近期由于项目需求，被指定使用一款实时时钟芯片RX8900SA，经查询后发现网络资源很少，便在此记录一下使用笔记，方便查询使用，附代码。后期发现爱普生的RX8025t芯片手册内容相近，资源多且有中文手册，可对比查看。
芯片采用I2C通讯方式，具体时序查看芯片应用手册，常用的引脚如下：
SDA/SCL：用于I2C通讯；
/INT：用于闹钟报警，正常状态时是高电平，中断发生后，引脚电平由 高3V->低；
Vbat：连接电池；
1.芯片寄存器一共有15个，00~06用来设置和读取实时时间，数据格式为BCD码，需要注意的是03WEEK寄存器数据格式是不一样的，每个位对应周几（不许进行BCD码转换）；
2.08~0A是用来对定时闹钟的时间配置，闹钟配置有两种方式具体操作在下面；
3.0D~0F是控制寄存器，用来设定中断方式、定时方式、中断标志位等；
1.设备地址为64，想要写入相应的寄存器，需要先发设备地址，然后寄存器地址，然后数值，比如WriteByteAdd(Rx8900sa_ADD,15,0x08); //使能alarm中断信号AIE；
2.读取相应的寄存器，需要先发设备地址，然后相应的寄存器，比如typGetAlarmTime.AF=ReadByteAdd(Rx8900sa_ADD,14);//读取中断标志寄存器，AF在第3位,0开始计数。
开启闹钟定时报警功能（即到点儿/INT引脚就由高变低），主要分两步：
1.设置定时时间，闹钟最小定时时间为分钟，设置不到秒，最大设置时间为日，若想要更长时间的定时，添加应用代码即可，分钟/小时时间设置向08/09寄存器写入数值即可，数值80h~FFh中及代表忽略（即每一分钟或者每小时）；这里比较特殊的是day和week的定时，时间设置在0A寄存器，但需要使用0D寄存器的WADA位来控制，0代表周时间报警，1代表日时间报警，0A寄存器数据格式最高位为1的话表示每一天。
2.设置2个寄存器（0D,0F）,清除1个中断标志位；0D Extension Register寄存器中第6位WADA用来控制按照day设定的时间报警，还是用week设定的时间报警，0F Control Register寄存器的第3位AIE是用来使能闹钟定时中断，因此在初始化的时候需要对该为写1；1个中断标志位是0E Flag Register寄存器的第3位AF，在初始化的时候需要进行清0，当定时时间到，中断发生，该标志位置1，/INT引脚电平由3V->0V，清零该标志位后便可进行下一次定时报警，不清除不再会触发定时报警。
其中包括一些延时函数，用于自己的开发环境中重新定义一下即可，这里的OS.h主要用来设定延时函数
代码片.
/*************************************************
File name: //Rx8900sa.c/h
Author： //Davidysw
Version: //V1.0
Description: //用于驱动Rx8900sa实时时钟芯片
// 读取秒、分、时、周、日、月、年
// 设定闹钟分、时、日
Others: // 具体操作查看应用手册
Log: //
*************************************************/
#include <msp430.h>
#include "OS.h"
#include "Rx8900sa.h"
TIME typNowTime,typSetTime;
ALARM typSetAlarmTime,typGetAlarmTime;
/*
*@ Description: 转换为BCD码
*@ param 1 ：例如传进来的是51，转换成0x51,实时时钟存储的是BCD码
*@ param 2
*@ return
*/
uint8_t hex_2bcd(uint8_t s)
{
uint8_t temp;
uint8_t t;
s %= 100;
temp = s / 10;
if(!temp) //如果为0
{
t = s ;
}
else
{
t = temp * 6 + s; //10进制转16进制，超过10的数*6
}
return t;
}
/*
*@ Description: 读取实时时间->typNowTime
*@ param 1
*@ param 2
*@ return
*/
void Rx8900sa_ReadNowTime(void)
{
uint8_t buff_rd[7];
uint8_t i;
for(i = 0; i < 7;i ++)
{
buff_rd[i] = ReadByteAdd(Rx8900sa_ADD,i);
}
typNowTime.second = ((buff_rd[0] >> 4) & 0x07) * 10 + (buff_rd[0] & 0x0f);
typNowTime.minute = ((buff_rd[1] >> 4) & 0x07) * 10 + (buff_rd[1] & 0x0f);
typNowTime.hour = ((buff_rd[2] >> 4) & 0x03) * 10 + (buff_rd[2] & 0x0f);
//typNowTime.week = ((buff_rd[3] >> 4) & 0x07) * 10 + (buff_rd[3] & 0x0f);
typNowTime.day = ((buff_rd[4] >> 4) & 0x03) * 10 + (buff_rd[4] & 0x0f);
typNowTime.month = ((buff_rd[5] >> 4) & 0x01) * 10 + (buff_rd[5] & 0x0f);
typNowTime.year = ((buff_rd[6] >> 4) & 0x0f) * 10 + (buff_rd[6] & 0x0f);
switch(buff_rd[3])
{
case 0x02:
{
typNowTime.week=1;
}break;
case 0x04:
{
typNowTime.week=2;
}break;
case 0x08:
{
typNowTime.week=3;
}break;
case 0x10:
{
typNowTime.week=4;
}break;
case 0x20:
