0x8E,0x80);//写保护打开，不可写
	
	i = PORTB & 0xC7;//还原PORTB的值
	PORTB = tmpPB | i;
	
	DDRB &= ~(1<<DDB5);//PB5输入上拉，不处于复位状态
	PORTB |= (1<<PORTB5);
}

/* burstMode 读 */
void burstModeTimeRead(unsigned char *pClock)
{
	unsigned char i;
	unsigned char tmpPB = PORTB & 0x38;
	
	DDRB |= (1<<DDB5);
	PORTB &= ~(1<<PORTB5);
	
	setChipReg(0x8E,0x00);	
	
	CLR_TIMER_SCLK;
	asm volatile ("nop	\n\t" ::);
	SET_TIMER_REST;
	asm volatile ("nop	\n\t" ::);
	
	writeChar(0xBF);
	
	for(i = 8;i > 0;i--)
	{
 		*pClock = readChar();
 		pClock++;
	}
	
	CLR_TIMER_SCLK;
	asm volatile ("nop	\n\t" ::);
	CLR_TIMER_REST;
	asm volatile ("nop	\n\t" ::);
	
	setChipReg(0x8E,0x80);
	
	i = PORTB & 0xC7;
	PORTB = tmpPB | i;
	
	DDRB &= ~(1<<DDB5);
	PORTB |= (1<<PORTB5);
}