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_SPI_TX_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 0 entries, and a value of (ALT_SPI_TX_FIFO_NUM_ENTRIES - 1) sets the threshold for (ALT_SPI_TX_FIFO_NUM_ENTRIES - 1) entries.
#define ALT_SPI_TX_FIFO_NUM_ENTRIES 256 |
The number of entries (depth) of the SPI controller transmit FIFO.
ALT_STATUS_CODE alt_spi_tx_fifo_enq |
( |
ALT_SPI_DEV_t * |
spi_dev, |
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const uint16_t |
data |
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) |
| |
Writes a data frame to the transmit (Tx) FIFO for transmittal.
- Parameters
-
spi_dev | A pointer to the SPI controller device block instance. |
data | The data frame to put into the Tx FIFO. The data parameter type is sized large enough to contain the widest possible data frame size. The data in each frame should be right justified within the data parameter. |
- Return values
-
ALT_E_SUCCESS | Successful status. |
ALT_E_ERROR | Details about error status code |
ALT_STATUS_CODE alt_spi_tx_fifo_is_empty |
( |
ALT_SPI_DEV_t * |
spi_dev | ) |
|
Returns ALT_E_TRUE when the transmit FIFO is empty.
- Parameters
-
spi_dev | A pointer to the SPI controller device block instance. |
- Return values
-
ALT_E_SUCCESS | Successful status. |
ALT_E_ERROR | Details about error status code |
ALT_STATUS_CODE alt_spi_tx_fifo_is_full |
( |
ALT_SPI_DEV_t * |
spi_dev | ) |
|
Returns ALT_E_TRUE when the transmit FIFO is completely full.
- Parameters
-
spi_dev | A pointer to the SPI controller device block instance. |
- Return values
-
ALT_E_SUCCESS | Successful status. |
ALT_E_ERROR | Details about error status code |
ALT_STATUS_CODE alt_spi_tx_fifo_level_get |
( |
ALT_SPI_DEV_t * |
spi_dev, |
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uint32_t * |
num_entries |
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) |
| |
Returns the number of valid entries in the transmit FIFO.
- Parameters
-
spi_dev | A pointer to the SPI 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_STATUS_CODE alt_spi_tx_fifo_threshold_get |
( |
ALT_SPI_DEV_t * |
spi_dev, |
|
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uint8_t * |
threshold |
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) |
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Gets the current transmit FIFO threshold level value.
- Parameters
-
spi_dev | A pointer to the SPI 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_STATUS_CODE alt_spi_tx_fifo_threshold_set |
( |
ALT_SPI_DEV_t * |
spi_dev, |
|
|
const uint8_t |
threshold |
|
) |
| |
Sets the current transmit FIFO threshold level value.
- Parameters
-
spi_dev | A pointer to the SPI controller device block instance. |
threshold | The threshold value. |
- Return values
-
ALT_E_SUCCESS | Successful status. |
ALT_E_ERROR | Details about error status code |