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/*****************************************************************************
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*
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* Atmel Corporation
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*
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* File              : TWI_Slave.h
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* Compiler          : IAR EWAAVR 2.28a/3.10c
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* Revision          : $Revision: 2475 $
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* Date              : $Date: 2007-09-20 12:00:43 +0200 (to, 20 sep 2007) $
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* Updated by        : $Author: mlarsson $
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*
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* Support mail      : avr@atmel.com
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*
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* Supported devices : All devices with a TWI module can be used.
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*                     The example is written for the ATmega16
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*
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* AppNote           : AVR311 - TWI Slave Implementation
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*
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* Description       : Header file for TWI_slave.c
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*                     Include this file in the application.
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*
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****************************************************************************/
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/*! \page MISRA
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 *
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 * General disabling of MISRA rules:
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 * * (MISRA C rule 1) compiler is configured to allow extensions
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 * * (MISRA C rule 111) bit fields shall only be defined to be of type unsigned int or signed int
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 * * (MISRA C rule 37) bitwise operations shall not be performed on signed integer types
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 * As it does not work well with 8bit architecture and/or IAR
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 * Other disabled MISRA rules
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 * * (MISRA C rule 109) use of union - overlapping storage shall not be used
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 * * (MISRA C rule 61) every non-empty case clause in a switch statement shall be terminated with a break statement
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*/
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/****************************************************************************
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  TWI Status/Control register definitions
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****************************************************************************/
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#define TWI_BUFFER_SIZE 4      // Reserves memory for the drivers transceiver buffer.
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                               // Set this to the largest message size that will be sent including address byte.
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/****************************************************************************
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  Global definitions
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****************************************************************************/
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union TWI_statusReg_t                       // Status byte holding flags.
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{
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    unsigned char all;
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    struct
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    {
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        unsigned char lastTransOK:1;      
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        unsigned char RxDataInBuf:1;
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        unsigned char genAddressCall:1;                        // TRUE = General call, FALSE = TWI Address;
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        unsigned char unusedBits:5;
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    };
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};
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extern union TWI_statusReg_t TWI_statusReg;
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/****************************************************************************
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  Function definitions
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****************************************************************************/
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void twi_slave_init( unsigned char );
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unsigned char twi_slave_busy( void );
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unsigned char twi_slave_get_status( void );
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void twi_slave_start_with_data( unsigned char * , unsigned char );
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void twi_slave_start( void );
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unsigned char twi_slave_get_data( unsigned char *, unsigned char );
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/****************************************************************************
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  Bit and byte definitions
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****************************************************************************/
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#define TWI_READ_BIT  0   // Bit position for R/W bit in "address byte".
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#define TWI_ADR_BITS  1   // Bit position for LSB of the slave address bits in the init byte.
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#define TWI_GEN_BIT   0   // Bit position for LSB of the general call bit in the init byte.
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#define TRUE          1
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#define FALSE         0
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/****************************************************************************
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  TWI State codes
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****************************************************************************/
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// General TWI Master staus codes                      
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#define TWI_START                  0x08  // START has been transmitted  
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#define TWI_REP_START              0x10  // Repeated START has been transmitted
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#define TWI_ARB_LOST               0x38  // Arbitration lost
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// TWI Master Transmitter staus codes                      
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#define TWI_MTX_ADR_ACK            0x18  // SLA+W has been tramsmitted and ACK received
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#define TWI_MTX_ADR_NACK           0x20  // SLA+W has been tramsmitted and NACK received
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#define TWI_MTX_DATA_ACK           0x28  // Data byte has been tramsmitted and ACK received
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#define TWI_MTX_DATA_NACK          0x30  // Data byte has been tramsmitted and NACK received
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// TWI Master Receiver staus codes  
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#define TWI_MRX_ADR_ACK            0x40  // SLA+R has been tramsmitted and ACK received
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#define TWI_MRX_ADR_NACK           0x48  // SLA+R has been tramsmitted and NACK received
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#define TWI_MRX_DATA_ACK           0x50  // Data byte has been received and ACK tramsmitted
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#define TWI_MRX_DATA_NACK          0x58  // Data byte has been received and NACK tramsmitted
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// TWI Slave Transmitter staus codes
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#define TWI_STX_ADR_ACK            0xA8  // Own SLA+R has been received; ACK has been returned
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#define TWI_STX_ADR_ACK_M_ARB_LOST 0xB0  // Arbitration lost in SLA+R/W as Master; own SLA+R has been received; ACK has been returned
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#define TWI_STX_DATA_ACK           0xB8  // Data byte in TWDR has been transmitted; ACK has been received
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#define TWI_STX_DATA_NACK          0xC0  // Data byte in TWDR has been transmitted; NOT ACK has been received
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#define TWI_STX_DATA_ACK_LAST_BYTE 0xC8  // Last data byte in TWDR has been transmitted (TWEA = �0�); ACK has been received
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// TWI Slave Receiver staus codes
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#define TWI_SRX_ADR_ACK            0x60  // Own SLA+W has been received ACK has been returned
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#define TWI_SRX_ADR_ACK_M_ARB_LOST 0x68  // Arbitration lost in SLA+R/W as Master; own SLA+W has been received; ACK has been returned
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#define TWI_SRX_GEN_ACK            0x70  // General call address has been received; ACK has been returned
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#define TWI_SRX_GEN_ACK_M_ARB_LOST 0x78  // Arbitration lost in SLA+R/W as Master; General call address has been received; ACK has been returned
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#define TWI_SRX_ADR_DATA_ACK       0x80  // Previously addressed with own SLA+W; data has been received; ACK has been returned
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#define TWI_SRX_ADR_DATA_NACK      0x88  // Previously addressed with own SLA+W; data has been received; NOT ACK has been returned
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#define TWI_SRX_GEN_DATA_ACK       0x90  // Previously addressed with general call; data has been received; ACK has been returned
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#define TWI_SRX_GEN_DATA_NACK      0x98  // Previously addressed with general call; data has been received; NOT ACK has been returned
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#define TWI_SRX_STOP_RESTART       0xA0  // A STOP condition or repeated START condition has been received while still addressed as Slave
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// TWI Miscellaneous status codes
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#define TWI_NO_STATE               0xF8  // No relevant state information available; TWINT = �0�
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#define TWI_BUS_ERROR              0x00  // Bus error due to an illegal START or STOP condition