?? i2c.c
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/****************************************************************************
* $Id:: i2c.c 3662 2010-06-03 19:47:02Z usb00423 $
* Project: NXP LPC11xx I2C example
*
* Description:
* This file contains I2C code example which include I2C initialization,
* I2C interrupt handler, and APIs for I2C access.
*
****************************************************************************
* Software that is described herein is for illustrative purposes only
* which provides customers with programming information regarding the
* products. This software is supplied "AS IS" without any warranties.
* NXP Semiconductors assumes no responsibility or liability for the
* use of the software, conveys no license or title under any patent,
* copyright, or mask work right to the product. NXP Semiconductors
* reserves the right to make changes in the software without
* notification. NXP Semiconductors also make no representation or
* warranty that such application will be suitable for the specified
* use without further testing or modification.
****************************************************************************/
#include "LPC11xx.h" /* LPC11xx Peripheral Registers */
#include "type.h"
#include "i2c.h"
volatile uint32_t I2CMasterState = I2C_IDLE;
volatile uint32_t I2CSlaveState = I2C_IDLE;
volatile uint32_t timeout = 0;
volatile uint32_t I2CMode;
volatile uint8_t I2CMasterBuffer[IIC_BUFSIZE];
volatile uint8_t I2CSlaveBuffer [IIC_BUFSIZE];
volatile uint32_t I2CCount = 0;
volatile uint32_t I2CReadLength;
volatile uint32_t I2CWriteLength;
volatile uint32_t RdIndex = 0;
volatile uint32_t WrIndex = 0;
/*
From device to device, the I2C communication protocol may vary,
in the example below, the protocol uses repeated start to read data from or
write to the device:
For master read: the sequence is: STA,Addr(W),offset,RE-STA,Addr(r),data...STO
for master write: the sequence is: STA,Addr(W),offset,RE-STA,Addr(w),data...STO
Thus, in state 8, the address is always WRITE. in state 10, the address could
be READ or WRITE depending on the I2C command.
*/
/*****************************************************************************
** Function name: I2C_IRQHandler
**
** Descriptions: I2C interrupt handler, deal with master mode only.
**
** parameters: None
** Returned value: None
**
*****************************************************************************/
void I2C_IRQHandler(void)
{
uint8_t StatValue;
timeout = 0;
/* this handler deals with master read and master write only */
StatValue = LPC_I2C->STAT;
switch ( StatValue )
{
case 0x08: /* A Start condition is issued. */
WrIndex = 0;
LPC_I2C->DAT = I2CMasterBuffer[WrIndex++];
LPC_I2C->CONCLR = (I2CONCLR_SIC | I2CONCLR_STAC);
break;
case 0x10: /* A repeated started is issued */
RdIndex = 0;
/* Send SLA with R bit set, */
LPC_I2C->DAT = I2CMasterBuffer[WrIndex++];
