TX FIFO Management

Macros
#define	ALT_I2C_TX_FIFO_NUM_ENTRIES   64

Functions
ALT_STATUS_CODE	alt_i2c_tx_fifo_is_empty (ALT_I2C_DEV_t *i2c_dev)
ALT_STATUS_CODE	alt_i2c_tx_fifo_is_full (ALT_I2C_DEV_t *i2c_dev)
ALT_STATUS_CODE	alt_i2c_tx_fifo_level_get (ALT_I2C_DEV_t *i2c_dev, uint32_t *num_entries)
ALT_STATUS_CODE	alt_i2c_tx_fifo_threshold_get (ALT_I2C_DEV_t *i2c_dev, uint8_t *threshold)
ALT_STATUS_CODE	alt_i2c_tx_fifo_threshold_set (ALT_I2C_DEV_t *i2c_dev, const uint8_t threshold)

Detailed Description

The transmit FIFO has a configurable threshold value that controls the level of entries (or below) that sets the TX_EMPTY status condition and triggers an interrupt. The valid range is 0 - (ALT_I2C_TX_FIFO_NUM_ENTRIES-1), with the additional restriction that I2C controller does not allow this value to be set to a value larger than the depth of the buffer. If an attempt is made to do that, the actual value set will be the maximum depth of the buffer. A value of 0 sets the threshold for 0 entries, and a value of (ALT_I2C_TX_FIFO_NUM_ENTRIES-1) sets the threshold for (ALT_I2C_TX_FIFO_NUM_ENTRIES-1) entries.

Macro Definition Documentation

ALT_I2C_TX_FIFO_NUM_ENTRIES

#define ALT_I2C_TX_FIFO_NUM_ENTRIES   64

The number of entries (depth) of the I2C controller transmit FIFO.

Function Documentation

alt_i2c_tx_fifo_is_empty()

ALT_STATUS_CODE alt_i2c_tx_fifo_is_empty

(

ALT_I2C_DEV_t *

i2c_dev

)

Returns ALT_E_TRUE when the transmit FIFO is empty.

Parameters

i2c_dev

A pointer to the I2C controller device block instance.

Return values

ALT_E_SUCCESS	Successful status.
ALT_E_ERROR	Details about error status code

alt_i2c_tx_fifo_is_full()

ALT_STATUS_CODE alt_i2c_tx_fifo_is_full

(

ALT_I2C_DEV_t *

i2c_dev

)

Returns ALT_E_TRUE when the transmit FIFO is completely full.

Parameters

i2c_dev

A pointer to the I2C controller device block instance.

Return values

ALT_E_SUCCESS	Successful status.
ALT_E_ERROR	Details about error status code

alt_i2c_tx_fifo_level_get()

ALT_STATUS_CODE alt_i2c_tx_fifo_level_get	(	ALT_I2C_DEV_t *	i2c_dev,
		uint32_t *	num_entries
	)

Returns the number of valid entries in the transmit FIFO.

Parameters

i2c_dev	A pointer to the I2C controller device block instance.
num_entries	[out] The number of entries in the transmit FIFO.

Return values

ALT_E_SUCCESS	Successful status.
ALT_E_ERROR	Details about error status code

alt_i2c_tx_fifo_threshold_get()

ALT_STATUS_CODE alt_i2c_tx_fifo_threshold_get	(	ALT_I2C_DEV_t *	i2c_dev,
		uint8_t *	threshold
	)

Gets the current transmit FIFO threshold level value.

Parameters

i2c_dev	A pointer to the I2C controller device block instance.
threshold	[out] The current threshold value.

Return values

ALT_E_SUCCESS	Successful status.
ALT_E_ERROR	Details about error status code

alt_i2c_tx_fifo_threshold_set()

ALT_STATUS_CODE alt_i2c_tx_fifo_threshold_set	(	ALT_I2C_DEV_t *	i2c_dev,
		const uint8_t	threshold
	)

Sets the current transmit FIFO threshold level value.

Parameters

i2c_dev	A pointer to the I2C controller device block instance.
threshold	The threshold value.

Return values

ALT_E_SUCCESS	Successful status.
ALT_E_ERROR	Details about error status code