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