Altera HWLIB  16.0
The Altera HW Manager API Reference Manual
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RX FIFO Management

Description

The receive FIFO has a configurable threshold value that controls the level of entries (or above) that sets the RX_FULL status condition and triggers an interrupt. The valid range is 0..(ALT_SPI_RX_FIFO_NUM_ENTRIES - 1), with the additional restriction that SPI 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 1 entry, and a value of (ALT_SPI_RX_FIFO_NUM_ENTRIES - 1) sets the threshold for ALT_SPI_RX_FIFO_NUM_ENTRIES entries.

Macros

#define ALT_SPI_RX_FIFO_NUM_ENTRIES   256
 

Functions

ALT_STATUS_CODE alt_spi_rx_fifo_deq (ALT_SPI_DEV_t *spi_dev, uint16_t *data)
 
ALT_STATUS_CODE alt_spi_rx_fifo_is_empty (ALT_SPI_DEV_t *spi_dev)
 
ALT_STATUS_CODE alt_spi_rx_fifo_is_full (ALT_SPI_DEV_t *spi_dev)
 
ALT_STATUS_CODE alt_spi_rx_fifo_level_get (ALT_SPI_DEV_t *spi_dev, uint32_t *num_entries)
 
ALT_STATUS_CODE alt_spi_rx_fifo_threshold_get (ALT_SPI_DEV_t *spi_dev, uint8_t *threshold)
 
ALT_STATUS_CODE alt_spi_rx_fifo_threshold_set (ALT_SPI_DEV_t *spi_dev, const uint8_t threshold)
 

Macro Definitions

#define ALT_SPI_RX_FIFO_NUM_ENTRIES   256

The number of entries (depth) of the SPI controller receive FIFO.

Function Documentation

ALT_STATUS_CODE alt_spi_rx_fifo_deq ( ALT_SPI_DEV_t *  spi_dev,
uint16_t *  data 
)

Reads a data frame from the receive (Rx) FIFO.

Parameters
spi_devA pointer to the SPI controller device block instance.
data[out] The data frame read from into the Rx FIFO. The data parameter type is sized large enough to contain the widest possible data frame size.
Return values
ALT_E_SUCCESSSuccessful status.
ALT_E_ERRORDetails about error status code
ALT_STATUS_CODE alt_spi_rx_fifo_is_empty ( ALT_SPI_DEV_t *  spi_dev)

Returns ALT_E_TRUE when the receive FIFO is empty.

Parameters
spi_devA pointer to the SPI controller device block instance.
Return values
ALT_E_SUCCESSSuccessful status.
ALT_E_ERRORDetails about error status code
ALT_STATUS_CODE alt_spi_rx_fifo_is_full ( ALT_SPI_DEV_t *  spi_dev)

Returns ALT_E_TRUE when the receive FIFO is completely full.

Parameters
spi_devA pointer to the SPI controller device block instance.
Return values
ALT_E_SUCCESSSuccessful status.
ALT_E_ERRORDetails about error status code
ALT_STATUS_CODE alt_spi_rx_fifo_level_get ( ALT_SPI_DEV_t *  spi_dev,
uint32_t *  num_entries 
)

Returns the number of valid entries in the receive FIFO.

Parameters
spi_devA pointer to the SPI controller device block instance.
num_entries[out] The number of entries in the receive FIFO.
Return values
ALT_E_SUCCESSSuccessful status.
ALT_E_ERRORDetails about error status code
ALT_STATUS_CODE alt_spi_rx_fifo_threshold_get ( ALT_SPI_DEV_t *  spi_dev,
uint8_t *  threshold 
)

Gets the current receive FIFO threshold level value.

Parameters
spi_devA pointer to the SPI controller device block instance.
threshold[out] The current threshold value.
Return values
ALT_E_SUCCESSSuccessful status.
ALT_E_ERRORDetails about error status code
ALT_STATUS_CODE alt_spi_rx_fifo_threshold_set ( ALT_SPI_DEV_t *  spi_dev,
const uint8_t  threshold 
)

Sets the current receive FIFO threshold level value.

Parameters
spi_devA pointer to the SPI controller device block instance.
thresholdThe threshold value.
Return values
ALT_E_SUCCESSSuccessful status.
ALT_E_ERRORDetails about error status code