util_twi(3)

NAME
util_twi - <util/twi.h>: TWI bit mask definitions

  TWSR values
Mnemonics:
TW_MT_xxx - master transmitter
TW_MR_xxx - master receiver
TW_ST_xxx - slave transmitter
TW_SR_xxx - slave receiver
#define TW_START 0x08
#define TW_REP_START 0x10
#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
#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
#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
#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
#define TW_NO_INFO 0xF8
#define TW_BUS_ERROR 0x00
#define TW_STATUS_MASK
#define TW_STATUS (TWSR & TW_STATUS_MASK)

  R/~W bit in SLA+R/W address field.
#define TW_READ 1
#define TW_WRITE 0

Detailed Description

#include <util/twi.h>

This header file contains bit mask definitions for use with the AVR TWI interface.

Macro Definition Documentation

  #define TW_BUS_ERROR 0x00
illegal start or stop condition

  #define TW_MR_ARB_LOST 0x38
arbitration lost in SLA+R or NACK

  #define TW_MR_DATA_ACK 0x50
data received, ACK returned

  #define TW_MR_DATA_NACK 0x58
data received, NACK returned

  #define TW_MR_SLA_ACK 0x40
SLA+R transmitted, ACK received

  #define TW_MR_SLA_NACK 0x48
SLA+R transmitted, NACK received

  #define TW_MT_ARB_LOST 0x38
arbitration lost in SLA+W or data

  #define TW_MT_DATA_ACK 0x28
data transmitted, ACK received

  #define TW_MT_DATA_NACK 0x30
data transmitted, NACK received

  #define TW_MT_SLA_ACK 0x18
SLA+W transmitted, ACK received

  #define TW_MT_SLA_NACK 0x20
SLA+W transmitted, NACK received

  #define TW_NO_INFO 0xF8
no state information available

  #define TW_READ 1
SLA+R address

  #define TW_REP_START 0x10
repeated start condition transmitted

  #define TW_SR_ARB_LOST_GCALL_ACK 0x78
arbitration lost in SLA+RW, general call received, ACK returned

  #define TW_SR_ARB_LOST_SLA_ACK 0x68
arbitration lost in SLA+RW, SLA+W received, ACK returned

  #define TW_SR_DATA_ACK 0x80
data received, ACK returned

  #define TW_SR_DATA_NACK 0x88
data received, NACK returned

  #define TW_SR_GCALL_ACK 0x70
general call received, ACK returned

  #define TW_SR_GCALL_DATA_ACK 0x90
general call data received, ACK returned

  #define TW_SR_GCALL_DATA_NACK 0x98
general call data received, NACK returned

  #define TW_SR_SLA_ACK 0x60
SLA+W received, ACK returned

  #define TW_SR_STOP 0xA0
stop or repeated start condition received while selected

  #define TW_ST_ARB_LOST_SLA_ACK 0xB0
arbitration lost in SLA+RW, SLA+R received, ACK returned

  #define TW_ST_DATA_ACK 0xB8
data transmitted, ACK received

  #define TW_ST_DATA_NACK 0xC0
data transmitted, NACK received

  #define TW_ST_LAST_DATA 0xC8
last data byte transmitted, ACK received

  #define TW_ST_SLA_ACK 0xA8
SLA+R received, ACK returned

  #define TW_START 0x08
start condition transmitted

  #define TW_STATUS (TWSR & TW_STATUS_MASK)
TWSR, masked by TW_STATUS_MASK

  #define TW_STATUS_MASK
Value:

(_BV(TWS7)|_BV(TWS6)|_BV(TWS5)|_BV(TWS4)|\
				_BV(TWS3))
The lower 3 bits of TWSR are reserved on the ATmega163. The 2 LSB carry the prescaler bits on the newer ATmegas.

  #define TW_WRITE 0
SLA+W address

Author

Generated automatically by Doxygen for avr-libc from the source code.