PIC24F之EEPROM读写中断事件处理函数要点及说明
2009年04月02日 22:57 发布者:hotpower
/*-------------------------------------------------------------------------------------------------PIC24F之EEPROM读写中断事件处理函数要点及说明
注意: 这是一个通用的I2C/SMBUS通讯中断处理程序
对于EEPROM来讲,从机后面需要跟EEPROM需要读写的地址(I2CRegs.RWAddr)
对于SMBUS来说,从机后面需要跟SMBUS需要的命令(I2CRegs.RWAddr改为I2CRegs.CMD即可)
由于PIC24F的I2C不太标准,I2C1STAT被搞得很倒塌!!!一点都没I2C的"大家闺秀"的样子~~~
不过它的STOP还能激活中断确实比LPCARM/AVR好一点点~~~
为什么I2C收发都用中断呢???
这主要是为了高低速灵活变化的总线通讯所做,主要是SMBUS总线的通信.
菜农在LPCARM/AVR上用此程序模板可谓不怕数据被干扰~~~
如果为I2cExit()也配上钩子函数,那么任何错误都在手掌中~~~
这个PIC程序虽没SMBUS的PEC校验部分,但"异步"还是完美的.
当然也要注意对写保护硬件管脚的控制时机的把握,原则是关保护的时间最短就更好~~~
菜农本来PIC24F菜鸟已“毕业”,但还是“忍痛”发表出来~~~
主要看到人们编写MCU程序太死板~~~特别是I2C程序.网上收发全中断的很少,可以说几乎没有.
随贴附老外倒塌的非中断I2C状态机读写程序i2cEmem.c~~~可以比较经典和非典的差异在何处~~~
菜农近期将整理出LPCARM和AVR的I2C/SMBUS/TWI/USI收发全中断实战例程供大家“游玩”~~~
如果精通DELPHI程序的人一定会为“事件驱动”机制而痴迷~~~为什么不在MCU上"声东击西"呢???
"有事件才处理"---这才是编程的硬道理~~~轮循的“痴迷等待”最终还是“单相思”~~~
本程序附实战结果图.(因为菜农的程序从来不空谈社会主义~~~)
原本是在"鸡蛋节"献给大家,由于"忆苦思甜"没发~~~就算是“臭蛋节”的礼物吧~~~
菜农 HotPower@126.com 2007.12.25 "鸡蛋节"于大雁塔菜地
--------------------------------------------------------------------------------------------------*/
#include "i2c.h"
_PERSISTENT volatile I2CREGS I2CRegs;
_PERSISTENT volatile I2CBITS I2CBits;
void I2cInit(void)
{
unsigned int i;
TRIS_WP = PORTOUTMODE;//定义WP为输出IO
TRIS_SCL1 = PORTOUTMODE;//定义SCL为输出IO
TRIS_SDA1 = PORTINPUTMODE;//定义SDA为输出入IO
ODC_SCL1 = 1;//OC输出
ODC_SDA1 = 1;//OC输出
WP = 1;//写保护
I2CRegs.MaxCount = 0x200;//8KByte
I2CRegs.I2CAddr = 0xa0;//器件地址
I2CRegs.RWAddr = 0;//EEPROM读写地址
I2CRegs.TxCount = 0;//发送数据字节个数
I2CRegs.RxCount = 0;//接收数据字节个数
for (i = 0; i < 16; i ++)
{
I2CRegs.TxBuffer = 0;//发送缓冲区清零
}
for (i = 0; i < 256; i ++)
{
I2CRegs.RxBuffer = 0;//接收缓冲区清零
}
I2C1CON = 0;
// I2C1CONbits.A10M = 0;//7位地址模式
I2C1CONbits.SCLREL = 1;
I2C1MSK = 0;
I2C1STAT = 0;
_MI2C1IF = 0;
_SI2C1IF = 0;
I2C1BRG = (FCY / (2 * I2CBAUD)) - 1;//波特率计算
/*------------------------------------------------------------------------
定义I2C串口2中断优先级位1111)
-------------------------------------------------------------------------*/
IPC4bits.MI2C1P0 = 1;
IPC4bits.MI2C1P1 = 1;
IPC4bits.MI2C1P2 = 1;
I2C1CONbits.I2CEN = 1;//允许I2C功能
_MI2C1IE = 1;//允许主设备中断
// I2cStop();
}
/*------------------------------------------------------------------
EEPROM读块函数(只能在回调函数I2CReadCallBack中得到读出的数据)
-------------------------------------------------------------------*/
void I2CReadBuffers(unsigned int E2RomAddr, unsigned int ReadSize)
{
if (ReadSize && (ReadSize <= 256))
{
I2CRegs.TxCount = 0;
I2CRegs.RxCount = ReadSize;
I2CRegs.RWAddr = E2RomAddr;
I2CRegs.I2CAddr |= 1;//0xa1
I2cStart();
}
}
void I2CReadByte(unsigned int E2RomAddr)
{
I2CRegs.TxCount = 0;
I2CRegs.RxCount = 1;
I2CRegs.RWAddr = E2RomAddr;
I2CRegs.I2CAddr |= 1;//0xa1
I2cStart();
}
/*------------------------------------------------------------------
EEPROM写块函数
-------------------------------------------------------------------*/
void I2CWriteBuffers(unsigned int E2RomAddr, unsigned int WriteSize)
{
if (WriteSize && (WriteSize <= 16))
{
I2CRegs.TxCount = WriteSize;
I2CRegs.RxCount = 0;
I2CRegs.RWAddr = E2RomAddr;
I2CRegs.I2CAddr &= 0xfe;//0xa0