{
typNowTime.week=5;
}break;
case 0x40:
{
typNowTime.week=6;
}break;
case 0x01:
{
typNowTime.week=7;
}break;
default:
{
typNowTime.week=0;
}break;
}
}
/*
*@ Description: 设置实时时间->typSetTime
*@ param 1 Rx8900sa_SetNowTime(31,0,6,1,18,11,19);
*@ param 2
*@ return
*/
uint16_t Rx8900sa_SetNowTime(uint8_t second,uint8_t minute,uint8_t hour,uint8_t week,uint8_t day,uint8_t month,uint8_t year)
{
uint8_t i;
uint8_t buff_wr[7];
static TIME set_time_old;
typSetTime.second = second;
typSetTime.minute = minute;
typSetTime.hour = hour;
//typSetTime.week = week;
typSetTime.day = day;
typSetTime.month = month;
typSetTime.year = year;
switch(week)
{
case 1:
{
typSetTime.week=0x02;
}break;
case 2:
{
typSetTime.week=0x04;
}break;
case 3:
{
typSetTime.week=0x08;
}break;
case 4:
{
typSetTime.week=0x10;
}break;
case 5:
{
typSetTime.week=0x20;
}break;
case 6:
{
typSetTime.week=0x40;
}break;
case 7:
{
typSetTime.week=0x01;
}break;
default:
{
typSetTime.week=0;
}break;
}
if(typSetTime.second!=set_time_old.second||typSetTime.minute!=set_time_old.minute||typSetTime.hour!=set_time_old.hour||typSetTime.week!=set_time_old.week||
typSetTime.day!=set_time_old.day||typSetTime.month!=set_time_old.month||typSetTime.year!=set_time_old.year)
{
buff_wr[0] = hex_2bcd(typSetTime.second);
buff_wr[1] = hex_2bcd(typSetTime.minute);
buff_wr[2] = hex_2bcd(typSetTime.hour);
buff_wr[3] = typSetTime.week;
buff_wr[4] = hex_2bcd(typSetTime.day);
buff_wr[5] = hex_2bcd(typSetTime.month);
buff_wr[6] = hex_2bcd(typSetTime.year);
for(i = 0;i < 7; i++)
{
WriteByteAdd(Rx8900sa_ADD,i,buff_wr[i]);
delay_ms(5);
}
set_time_old.second = typSetTime.second;
set_time_old.minute = typSetTime.minute;
set_time_old.hour = typSetTime.hour;
set_time_old.week = typSetTime.week;
set_time_old.day = typSetTime.day;
set_time_old.month = typSetTime.month;
set_time_old.year = typSetTime.year;
}
return 1;
}
/*
*@ Description: 设置闹钟--天设置方式
*@ param 1 ：例如：设置18号6点1分出发闹钟报警，则设置Rx8900sa_SetAlarmDay(1,6,18);
*@ param 2
*@ return
*/
uint16_t Rx8900sa_SetAlarmDay(uint8_t minute,uint8_t hour,uint8_t day)
{
uint8_t i;
uint8_t buff_wr[4];
typSetAlarmTime.minute = minute;
typSetAlarmTime.hour = hour;
typSetAlarmTime.day = day;
buff_wr[0] = hex_2bcd(typSetAlarmTime.minute);
buff_wr[1] = hex_2bcd(typSetAlarmTime.hour);
buff_wr[2] = hex_2bcd(typSetAlarmTime.day);
for(i = 8;i < 11; i++)
{
WriteByteAdd(Rx8900sa_ADD,i,buff_wr[i-8]);
delay_ms(5);
}
WriteByteAdd(Rx8900sa_ADD,15,0x08);//使能alarm中断信号AIE
delay_ms(5);
WriteByteAdd(Rx8900sa_ADD,13,0x40);//寄存器WADA:1设定day 0：设定week报警
delay_ms(5);
rx8900sa_ClearAlarmFlag(); //清除报警标志位
delay_ms(5);
return 1;
}
/*
*@ Description: 设置闹钟--周设置方式,WADA=0
*@ param 1 ：例如：设置星期一到星期五6点1分出发闹钟报警，则设置Rx8900sa_SetAlarmWeek(1,6,0x3E);
