Subversion Repositories openrisc

/* ----------------------------------------------------------------------------

 *         ATMEL Microcontroller Software Support

 * ----------------------------------------------------------------------------

 * Copyright (c) 2008, Atmel Corporation

 *

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 * - Redistributions of source code must retain the above copyright notice,

 * this list of conditions and the disclaimer below.

 *

 * Atmel's name may not be used to endorse or promote products derived from

 * this software without specific prior written permission.

 *

 * DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF

 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE

 * DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,

 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,

 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 * ----------------------------------------------------------------------------

 */

//------------------------------------------------------------------------------

/// \unit

///

/// !Purpose

///

/// Interface for configuration the Two Wire Interface (TWI) peripheral.

///

/// !Usage

///

/// -# Configures a TWI peripheral to operate in master mode, at the given

/// frequency (in Hz) using TWI_ConfigureMaster().

/// -# or if hardware possible, configures a TWI peripheral to operate in 

/// slave mode, at the given frequency (in Hz) using TWI_ConfigureSlave().

/// -# Sends a STOP condition on the TWI using TWI_Stop().

/// -# Starts a read operation on the TWI bus with the specified slave using

/// TWI_StartRead(). Data must then be read using TWI_ReadByte() whenever 

/// a byte is available (poll using TWI_ByteReceived()).

/// -# Starts a write operation on the TWI to access the selected slave using

/// TWI_StartWrite(). A byte of data must be provided to start the write;

/// other bytes are written next. 

/// -# Sends a byte of data to one of the TWI slaves on the bus using TWI_WriteByte().

/// This function must be called once before TWI_StartWrite() with the first byte of data

/// to send, then it shall be called repeatedly after that to send the remaining bytes.

/// -# Check if a byte has been received and can be read on the given TWI

/// peripheral using TWI_ByteReceived(). 

/// Check if a byte has been sent using TWI_ByteSent().

/// -# Check if the current transmission is complete (the STOP has been sent)

/// using TWI_TransferComplete().

/// -# Enables & disable the selected interrupts sources on a TWI peripheral

/// using TWI_EnableIt() and TWI_DisableIt().

/// -# Get current status register of the given TWI peripheral using

/// TWI_GetStatus(). Get current status register of the given TWI peripheral, but

/// masking interrupt sources which are not currently enabled using 

/// TWI_GetMaskedStatus().

//------------------------------------------------------------------------------

#ifndef TWI_H

#define TWI_H

//------------------------------------------------------------------------------

//         Headers

//------------------------------------------------------------------------------

#include <board.h>

//------------------------------------------------------------------------------

//         Global definitions

//------------------------------------------------------------------------------

// Missing AT91C_TWI_TXRDY definition.

#ifndef AT91C_TWI_TXRDY

    #define AT91C_TWI_TXRDY   AT91C_TWI_TXRDY_MASTER

#endif

// Missing AT91C_TWI_TXCOMP definition.

#ifndef AT91C_TWI_TXCOMP

    #define AT91C_TWI_TXCOMP  AT91C_TWI_TXCOMP_MASTER

#endif

//------------------------------------------------------------------------------

//         Global macros

//------------------------------------------------------------------------------

/// Returns 1 if the TXRDY bit (ready to transmit data) is set in the given

/// status register value.

#define TWI_STATUS_TXRDY(status) ((status & AT91C_TWI_TXRDY) == AT91C_TWI_TXRDY)

/// Returns 1 if the RXRDY bit (ready to receive data) is set in the given

/// status register value.

#define TWI_STATUS_RXRDY(status) ((status & AT91C_TWI_RXRDY) == AT91C_TWI_RXRDY)

/// Returns 1 if the TXCOMP bit (transfer complete) is set in the given

/// status register value.

#define TWI_STATUS_TXCOMP(status) ((status & AT91C_TWI_TXCOMP) == AT91C_TWI_TXCOMP)

//------------------------------------------------------------------------------

//         Global functions

//------------------------------------------------------------------------------

extern void TWI_ConfigureMaster(AT91S_TWI *pTwi, unsigned int twck, unsigned int mck);

#ifdef AT91C_TWI_SVEN  // TWI slave

extern void TWI_ConfigureSlave(AT91S_TWI *pTwi, unsigned char slaveAddress);

#endif

extern void TWI_Stop(AT91S_TWI *pTwi);

extern void TWI_StartRead(

    AT91S_TWI *pTwi,

    unsigned char address,

    unsigned int iaddress,

    unsigned char isize);

extern unsigned char TWI_ReadByte(AT91S_TWI *pTwi);

extern void TWI_WriteByte(AT91S_TWI *pTwi, unsigned char byte);

extern void TWI_StartWrite(

    AT91S_TWI *pTwi,

    unsigned char address,

    unsigned int iaddress,

    unsigned char isize,

    unsigned char byte);

extern unsigned char TWI_ByteReceived(AT91S_TWI *pTwi);

extern unsigned char TWI_ByteSent(AT91S_TWI *pTwi);

extern unsigned char TWI_TransferComplete(AT91S_TWI *pTwi);

extern void TWI_EnableIt(AT91S_TWI *pTwi, unsigned int sources);

extern void TWI_DisableIt(AT91S_TWI *pTwi, unsigned int sources);

extern unsigned int TWI_GetStatus(AT91S_TWI *pTwi);

extern unsigned int TWI_GetMaskedStatus(AT91S_TWI *pTwi);

extern void TWI_SendSTOPCondition(AT91S_TWI *pTwi);

#endif //#ifndef TWI_H