I2cStart();
}
}
void I2CWriteByte(unsigned int E2RomAddr, unsigned char cData)
{
I2CRegs.TxBuffer = cData;
I2CRegs.TxCount = 1;
I2CRegs.RxCount = 0;
I2CRegs.RWAddr = E2RomAddr;
I2CRegs.I2CAddr &= 0xfe;//0xa0
I2cStart();
}
/*------------------------------------------------------------------
用户读回调函数
-------------------------------------------------------------------*/
void I2CReadCallBack(void)
{
if ((I2CRegs.RWAddr + I2CRegs.RxCount) <= I2CRegs.MaxCount)
{
// I2CRegs.RWAddr += I2CRegs.RxCount;
// I2CReadBuffers(I2CRegs.RWAddr, I2CRegs.RxCount);//继续读
}
}
/*------------------------------------------------------------------
用户写回调函数
-------------------------------------------------------------------*/
void I2CWriteCallBack(void)
{
if ((I2CRegs.RWAddr + I2CRegs.TxCount) <= I2CRegs.MaxCount)
{
// I2CRegs.RWAddr += I2CRegs.TxCount;
// I2CWriteBuffers(I2CRegs.RWAddr, I2CRegs.TxCount);//继续写
}
}
/*------------------------------------------------------------------
EEPROM读写启动函数
-------------------------------------------------------------------*/
void I2cStart(void)
{
/*------------------------------------------------------------------------
//本程序在状态I2C_MT_ADDRL_ACK下进行瞬间打开,也可在此打开,不过安全不好
if (I2CRegs.TxCount)//需要写入字节
{
WP = 0;//不写保护
}
else
{
WP = 1;//写保护
}
--------------------------------------------------------------------------*/
I2C1STATbits.IWCOL = 0;
I2CBits.BusyFlag = 1;
I2CRegs.State = I2C_START;//主机准备发送启始位
I2CRegs.Count = 0;//发送数据个数
I2CBits.I2CFlag = 0;
I2C1CONbits.SEN = 1;//发送Start信号
}
/*------------------------------------------------------------------
EEPROM读再启动函数
-------------------------------------------------------------------*/
void I2cReStart(void)
{
I2C1STATbits.IWCOL = 0;
I2CBits.BusyFlag = 1;
I2CRegs.State = I2C_REP_START;//主机准备发送重新启始位
I2CRegs.Count = 0;//发送数据个数
I2C1CONbits.RSEN = 1;//发送ReStart信号
I2C1CONbits.ACKEN = 0;
}
/*------------------------------------------------------------------
EEPROM读写正确停止函数
-------------------------------------------------------------------*/
void I2cStop(void)
{
I2C1STATbits.IWCOL = 0;
I2CBits.BusyFlag = 0;
I2CRegs.State = I2C_SUCCEEDED;//通讯成功
I2C1CONbits.PEN = 1;//发送Stop信号
WP = 1;//写保护
}
/*------------------------------------------------------------------
EEPROM读写错误退出函数
-------------------------------------------------------------------*/
void I2cExit(void)
{
I2C1STATbits.IWCOL = 0;
I2CBits.BusyFlag = 0;
I2CRegs.State = I2C_FAILED;
I2C1CONbits.PEN = 1;//发送Stop信号
WP = 1;//写保护
}
/*------------------------------------------------------------------
EEPROM读写中断事件处理函数(说明见文件头部)
-------------------------------------------------------------------*/
void I2CExec(void)
{
if (I2C1STATbits.S)//收到Start过信号
{
switch (I2CRegs.State)
{
case I2C_START://收到Start信号
I2C1TRN = I2CRegs.I2CAddr & 0xfe;//发送器件写地址(通知从机只能听)
I2CRegs.State = I2C_MT_SLA_ACK;//下次应该接收器件写地址应答信号
break;
case I2C_MT_SLA_ACK://收到器件写地址应答信号
if (!I2C1STATbits.ACKSTAT)//收到Ack信号
{
if (I2CRegs.MaxCount > 0x100)//EEPROM容量超过256个字节,EEPROM地址需要两次发送
{
I2C1TRN = I2CRegs.RWAddr >> 8;//发送EEPROM写高8位地址
I2CRegs.State = I2C_MT_ADDRH_ACK;//下次应该接收EEPROM写高8位地址应答信号
}
else//小容量只需一次发送!!!