*@ param 2 ：week AE Sat Fri Th Wes Tue Mon Sun
*@ param 3 0 0 1 1 1 1 1 0 = 0x3E
*/
uint16_t Rx8900sa_SetAlarmWeek(uint8_t minute,uint8_t hour,uint8_t week)
{
uint8_t i;
uint8_t buff_wr[4];
typSetAlarmTime.minute = minute;
typSetAlarmTime.hour = hour;
typSetAlarmTime.week = week;
buff_wr[0] = hex_2bcd(typSetAlarmTime.minute);
buff_wr[1] = hex_2bcd(typSetAlarmTime.hour);
buff_wr[2] = typSetAlarmTime.week;
for(i = 8;i < 10; i++)
{
WriteByteAdd(Rx8900sa_ADD,i,buff_wr[i-8]);
delay_ms(5);
}
WriteByteAdd(Rx8900sa_ADD,10,buff_wr[2]);
delay_ms(5);
WriteByteAdd(Rx8900sa_ADD,15,0x08);//使能alarm中断信号AIE
delay_ms(5);
WriteByteAdd(Rx8900sa_ADD,13,0x00);//寄存器WADA:1设定day 0：设定week报警
delay_ms(5);
rx8900sa_ClearAlarmFlag(); //清除报警标志位
delay_ms(5);
return 1;
}
/*
*@ Description: 清除中断标志位AF
*@ param 1 ：时间到设定闹钟时间后触发报警引脚INT，电平会从高->低，清除标志位AF后，才会进行下次报警
*@ param 2
*@ return
*/
void rx8900sa_ClearAlarmFlag(void)
{
WriteByteAdd(Rx8900sa_ADD,14,0x40);//清除中断标志位AF,第3位AF清除，第6位保持
}
/*
*@ Description: 读取芯片闹钟寄存器，用于放在循环中做仿真测试使用
*@ param 1
*@ param 2
*@ return
*/
void Rx8900sa_ReadAlarm(void)
{
uint8_t buff_rd[3];
uint8_t i;
for(i = 8; i < 11;i ++)
{
buff_rd[i-8] = ReadByteAdd(Rx8900sa_ADD,i);
}
typGetAlarmTime.minute = ((buff_rd[0] >> 4) & 0x07) * 10 + (buff_rd[0] & 0x0f);
typGetAlarmTime.hour = ((buff_rd[1] >> 4) & 0x03) * 10 + (buff_rd[1] & 0x0f);
typGetAlarmTime.day = ((buff_rd[2] >> 4) & 0x03) * 10 + (buff_rd[2] & 0x0f);
typGetAlarmTime.week = buff_rd[2];
typGetAlarmTime.AF=ReadByteAdd(Rx8900sa_ADD,14);//读取中断标志寄存器，AF在第3位,0开始计数
typGetAlarmTime.AIE=ReadByteAdd(Rx8900sa_ADD,15);//读取AIE中断使能寄存器，AIE在第3位
typGetAlarmTime.WADA=ReadByteAdd(Rx8900sa_ADD,13);//读取WADA中断使能寄存器，WADA在第6位
if((typGetAlarmTime.AF&0x08)!=0) //产生闹钟中断，AF=1
{
rx8900sa_ClearAlarmFlag();
}
}
uint8_t GetNowtimeSecond(void)
{
return typNowTime.second;
}
uint8_t GetNowtimeMinute(void)
{
return typNowTime.minute;
}
uint8_t GetNowtimeHour(void)
{
return typNowTime.hour;
}
uint8_t GetNowtimeDay(void)
{
return typNowTime.day;
}
uint8_t GetNowtimeMonth(void)
{
return typNowTime.month;
}
uint8_t GetNowtimeYear(void)
{
return typNowTime.year;
}
/****************************
* 以下为I2C相关函数
*****************************/
/*时钟线状态设置*/
void Set_SCL(uint8_t x)
{
if(x)
{
SCL_H;
}
else
{
SCL_L;
}
delay_us(20);
}
/*数据线状态设置*/
void Set_SDA(uint8_t x)
{
if(x)
{
SDA_H;
}
else
{
SDA_L;
}
delay_us(20);
}
/*总线状态初始化*/
void I2Cstart(void)//开始信号
{
SDA_OUTPUT;
Set_SCL(1);
Set_SDA(1);
Set_SDA(0);
delay_us(20);
}
/*总线结束*/
void I2Cstop(void)
{
SDA_OUTPUT;
Set_SCL(0);
Set_SDA(0);
Set_SCL(1);
Set_SDA(1);
}
/*等待从机应答*/
void I2CResponseAck(void)
{
uint16_t i = 0;
Set_SCL(1);
SDA_INPUT;
while((SDA_X)&&(i<2500))
{
i++;//如果一段时间内没有收到应答信号，则认为已正确接收到数据?
