NXP LPC11xx I2C Slave 从机程序

/****************************************************************************
 *   $Id:: i2cslave.c 3635 2010-06-02 00:31:46Z usb00423                    $
 *   Project: NXP LPC11xx I2C Slave example
 *
 *   Description:
 *     This file contains I2C slave code example which include I2C slave
 *     initialization, I2C slave interrupt handler, and APIs for I2C slave
 *     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 "i2cslave.h"

volatile uint32_t I2CMasterState = I2C_IDLE;
volatile uint32_t I2CSlaveState = I2C_IDLE;

volatile uint32_t I2CMode;

volatile uint8_t I2CWrBuffer[BUFSIZE];
volatile uint8_t I2CRdBuffer[BUFSIZE];
volatile uint32_t I2CReadLength;
volatile uint32_t I2CWriteLength;

;
;

/*
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;

    /* this handler deals with master read and master write only */
    StatValue = LPC_I2C->STAT;
    switch ( StatValue )
    {
        case 0x60:/* An own SLA_W has been received. */
        case 0x68:
            RdIndex = ;
            LPC_I2C->CONSET = I2CONSET_AA;/* assert ACK after SLV_W is received */
            LPC_I2C->CONCLR = I2CONCLR_SIC;
            I2CSlaveState = I2C_WR_STARTED;
            break;
        case 0x80:/*  data receive */
        case 0x90:
            if ( I2CSlaveState == I2C_WR_STARTED )
            {
            I2CRdBuffer[RdIndex++] = LPC_I2C->DAT;
            LPC_I2C->CONSET = I2CONSET_AA;/* assert ACK after data is received */
            }
            else
            {
            LPC_I2C->CONCLR = I2CONCLR_AAC;/* assert NACK */
            }
            LPC_I2C->CONCLR = I2CONCLR_SIC;
            break;
        case 0xA8:/* An own SLA_R has been received. */
        case 0xB0:
            RdIndex = ;
            LPC_I2C->CONSET = I2CONSET_AA;/* assert ACK after SLV_R is received */
            LPC_I2C->CONCLR = I2CONCLR_SIC;
            I2CSlaveState = I2C_RD_STARTED;
            WrIndex = I2CRdBuffer[];/* The 1st byte is the index. */
            break;
        case 0xB8:/* Data byte has been transmitted */
        case 0xC8:
            if ( I2CSlaveState == I2C_RD_STARTED )
            {
             LPC_I2C->DAT = I2CRdBuffer[WrIndex+];/* write the same data back to master */
             WrIndex++;/* Need to skip the index byte in RdBuffer */
             LPC_I2C->CONSET = I2CONSET_AA;/* assert ACK  */
            }
            else
            {
             LPC_I2C->CONCLR = I2CONCLR_AAC;/* assert NACK  */
            }
            LPC_I2C->CONCLR = I2CONCLR_SIC;
            break;

        case 0xC0:/* Data byte has been transmitted, NACK */
            LPC_I2C->CONCLR = I2CONCLR_AAC;/* assert NACK  */
            LPC_I2C->CONCLR = I2CONCLR_SIC;
            I2CSlaveState = DATA_NACK;
            break;

        case 0xA0:/* Stop condition or repeated start has */
            LPC_I2C->CONSET = I2CONSET_AA;/* been received, assert ACK.  */
            LPC_I2C->CONCLR = I2CONCLR_SIC;
            I2CSlaveState = I2C_IDLE;
            break;

        default:
            LPC_I2C->CONCLR = I2CONCLR_SIC;
            LPC_I2C->CONSET = I2CONSET_I2EN | I2CONSET_SI;
            break;
    }
    return;
}

/*****************************************************************************
** Function name:I2CSlaveInit
**
** 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
**
*****************************************************************************/
void I2CSlaveInit( void )
{
    /* SSP and I2C reset are overlapped, a known bug,
    for now, both SSP and I2C use bit 0 for reset enable.
    Once the problem is fixed, change to "#if 1". */
#if 1
    LPC_SYSCON->PRESETCTRL |= ();
#else
    LPC_SYSCON->PRESETCTRL |= ();
#endif
    LPC_SYSCON->SYSAHBCLKCTRL |= (<<);
    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 */

    /*--- Clear flags ---*/
    LPC_I2C->CONCLR = I2CONCLR_AAC | I2CONCLR_SIC | I2CONCLR_STAC | I2CONCLR_I2ENC;    