{
I2C1TRN = I2CRegs.RWAddr;//发送EEPROM写低8位地址
I2CRegs.State = I2C_MT_ADDRL_ACK;//下次应该接收EEPROM写低8位地址应答信号
I2CRegs.Count = 0;//清空发送缓冲计数器
}
}
else//收到NAck信号
{
I2cExit();//错误的ACK信号
}
break;
case I2C_MT_ADDRH_ACK://收到EEPROM写高8位地址应答信号
if (!I2C1STATbits.ACKSTAT)//收到Ack信号
{
I2C1TRN = I2CRegs.RWAddr & 0xff;//发送EEPROM写低8位地址
I2CRegs.State = I2C_MT_ADDRL_ACK;//下次应该接收EEPROM写低8位地址应答信号
I2CRegs.Count = 0;//清空发送缓冲计数器
}
else//收到NAck信号
{
I2cExit();//错误的ACK信号
}
break;
case I2C_MT_ADDRL_ACK://收到EEPROM写高低8位地址应答信号
if (I2CRegs.TxCount)//写保护只在写入期间不保护,增加了对误写入的安全防护能力!!!
{
WP = 0;//不写保护
}
case I2C_MT_DATA_ACK://收到应答信号
if (!I2C1STATbits.ACKSTAT)//收到Ack信号
{
if (I2CRegs.Count < I2CRegs.TxCount)//缓冲区未空
{
I2C1TRN = I2CRegs.TxBuffer;//继续发送数据
}
else if (I2CRegs.Count == I2CRegs.TxCount)//缓冲区已空
{
if (I2CRegs.I2CAddr & 1)//应该开始接收数据
{
I2cReStart();//发送重复位命令
}
else//只写退出
{
I2cStop();//正常发送结束
}
}
else//干扰出错
{
I2cExit();//错误
}
}
else//收到NAck信号(可能被写保护)
{
I2cExit();//错误的ACK信号
}
break;
case I2C_REP_START://收到ReStart信号
I2C1TRN = I2CRegs.I2CAddr | I2C_READ;//发送器件读地址(通知从机可以说话)
I2CRegs.State = I2C_MR_SLA_ACK;//下次应该接收器件写读地址应答信号
break;
case I2C_MR_SLA_ACK://收到器件读地址应答信号
if (!I2C1STATbits.ACKSTAT)//收到Ack信号
{
I2C1CONbits.RCEN = 1;//开始接收数据
I2CRegs.State = I2C_MR_DATA;//下次应该收接收数据
}
else//收到NAck信号
{
I2cExit();//错误的ACK信号
}
break;
case I2C_MR_DATA://收到接收数据
if (I2CRegs.Count < I2CRegs.RxCount)
{
// I2C1STATbits.I2COV = 0;
I2CRegs.RxBuffer = I2C1RCV;
if (I2CRegs.Count < I2CRegs.RxCount)
{
I2C1CONbits.ACKDT = 0;//应答子机
I2CRegs.State = I2C_MR_DATA_EN;//下次应该收到器件允许继续读信号
}
else
{
I2C1CONbits.ACKDT = 1;//非应答子机
I2CRegs.State = I2C_MR_DATA_STOP;//下次应该收到退出信号
}
I2C1CONbits.ACKEN = 1;//向从机发送(非)应答信号
}
else//正确的状态已分支到I2C_MR_DATA_STOP
{
I2cExit();//错误
}
break;
case I2C_MR_DATA_EN://收到器件允许继续读信号
I2C1CONbits.RCEN = 1;//开始接收数据
I2CRegs.State = I2C_MR_DATA;//下次应该继续接收数据
break;
case I2C_MR_DATA_STOP://收到器件退出信号
I2cStop();//正常接收结束
break;
default://其他不可预料的错误
I2cExit();//错误
}
}
else if (I2C1STATbits.P)//收到Stop信号
{
if (I2CRegs.State == I2C_SUCCEEDED)//成功,回调
{
if (I2CRegs.I2CAddr & 1)//读
{
I2CBits.ReadFlag = 1;//激活用户读回调函数I2CReadCallBack()
}
else//写
{
I2CBits.WriteFlag = 1;//激活用户写回调函数I2CWriteCallBack()