LPC_I2C->CONCLR = (I2CONCLR_SIC | I2CONCLR_STAC);
break;
case 0x18: /* Regardless, it's a ACK */
if ( I2CWriteLength == 1 )
{
LPC_I2C->CONSET = I2CONSET_STO; /* Set Stop flag */
I2CMasterState = I2C_NO_DATA;
}
else
{
LPC_I2C->DAT = I2CMasterBuffer[WrIndex++];
}
LPC_I2C->CONCLR = I2CONCLR_SIC;
break;
case 0x28: /* Data byte has been transmitted, regardless ACK or NACK */
if ( WrIndex < I2CWriteLength )
{
LPC_I2C->DAT = I2CMasterBuffer[WrIndex++]; /* this should be the last one */
}
else
{
if ( I2CReadLength != 0 )
{
LPC_I2C->CONSET = I2CONSET_STA; /* Set Repeated-start flag */
}
else
{
LPC_I2C->CONSET = I2CONSET_STO; /* Set Stop flag */
I2CMasterState = I2C_OK;
}
}
LPC_I2C->CONCLR = I2CONCLR_SIC;
break;
case 0x30:
LPC_I2C->CONSET = I2CONSET_STO; /* Set Stop flag */
I2CMasterState = I2C_NACK_ON_DATA;
LPC_I2C->CONCLR = I2CONCLR_SIC;
break;
case 0x40: /* Master Receive, SLA_R has been sent */
if ( (RdIndex + 1) < I2CReadLength )
{
/* Will go to State 0x50 */
LPC_I2C->CONSET = I2CONSET_AA; /* assert ACK after data is received */
}
else
{
/* Will go to State 0x58 */
LPC_I2C->CONCLR = I2CONCLR_AAC; /* assert NACK after data is received */
}
LPC_I2C->CONCLR = I2CONCLR_SIC;
break;
case 0x50: /* Data byte has been received, regardless following ACK or NACK */
I2CSlaveBuffer[RdIndex++] = LPC_I2C->DAT;
if ( (RdIndex + 1) < I2CReadLength )
{
LPC_I2C->CONSET = I2CONSET_AA; /* assert ACK after data is received */
}
else
{
LPC_I2C->CONCLR = I2CONCLR_AAC; /* assert NACK on last byte */
}
LPC_I2C->CONCLR = I2CONCLR_SIC;
break;
case 0x58:
I2CSlaveBuffer[RdIndex++] = LPC_I2C->DAT;
I2CMasterState = I2C_OK;
LPC_I2C->CONSET = I2CONSET_STO; /* Set Stop flag */
LPC_I2C->CONCLR = I2CONCLR_SIC; /* Clear SI flag */
break;
case 0x20: /* regardless, it's a NACK */
case 0x48:
LPC_I2C->CONSET = I2CONSET_STO; /* Set Stop flag */
I2CMasterState = I2C_NACK_ON_ADDRESS;
LPC_I2C->CONCLR = I2CONCLR_SIC;
break;
case 0x38: /* Arbitration lost, in this example, we don't
deal with multiple master situation */
default:
I2CMasterState = I2C_ARBITRATION_LOST;
LPC_I2C->CONCLR = I2CONCLR_SIC;
break;
}
return;
}
/*****************************************************************************
** Function name: I2CStart
**
** Descriptions: Create I2C start condition, a timeout
** value is set if the I2C never gets started,
** and timed out. It's a fatal error.
**
** parameters: None
** Returned value: true or false, return false if timed out
**
*****************************************************************************/
uint32_t I2CStart( void )
{
uint32_t timeout = 0;
uint32_t retVal = FALSE;
/*--- Issue a start condition ---*/
LPC_I2C->CONSET = I2CONSET_STA; /* Set Start flag */
/*--- Wait until START transmitted ---*/
while( 1 )
{
if ( I2CMasterState == I2C_STARTED )
{
retVal = TRUE;
break;
}
if ( timeout >= MAX_TIMEOUT )
{
retVal = FALSE;
break;
}
timeout++;
}
return( retVal );
