twi_at91.h File Reference

Driver for the AT91 ARM TWI (implementation). More...

#include <cfg/compiler.h>

Go to the source code of this file.

Functions
void	twi_init (void)
	Init the (broken) sam7 twi driver.
bool	twi_read (uint8_t id, twi_iaddr_t byte1, twi_iaddr_t byte2, twi_iaddr_t byte3, void *_buf, size_t len)
	Read size bytes from the twi line from slave id.
bool	twi_write (uint8_t id, twi_iaddr_t byte1, twi_iaddr_t byte2, twi_iaddr_t byte3, const void *_buf, size_t len)
	Send size bytes over the twi line to slave id.

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Detailed Description

Driver for the AT91 ARM TWI (implementation).

Version:

Id

twi_at91.h 1221 2008-04-09 14:38:11Z batt

Author:

Francesco Sacchi <batt@develer.com>

Definition in file twi_at91.h.

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Function Documentation

bool twi_read	(	uint8_t	id,
		twi_iaddr_t	byte1,
		twi_iaddr_t	byte2,
		twi_iaddr_t	byte3,
		void *	_buf,
		size_t	size
	)

Read size bytes from the twi line from slave id.

If the device requires internal addressing before reading, byte1 byte2 and byte3 must be specified. Internal addressign bytes not used *must* be set to TWI_NO_IADDR. If 1 or 2 bytes are required for internal addressing you *must* first use byte1 and than byte2.

Note:

Atmel TWI implementation is broken so it was not possible to supply a better interface. Additionally NACK handling is also broken, so if the i2c device reply nack this function will return after TWI_TIMEOUT.

Returns:

true if ok, false on slave timeout.

Definition at line 140 of file twi_at91.c.

bool twi_write	(	uint8_t	id,
		twi_iaddr_t	byte1,
		twi_iaddr_t	byte2,
		twi_iaddr_t	byte3,
		const void *	_buf,
		size_t	size
	)

Send size bytes over the twi line to slave id.

If the device requires internal addressing before writing, byte1 byte2 and byte3 can be specified. Internal addressign bytes not used *must* be set to TWI_NO_IADDR. If 1 or 2 bytes are required for internal addressing you *must* first use byte1 and than byte2.

Note:

Atmel TWI implementation is broken so it was not possible to supply a better interface. Additionally NACK handling is also broken, so if the i2c device reply nack this function will return after TWI_TIMEOUT.

Returns:

true if ok, false on slave timeout.

Definition at line 66 of file twi_at91.c.