}
}
}
else//无法确认的复杂错误
{
I2cExit();//错误出错退出
}
}
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hotpower 2009年04月02日
老外的i2cEmem.c
/**********************************************************************
* ?2005 Microchip Technology Inc.
*
* FileName: i2cEmem.c
* Dependencies: Header (.h) files if applicable, see below
* Processor: dsPIC33Fxxxx/PIC24Hxxxx
* Compiler: MPLAB?C30 v3.00 or higher
* Tested On: dsPIC33FJ256GP710
*
* SOFTWARE LICENSE AGREEMENT:
* Microchip Technology Incorporated ("Microchip") retains all ownership and
* intellectual property rights in the code accompanying this message and in all
* derivatives hereto. You may use this code, and any derivatives created by
* any person or entity by or on your behalf, exclusively with Microchip's
* proprietary products. Your acceptance and/or use of this code constitutes
* agreement to the terms and conditions of this notice.
*
* CODE ACCOMPANYING THIS MESSAGE IS SUPPLIED BY MICROCHIP "AS IS". NO
* WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT NOT LIMITED
* TO, IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE APPLY TO THIS CODE, ITS INTERACTION WITH MICROCHIP'S
* PRODUCTS, COMBINATION WITH ANY OTHER PRODUCTS, OR USE IN ANY APPLICATION.
*
* YOU ACKNOWLEDGE AND AGREE THAT, IN NO EVENT, SHALL MICROCHIP BE LIABLE, WHETHER
* IN CONTRACT, WARRANTY, TORT (INCLUDING NEGLIGENCE OR BREACH OF STATUTORY DUTY),
* STRICT LIABILITY, INDEMNITY, CONTRIBUTION, OR OTHERWISE, FOR ANY INDIRECT, SPECIAL,
* PUNITIVE, EXEMPLARY, INCIDENTAL OR CONSEQUENTIAL LOSS, DAMAGE, FOR COST OR EXPENSE OF
* ANY KIND WHATSOEVER RELATED TO THE CODE, HOWSOEVER CAUSED, EVEN IF MICROCHIP HAS BEEN
* ADVISED OF THE POSSIBILITY OR THE DAMAGES ARE FORESEEABLE. TO THE FULLEST EXTENT
* ALLOWABLE BY LAW, MICROCHIP'S TOTAL LIABILITY ON ALL CLAIMS IN ANY WAY RELATED TO
* THIS CODE, SHALL NOT EXCEED THE PRICE YOU PAID DIRECTLY TO MICROCHIP SPECIFICALLY TO
* HAVE THIS CODE DEVELOPED.
*
* You agree that you are solely responsible for testing the code and
* determining its suitability. Microchip has no obligation to modify, test,
* certify, or support the code.