}
/*****************************************************************************
** Function name: I2CStop
**
** Descriptions: Set the I2C stop condition, if the routine
** never exit, it's a fatal bus error.
**
** parameters: None
** Returned value: true or never return
**
*****************************************************************************/
uint32_t I2CStop( void )
{
LPC_I2C->CONSET = I2CONSET_STO; /* Set Stop flag */
LPC_I2C->CONCLR = I2CONCLR_SIC; /* Clear SI flag */
/*--- Wait for STOP detected ---*/
while( LPC_I2C->CONSET & I2CONSET_STO );
return TRUE;
}
/*****************************************************************************
** Function name: I2CInit
**
** Descriptions: Initialize I2C controller
**
** parameters: I2c mode is either MASTER or SLAVE
** Returned value: true or false, return false if the I2C
** interrupt handler was not installed correctly
**
*****************************************************************************/
uint32_t I2CInit( uint32_t I2cMode )
{
LPC_SYSCON->PRESETCTRL |= (0x1<<1);
LPC_SYSCON->SYSAHBCLKCTRL |= (1<<5);
LPC_IOCON->PIO0_4 &= ~0x3F; /* I2C I/O config */
LPC_IOCON->PIO0_4 |= 0x01; /* I2C SCL */
LPC_IOCON->PIO0_5 &= ~0x3F;
LPC_IOCON->PIO0_5 |= 0x01; /* I2C SDA */
/* IOCON may change in the next release, save change for future references. */
// LPC_IOCON->PIO0_4 |= (0x1<<10); /* open drain pins */
// LPC_IOCON->PIO0_5 |= (0x1<<10); /* open drain pins */
/*--- Clear flags ---*/
LPC_I2C->CONCLR = I2CONCLR_AAC | I2CONCLR_SIC | I2CONCLR_STAC | I2CONCLR_I2ENC;
/*--- Reset registers ---*/
#if FAST_MODE_PLUS
LPC_IOCON->PIO0_4 |= (0x2<<8);
LPC_IOCON->PIO0_5 |= (0x2<<8);
LPC_I2C->SCLL = I2SCLL_HS_SCLL;
LPC_I2C->SCLH = I2SCLH_HS_SCLH;
#else
LPC_I2C->SCLL = I2SCLL_SCLL;
LPC_I2C->SCLH = I2SCLH_SCLH;
#endif
if ( I2cMode == I2CSLAVE )
{
LPC_I2C->ADR0 = CAT24C02_ADDR;
}
/* Enable the I2C Interrupt */
NVIC_EnableIRQ(I2C_IRQn);
LPC_I2C->CONSET = I2CONSET_I2EN;
return( TRUE );
}
/*****************************************************************************
** Function name: I2CEngine
**
** Descriptions: The routine to complete a I2C transaction
** from start to stop. All the intermitten
** steps are handled in the interrupt handler.
** Before this routine is called, the read
** length, write length, I2C master buffer,
** and I2C command fields need to be filled.
** see i2cmst.c for more details.
**
** parameters: None
** Returned value: true or false, return false only if the
** start condition can never be generated and
** timed out.
**
*****************************************************************************/
uint32_t I2CEngine( void )
{
RdIndex = 0;
WrIndex = 0;
/*--- Issue a start condition ---*/
LPC_I2C->CONSET = I2CONSET_STA; /* Set Start flag */
I2CMasterState = I2C_BUSY;
while ( I2CMasterState == I2C_BUSY )
{
if ( timeout >= MAX_TIMEOUT )
{
I2CMasterState = I2C_TIME_OUT;
break;
}
timeout++;
}
LPC_I2C->CONCLR = I2CONCLR_STAC;
return ( I2CMasterState );
}
/* 進(jìn)入并啟動(dòng)I2CEngine之前，配置好所有的參數(shù)包括寫數(shù)據(jù)長度，讀數(shù)據(jù)長度