}
Set_SCL(0);
}
void write_byte(uint8_t data)
{
uint8_t i;
SDA_OUTPUT;
for(i=0;i<8;i++)
{
Set_SCL(0);
if((data&0x80)!=0)
{
Set_SDA(1);
}
else
{
Set_SDA(0) ;
}
Set_SCL(1);
data=data<<1;
}
Set_SCL(0);
}
uint8_t read_byte(void)
{
uint8_t i,k;
Set_SCL(0);
SDA_INPUT;
for(i=0;i<8;i++)
{
k=k<<1;
Set_SCL(1);
if(SDA_X)
{
k=k|1;
}
Set_SCL(0);
}
return k;
}
/*主机应答回应*/
void I2CSendAck(uint8_t n)
{
Set_SCL(0);
SDA_OUTPUT;
if(n)
{
Set_SDA(1);
}
else
{
Set_SDA(0);
}
Set_SCL(1);
}
/*给IIC设备写入一个字节*/
void WriteByteAdd(uint8_t iic_add, uint8_t byte_add, uint8_t data)
{
I2Cstart();
write_byte(iic_add);
I2CResponseAck();
write_byte(byte_add);
I2CResponseAck();
write_byte(data);
I2CResponseAck();
I2Cstop();
}
/*读IIC设备一个字节*/
uint8_t ReadByteAdd(uint8_t iic_add, uint8_t byte_add)
{
uint8_t temp;
I2Cstart();
write_byte(iic_add);
I2CResponseAck();
write_byte(byte_add);
I2CResponseAck();
I2Cstart();
write_byte(iic_add|1);
I2CResponseAck();
temp = read_byte();
I2CSendAck(1);
I2Cstop();
return temp;
}
代码片.
#ifndef _RX8900SA_H
#define _RX8900SA_H
#define uint8_t unsigned char
#define uint16_t unsigned int
#define uint32_t unsigned long
#define Rx8900sa_ADD 0X64
typedef struct TIME_type
{
unsigned char second; //秒
unsigned char minute; //分
unsigned char hour; //小时
unsigned char week; //周
unsigned char day; //日
unsigned char month; //月
unsigned char year; //年
}TIME;
extern TIME typNowTime,typSetTime;
typedef struct ALARM_type
{
unsigned char minute; //分
unsigned char hour; //小时
unsigned char week; //周
unsigned char day; //日
unsigned char AF; //中断标志
unsigned char AIE; //中断使能
unsigned char WADA; //WADA:1设定day 0：设定week报警
}ALARM;
extern ALARM typSetAlarmTime,typGetAlarmTime;
// The two-wire I2C bus port
#define SCL BIT5
#define SCL_OUTPUT (P3DIR |= SCL)
#define SCL_L (P3OUT &=~SCL)
#define SCL_H (P3OUT |= SCL)
#define SDA BIT7
#define SDA_OUTPUT (P3DIR |= SDA)
#define SDA_INPUT (P3DIR &=~SDA)
#define SDA_L (P3OUT &=~SDA)
#define SDA_H (P3OUT |= SDA)
#define SDA_X (P3IN&SDA)
extern uint16_t Rx8900sa_SetNowTime(uint8_t second,uint8_t minute,uint8_t hour,uint8_t week,uint8_t day,uint8_t month,uint8_t year);
extern uint16_t Rx8900sa_SetAlarmDay(uint8_t minute,uint8_t hour,uint8_t day);
extern uint16_t Rx8900sa_SetAlarmWeek(uint8_t minute,uint8_t hour,uint8_t week);
extern uint8_t ReadByteAdd(uint8_t iic_add, uint8_t byte_add);
extern void WriteByteAdd(uint8_t iic_add, uint8_t byte_add, uint8_t data);
extern void Rx8900sa_ReadNowTime(void);
extern void Rx8900sa_ReadAlarm(void);
extern void rx8900sa_ClearAlarmFlag(void);
#endif