*
* REVISION HISTORY:
*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Author Date Comments on this revision
*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Settu D. 07/09/06 First release of source file
*
**********************************************************************/
#if defined(__dsPIC33F__)
#include "p33Fxxxx.h"
#elif defined(__PIC24H__)
#include "p24Hxxxx.h"
#endif
#include "i2cEmem.h"
unsigned int jDone;
/*=============================================================================
I2C Master Interrupt Service Routine
=============================================================================*/
void __attribute__((interrupt, no_auto_psv)) _MI2C1Interrupt(void)
{
jDone=1;
IFS1bits.MI2C1IF = 0; //Clear the DMA0 Interrupt Flag;
}
/*=============================================================================
I2C Slave Interrupt Service Routine
=============================================================================*/
void __attribute__((interrupt, no_auto_psv)) _SI2C1Interrupt(void)
{
IFS1bits.SI2C1IF = 0; //Clear the DMA0 Interrupt Flag
}
/*=============================================================================
I2C Peripheral Initialisation
=============================================================================*/
void I2CEMEMinit(I2CEMEM_DRV *i2cMem)
{
i2cMem->cmd=0;
i2cMem->oData=0;
// Configre SCA/SDA pin as open-drain
ODCGbits.ODCG2=1;
ODCGbits.ODCG3=1;
I2C1CONbits.A10M=0;
I2C1CONbits.SCLREL=1;
I2C1BRG=300;
I2C1ADD=0;
I2C1MSK=0;
I2C1CONbits.I2CEN=1;
IEC1bits.MI2C1IE = 1;
IFS1bits.MI2C1IF = 0;
}
/*=============================================================================
I2C Serial EEPROM, STATE-MACHINE BASED DRIVER
=============================================================================*/
void I2CEMEMdrv(I2CEMEM_DRV *i2cMem)
{
static int state="0", cntr="0", rtrycntr="0";
switch(state)
{
case 0:
if( (i2cMem->cmd == I2C_WRITE) || (i2cMem->cmd == I2C_READ) )
state=1;
break;
/*==================================*/
/* Control/Address Phase */
/*==================================*/
case 1:
// Start Condition
I2C1CONbits.SEN=1;
state=state+1;
break;
case 2:
// Start Byte with device select id
if(jDone==1) {
jDone=0;
state=state+1;
I2C1TRN=(0x00A0)|(((i2cMem->oData->csel)&0x7)<<1);
}
break;
case 3:
// Send address byte 1, if ack is received. Else Retry
if(jDone==1) {
jDone=0;
if(I2C1STATbits.ACKSTAT==1) { // Ack Not received, Retry
if(rtrycntr < MAX_RETRY)
state=18;
else
state=16; // Flag error and exit
} else {
rtrycntr=0;
#if ADDRWIDTH==TWO_BYTE
I2C1TRN=((i2cMem->oData->addr)&0xFF00)>>8;
state=state+1;
#endif
#if ADDRWIDTH==ONE_BYTE
I2C1TRN=((i2cMem->oData->addr));
state=state+2;
#endif
}
}
break;
case 4:
// Send address byte 2, if ack is received. Else Flag error and exit
if(jDone==1) {
jDone=0;
if(I2C1STATbits.ACKSTAT==1) { // Ack Not received, Flag error and exit
state=16;
} else {
#if ADDRWIDTH==TWO_BYTE
I2C1TRN=((i2cMem->oData->addr)&0x00FF);
#endif
state=state+1;
}
}
break;
case 5:
// Read or Write
if(jDone==1) {
jDone=0;
if(I2C1STATbits.ACKSTAT==1) { // Ack Not received, Flag error and exit
state=16;
} else {
if(i2cMem->cmd == I2C_WRITE)
state=state+1;
if(i2cMem->cmd == I2C_READ)
state=8;
}
}
break;
/*==================================*/
/* Write Data Phase */
/*==================================*/
case 6:
// Send data