I2C命令，初始化I2CMasterBuffer
(1)如果只寫，I2CWriteLength為寫入數(shù)據(jù)字節(jié)數(shù)，I2CReadLength讀長度為0，
所寫數(shù)據(jù)填入I2CMasterBuffer。
(2)如果只讀，I2CReadLength為讀數(shù)據(jù)字節(jié)數(shù)，I2CWriteLength為0。讀出
的數(shù)據(jù)填充至I2CSlaveBuffer。
(3)如果既有讀又有寫，I2CWriteLength指定寫入數(shù)據(jù)長度，I2CReadLength
指定讀取數(shù)據(jù)長度。
*/
/*****************************************************************
IIC寫1個(gè)字節(jié)
功 能： 向IIC設(shè)備指定地址寫一個(gè)字節(jié)
參 數(shù)： Dev_WR_Addr:設(shè)備地址
DataAddr :數(shù)據(jù)起始地址
Pdata :具體數(shù)據(jù)的指針
Len : 數(shù)據(jù)長度（字節(jié)為單位）
返回值： 無
*****************************************************************/
void I2C_WriteByte( uint8_t Dev_WR_Addr,uint8_t DataAddr,uint8_t Data )
{
uint32_t j;
I2CWriteLength = 3; //1字節(jié)設(shè)備地址、1字節(jié)數(shù)據(jù)地址、1字節(jié)具體數(shù)值
I2CReadLength = 0;
I2CMasterBuffer[0] = Dev_WR_Addr;
I2CMasterBuffer[1] = DataAddr;
I2CMasterBuffer[2] = Data;
I2CEngine();
for (j = 0; j < 0x20000; j++ ); //寫延遲
}
/*****************************************************************
24C08寫一頁16個(gè)字節(jié)
功 能： 向IIC設(shè)備指定地址寫n個(gè)字節(jié)
參 數(shù)： Pdata :具體數(shù)據(jù)的指針
Len :數(shù)據(jù)長度（字節(jié)為單位）
DataAddr :數(shù)據(jù)起始地址
Dev_WR_Addr:設(shè)備地址
返回值： 無
*****************************************************************/
void I2C_Write( volatile uint8_t *Pdata,uint8_t Len,uint8_t DataAddr,uint8_t Dev_WR_Addr)
{
uint8_t i;
uint32_t j;
I2CWriteLength = Len+2;
I2CReadLength = 0;
I2CMasterBuffer[0] = Dev_WR_Addr;
I2CMasterBuffer[1] = DataAddr;
for(i=0;i<Len;i++)
{
I2CMasterBuffer[i+2] = Pdata[i];
}
I2CEngine();
for (j = 0; j < 0x20000; j++ ); //寫延遲
}
/*****************************************************************
IIC讀1個(gè)字節(jié)
功 能： 在IIC設(shè)備內(nèi)部指定地址讀出一個(gè)字節(jié)
參 數(shù)： Dev_WR_Addr：設(shè)備地址
DataAddr ：內(nèi)部數(shù)據(jù)地址
返回值： 無
*****************************************************************/
uint8_t I2C_ReadByte( uint8_t Dev_WR_Addr,uint8_t DataAddr )
{
I2CWriteLength = 2; //1字節(jié)設(shè)備地址、1字節(jié)數(shù)據(jù)地址
I2CReadLength = 1; //讀1字節(jié)具體數(shù)值
I2CMasterBuffer[0] = Dev_WR_Addr;
I2CMasterBuffer[1] = DataAddr;
I2CMasterBuffer[2] = Dev_WR_Addr | RD_BIT;
I2CEngine();
return I2CSlaveBuffer[0];
}
/*****************************************************************
IIC讀N個(gè)字節(jié)(N<=64)
功 能： 在IIC設(shè)備內(nèi)部指定地址讀出N個(gè)字節(jié)
參 數(shù)： Pdata :具體數(shù)據(jù)的指針
Len :數(shù)據(jù)長度（字節(jié)為單位）
DataAddr :數(shù)據(jù)起始地址
Dev_WR_Addr:設(shè)備地址
返回值： 無
*****************************************************************/
void I2C_Read( volatile uint8_t *Pdata,uint8_t Len,uint8_t DataAddr,uint8_t Dev_WR_Addr )
{
uint32_t j;
I2CWriteLength = 2; //1字節(jié)設(shè)備地址、1字節(jié)數(shù)據(jù)地址
I2CReadLength = Len; //讀Len字節(jié)具體數(shù)值
I2CMasterBuffer[0] = Dev_WR_Addr;
I2CMasterBuffer[1] = DataAddr;
I2CMasterBuffer[2] = Dev_WR_Addr | RD_BIT;
I2CEngine();
for (j = 0; j < 0x20000; j++ ); // 等待讀完成
}
/**
* @}
*/
/**
* @}
*/
/************* (C) COPYRIGHT 2010 Wuhan R&D Center, Embest *****文件結(jié)束*******/
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