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twi.h

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/*
   twi.h - definitions for TWI: Two-Wire Interface or Twi Was I2c(tm).

   Contributors:
     Created by Marek Michalkiewicz <marekm@linux.org.pl>

   THIS SOFTWARE IS NOT COPYRIGHTED

   This source code is offered for use in the public domain.  You may
   use, modify or distribute it freely.

   This code is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY.  ALL WARRANTIES, EXPRESS OR IMPLIED ARE HEREBY
   DISCLAIMED.  This includes but is not limited to warranties of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

   Based on advance information Atmel datasheet Rev. 1142A-10/00 (ATmega163).
 */

#ifndef _TWI_H_
#define _TWI_H_ 1

/* TWSR values (not bits) */
/* Master */
#define TW_START                0x08
#define TW_REP_START            0x10
/* Master Transmitter */
#define TW_MT_SLA_ACK           0x18
#define TW_MT_SLA_NACK          0x20
#define TW_MT_DATA_ACK          0x28
#define TW_MT_DATA_NACK         0x30
#define TW_MT_ARB_LOST          0x38
/* Master Receiver */
#define TW_MR_ARB_LOST          0x38
#define TW_MR_SLA_ACK           0x40
#define TW_MR_SLA_NACK          0x48
#define TW_MR_DATA_ACK          0x50
#define TW_MR_DATA_NACK         0x58
/* Slave Transmitter */
#define TW_ST_SLA_ACK           0xA8
#define TW_ST_ARB_LOST_SLA_ACK  0xB0
#define TW_ST_DATA_ACK          0xB8
#define TW_ST_DATA_NACK         0xC0
#define TW_ST_LAST_DATA         0xC8
/* Slave Receiver */
#define TW_SR_SLA_ACK           0x60
#define TW_SR_ARB_LOST_SLA_ACK  0x68
#define TW_SR_GCALL_ACK         0x70
#define TW_SR_ARB_LOST_GCALL_ACK 0x78
#define TW_SR_DATA_ACK          0x80
#define TW_SR_DATA_NACK         0x88
#define TW_SR_GCALL_DATA_ACK    0x90
#define TW_SR_GCALL_DATA_NACK   0x98
#define TW_SR_STOP              0xA0
/* Misc */
#define TW_NO_INFO              0xF8
#define TW_BUS_ERROR            0x00

#endif  /* _TWI_H_ */

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