I2C1TRN=*(i2cMem->oData->buff + cntr);
state=state+1;
cntr=cntr+1;
break;
case 7:
// Look for end of data or no Ack
if(jDone==1) {
jDone=0;
state=state-1;
if(I2C1STATbits.ACKSTAT==1) { // Ack Not received, Flag error and exit
state=16;
} else {
if(cntr== i2cMem->oData->n)
state=14; // Close the Frame
}
}
break;
/*==================================*/
/* Read Data Phase */
/*==================================*/
case 8:
// Repeat Start
I2C1CONbits.RSEN=1;
state=state+1;
break;
case 9:
// Re-send control byte with W/R=R
if(jDone==1) {
jDone=0;
state=state+1;
I2C1TRN=(0x00A1)|(((i2cMem->oData->csel)&0x7)<<1);
}
break;
case 10:
// Check, if control byte went ok
if(jDone==1) {
jDone=0;
state=state+1;
if(I2C1STATbits.ACKSTAT==1) // Ack Not received, Flag error and exit
state=16;
}
break;
case 11:
// Receive Enable
I2C1CONbits.RCEN=1;
state++;
break;
case 12:
// Receive data
if(jDone==1) {
jDone=0;
state=state+1;
*(i2cMem->oData->buff+cntr)=I2C1RCV;
cntr++;
if(cntr== i2cMem->oData->n) {
I2C1CONbits.ACKDT=1; // No ACK
} else {
I2C1CONbits.ACKDT=0; // ACK
}
I2C1CONbits.ACKEN=1;
}
break;
case 13:
if(jDone==1) {
jDone=0;
if(cntr== i2cMem->oData->n)
state=state+1;
else
state=state-2;
}
break;
/*==================================*/
/* Stop Sequence */
/*==================================*/
case 14:
I2C1CONbits.PEN=1;
state++;
break;
case 15:
if(jDone==1) {
jDone=0;
state=0;
cntr=0;
i2cMem->cmd=0;
}
break;
/*==================================*/
/* Set Error */
/*==================================*/
case 16:
I2C1CONbits.PEN=1;
state++;
break;
case 17:
if(jDone==1) {
jDone=0;
state=0;
rtrycntr=0;
cntr=0;
i2cMem->cmd=0xFFFF;
}
break;
/*==================================*/
/* Retry */
/*==================================*/
case 18:
I2C1CONbits.PEN=1;
state++;
rtrycntr++;
break;
case 19:
if(jDone==1) {
jDone=0;
state=0;
cntr=0;
}
break;
}
}
老外的i2cEmem.c
/**********************************************************************
* ?2005 Microchip Technology Inc.
*
* FileName: i2cEmem.c
* Dependencies: Header (.h) files if applicable, see below
* Processor: dsPIC33Fxxxx/PIC24Hxxxx
* Compiler: MPLAB?C30 v3.00 or higher
* Tested On: dsPIC33FJ256GP710
*
* SOFTWARE LICENSE AGREEMENT:
* Microchip Technology Incorporated ("Microchip") retains all ownership and
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* REVISION HISTORY:
*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Author Date Comments on this revision
*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Settu D. 07/09/06 First release of source file
*
**********************************************************************/
#if defined(__dsPIC33F__)
#include "p33Fxxxx.h"
#elif defined(__PIC24H__)
#include "p24Hxxxx.h"
#endif
#include "i2cEmem.h"
unsigned int jDone;
/*=============================================================================
I2C Master Interrupt Service Routine
=============================================================================*/
void __attribute__((interrupt, no_auto_psv)) _MI2C1Interrupt(void)
{
jDone=1;
IFS1bits.MI2C1IF = 0; //Clear the DMA0 Interrupt Flag;
}
/*=============================================================================
I2C Slave Interrupt Service Routine
=============================================================================*/
void __attribute__((interrupt, no_auto_psv)) _SI2C1Interrupt(void)
{