    /*--- Reset registers ---*/
#if FAST_MODE_PLUS
    LPC_IOCON->PIO0_4 |= ();
    LPC_IOCON->PIO0_5 |= ();
    LPC_I2C->SCLL   = I2SCLL_HS_SCLL;
    LPC_I2C->SCLH   = I2SCLH_HS_SCLH;
#else
    LPC_I2C->SCLL   = I2SCLL_SCLL;
    LPC_I2C->SCLH   = I2SCLH_SCLH;
#endif

    LPC_I2C->ADR0 = PCF8594_ADDR;
    I2CSlaveState = I2C_IDLE;

    /* Enable the I2C Interrupt */
    NVIC_EnableIRQ(I2C_IRQn);

    LPC_I2C->CONSET = I2CONSET_I2EN | I2CONSET_SI;
    return;
}

/******************************************************************************
**                            End Of File
******************************************************************************/

/****************************************************************************
 *   $Id:: i2cslave.h 3635 2010-06-02 00:31:46Z usb00423                    $
 *   Project: NXP LPC11xx I2C Slave example
 *
 *   Description:
 *     This file contains I2C slave code header definition.
 *
 ****************************************************************************
 * 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.
****************************************************************************/
#ifndef __I2CSLAVE_H
#define __I2CSLAVE_H

#define FAST_MODE_PLUS      1

#define BUFSIZE             6
#define MAX_TIMEOUT         0x00FFFFFF

#define PCF8594_ADDR        0xA0
#define READ_WRITE          0x01

#define RD_BIT              0x01

#define I2C_IDLE            0
#define I2C_STARTED         1
#define I2C_RESTARTED       2
#define I2C_REPEATED_START  3
#define DATA_ACK            4
#define DATA_NACK           5
#define I2C_WR_STARTED      6
#define I2C_RD_STARTED      7

#define I2CONSET_I2EN       (0x1<<6)  /* I2C Control Set Register */
#define I2CONSET_AA         (0x1<<2)
#define I2CONSET_SI         (0x1<<3)
#define I2CONSET_STO        (0x1<<4)
#define I2CONSET_STA        (0x1<<5)

#define I2CONCLR_AAC        (0x1<<2)  /* I2C Control clear Register */
#define I2CONCLR_SIC        (0x1<<3)
#define I2CONCLR_STAC       (0x1<<5)
#define I2CONCLR_I2ENC      (0x1<<6)

#define I2DAT_I2C           0x00000000  /* I2C Data Reg */
#define I2ADR_I2C           0x00000000  /* I2C Slave Address Reg */
#define I2SCLH_SCLH         0x00000180  /* I2C SCL Duty Cycle High Reg */
#define I2SCLL_SCLL         0x00000180  /* I2C SCL Duty Cycle Low Reg */
#define I2SCLH_HS_SCLH      0x00000020  /* Fast Plus I2C SCL Duty Cycle High Reg */
#define I2SCLL_HS_SCLL      0x00000020  /* Fast Plus I2C SCL Duty Cycle Low Reg */

extern void I2C_IRQHandler( void );
extern void I2CSlaveInit( void );

#endif /* end __I2CSLAVE_H */
/****************************************************************************
**                            End Of File
*****************************************************************************/

/****************************************************************************
 *   $Id:: i2cslvtst.c 3635 2010-06-02 00:31:46Z usb00423                   $
 *   Project: NXP LPC11xx I2C example
 *
 *   Description:
 *     This file contains I2C slave test modules, main entry, to test I2C
 *     slave APIs.
 *
 ****************************************************************************
 * 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 "i2cslave.h"

extern volatile uint8_t I2CWrBuffer[BUFSIZE];
extern volatile uint8_t I2CRdBuffer[BUFSIZE];
extern volatile uint32_t I2CSlaveState;
extern volatile uint32_t I2CReadLength, I2CWriteLength;

/*******************************************************************************
**   Main Function  main()
*******************************************************************************/
int main (void)
{
    uint32_t i;

    SystemInit();

    ; i < BUFSIZE; i++ )
    {
        I2CRdBuffer[i] = 0x00;
    }

    I2CSlaveInit();/* initialize I2c */

    /* When the NACK occurs, the master has stopped the
    communication. Just check the content of I2CRd/WrBuffer. */
    while ( I2CSlaveState != DATA_NACK );
    ;
}

/******************************************************************************
**                            End Of File
******************************************************************************/