IFS1bits.SI2C1IF = 0; //Clear the DMA0 Interrupt Flag
}
/*=============================================================================
I2C Peripheral Initialisation
=============================================================================*/
void I2CEMEMinit(I2CEMEM_DRV *i2cMem)
{
i2cMem->cmd=0;
i2cMem->oData=0;
// Configre SCA/SDA pin as open-drain
ODCGbits.ODCG2=1;
ODCGbits.ODCG3=1;
I2C1CONbits.A10M=0;
I2C1CONbits.SCLREL=1;
I2C1BRG=300;
I2C1ADD=0;
I2C1MSK=0;
I2C1CONbits.I2CEN=1;
IEC1bits.MI2C1IE = 1;
IFS1bits.MI2C1IF = 0;
}
/*=============================================================================
I2C Serial EEPROM, STATE-MACHINE BASED DRIVER
=============================================================================*/
void I2CEMEMdrv(I2CEMEM_DRV *i2cMem)
{
static int state="0", cntr="0", rtrycntr="0";
switch(state)
{
case 0:
if( (i2cMem->cmd == I2C_WRITE) || (i2cMem->cmd == I2C_READ) )
state=1;
break;
/*==================================*/
/* Control/Address Phase */
/*==================================*/
case 1:
// Start Condition
I2C1CONbits.SEN=1;
state=state+1;
break;
case 2:
// Start Byte with device select id
if(jDone==1) {
jDone=0;
state=state+1;
I2C1TRN=(0x00A0)|(((i2cMem->oData->csel)&0x7)<<1);
}
break;
case 3:
// Send address byte 1, if ack is received. Else Retry
if(jDone==1) {
jDone=0;
if(I2C1STATbits.ACKSTAT==1) { // Ack Not received, Retry
if(rtrycntr < MAX_RETRY)
state=18;
else
state=16; // Flag error and exit
} else {
rtrycntr=0;
#if ADDRWIDTH==TWO_BYTE
I2C1TRN=((i2cMem->oData->addr)&0xFF00)>>8;
state=state+1;
#endif
#if ADDRWIDTH==ONE_BYTE
I2C1TRN=((i2cMem->oData->addr));
state=state+2;
#endif
}
}
break;
case 4:
// Send address byte 2, if ack is received. Else Flag error and exit
if(jDone==1) {
jDone=0;
if(I2C1STATbits.ACKSTAT==1) { // Ack Not received, Flag error and exit
state=16;
} else {
#if ADDRWIDTH==TWO_BYTE
I2C1TRN=((i2cMem->oData->addr)&0x00FF);
#endif
state=state+1;
}
}
break;
case 5:
// Read or Write
if(jDone==1) {
jDone=0;
if(I2C1STATbits.ACKSTAT==1) { // Ack Not received, Flag error and exit
state=16;
} else {
if(i2cMem->cmd == I2C_WRITE)
state=state+1;
if(i2cMem->cmd == I2C_READ)
state=8;
}
}
break;
/*==================================*/
/* Write Data Phase */
/*==================================*/
case 6:
// Send data
I2C1TRN=*(i2cMem->oData->buff + cntr);
state=state+1;
cntr=cntr+1;
break;
case 7:
// Look for end of data or no Ack
if(jDone==1) {
jDone=0;
state=state-1;
if(I2C1STATbits.ACKSTAT==1) { // Ack Not received, Flag error and exit
state=16;
} else {
if(cntr== i2cMem->oData->n)
state=14; // Close the Frame
}
}
break;
/*==================================*/
/* Read Data Phase */
/*==================================*/
case 8:
// Repeat Start
I2C1CONbits.RSEN=1;
state=state+1;
break;
case 9:
// Re-send control byte with W/R=R
if(jDone==1) {
jDone=0;
state=state+1;
I2C1TRN=(0x00A1)|(((i2cMem->oData->csel)&0x7)<<1);
}
break;
case 10:
// Check, if control byte went ok
if(jDone==1) {
jDone=0;
state=state+1;
if(I2C1STATbits.ACKSTAT==1) // Ack Not received, Flag error and exit
state=16;
}
break;
case 11:
// Receive Enable
I2C1CONbits.RCEN=1;
state++;
break;
case 12:
// Receive data
if(jDone==1) {
jDone=0;
state=state+1;
*(i2cMem->oData->buff+cntr)=I2C1RCV;
cntr++;
if(cntr== i2cMem->oData->n) {
I2C1CONbits.ACKDT=1; // No ACK
} else {
I2C1CONbits.ACKDT=0; // ACK
}
I2C1CONbits.ACKEN=1;
}
break;
case 13:
if(jDone==1) {
jDone=0;
if(cntr== i2cMem->oData->n)
state=state+1;
else
state=state-2;
}
break;
/*==================================*/
/* Stop Sequence */
/*==================================*/
case 14:
I2C1CONbits.PEN=1;
state++;
break;
case 15:
if(jDone==1) {
jDone=0;
state=0;
cntr=0;
i2cMem->cmd=0;
}
break;
/*==================================*/
/* Set Error */
/*==================================*/
case 16:
I2C1CONbits.PEN=1;
state++;
break;
case 17:
if(jDone==1) {
jDone=0;
state=0;
rtrycntr=0;
cntr=0;
i2cMem->cmd=0xFFFF;
}
break;
/*==================================*/
/* Retry */
/*==================================*/
case 18:
I2C1CONbits.PEN=1;
state++;
rtrycntr++;
break;
case 19:
if(jDone==1) {
jDone=0;
state=0;
cntr=0;
}
break;
}
}
对应的I2C.H
#include "main.h"
#ifndef __I2C_H
#define __I2C_H
#define I2CBAUD 800000//800KHz 本程序是读写铁电的,故速度很高
//下面的是I2C的标准状态表,因为PIC的不标准,故凑合着用和补充了加注解的部分~~~
enum enum_I2CState
{
/* Master */
I2C_START = 0x08,//启动
I2C_REP_START= 0x10,//重启动
/* Master Transmitter */
I2C_MT_SLA_ACK= 0x18,//主发模式下得到从机地址应答信号
I2C_MT_SLA_NACK= 0x20,
I2C_MT_DATA_ACK= 0x28,//主发模式下得到从机数据应答信号
I2C_MT_DATA_NACK= 0x30,
I2C_MT_ARB_LOST= 0x38,
/* Master Receiver */
I2C_MR_ARB_LOST= 0x38,
I2C_MR_SLA_ACK= 0x40,//主收模式下得到从机地址应答信号
I2C_MR_SLA_NACK= 0x48,
I2C_MR_DATA_ACK= 0x50,
I2C_MR_DATA_NACK= 0x58,
/* Slave Transmitter */
I2C_ST_SLA_ACK= 0xA8,
I2C_ST_ARB_LOST_SLA_ACK= 0xB0,
I2C_ST_DATA_ACK= 0xB8,
I2C_ST_DATA_NACK= 0xC0,
I2C_ST_LAST_DATA= 0xC8,
/* Slave Receiver */
I2C_SR_SLA_ACK= 0x60,
I2C_SR_ARB_LOST_SLA_ACK= 0x68,
I2C_SR_GCALL_ACK= 0x70,
I2C_SR_ARB_LOST_GCALL_ACK= 0x78,
I2C_SR_DATA_ACK= 0x80,
I2C_SR_DATA_NACK= 0x88,
I2C_SR_GCALL_DATA_ACK= 0x90,
I2C_SR_GCALL_DATA_NACK= 0x98,
I2C_SR_STOP= 0xA0,
/* Misc */
I2C_NO_INFO= 0xF8,
I2C_MT_ADDRH_ACK= 0x3a,//主发模式下得到从机高位EEPROM地址应答信号
I2C_MT_ADDRL_ACK= 0x3b,//主发模式下得到从机高低位EEPROM地址应答信号
I2C_MR_DATA= 0x5a,//主收模式下接收数据
I2C_MR_DATA_EN= 0x5b,//主收模式下使能接收数据功能
I2C_MR_DATA_STOP= 0x5c,//主收模式下接收数据完成
I2C_FAILED= 0xcc,//读写操作失败
I2C_SUCCEEDED= 0x00,//读写操作成功
I2C_RWBIT= 0,//
I2C_READ= 1,//
I2C_WRITE= 0//
};
#define TRIS_SCL1 _TRISG2 //SCL方向控制
#define TRIS_SDA1 _TRISG3 //SDA方向控制
#define ODC_SCL1 _ODG2 //SCL开漏控制
#define ODC_SDA1 _ODG3 //SDA开漏控制
/*-----------------------------------------
写保护管脚定义,需要硬件的支持
------------------------------------------*/
#define TRIS_WP _TRISD0 //WP方向控制
#define WP _LATD0//写保护
typedef struct tagI2CBITS
{
union
{
unsigned char I2CFlag;
struct
{
unsigned char BusyFlag: 1;//忙标志
unsigned char ReadFlag: 1;//读回调标志
unsigned char WriteFlag: 1;//写回调标志
};
};
}I2CBITS;
extern volatile I2CBITS I2CBits;
typedef struct tagI2CREGS
{
unsigned char State;//运行状态编码
unsigned char I2CAddr;//器件地址0xa1,0xa0
unsigned int RWAddr;//器件读写地址(自动根据MaxCount判断长短地址)
unsigned int Count;//运行计数器
unsigned int TxCount;//发送(写)个数
unsigned int RxCount;//接收(读)个数
unsigned int MaxCount;//器件最大容量
unsigned char TxBuffer;//发送缓冲区
unsigned char RxBuffer;//接收缓冲区
}I2CREGS;
extern volatile I2CREGS I2CRegs;
void I2cInit(void);
void I2CReadBuffers(unsigned int, unsigned int);
void I2CReadByte(unsigned int);
void I2CWriteBuffers(unsigned int, unsigned int);
void I2CWriteByte(unsigned int, unsigned char);
void I2CReadCallBack(void);
void I2CWriteCallBack(void);
void I2cStart(void);
void I2cReStart(void);
void I2cStop(void);
void I2CExec(void);
#endif//__I2C_H