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spi_slave

内部関数です。通常は使いません。

利用方法

#include <driver/spi_slave.h>

上記宣言で利用できます。

メンバー

spi_slave_initialize()

Initialize a SPI bus as a slave interface

esp_err_t spi_slave_initialize(spi_host_device_t host, const spi_bus_config_t *bus_config, const spi_slave_interface_config_t *slave_config, int dma_chan)

引数

  • spi_host_device_t host SPI peripheral to use as a SPI slave interface
  • spi_bus_config_tconst * bus_config Pointer to a struct specifying how the host should be initialized
  • spi_slave_interface_config_tconst * slave_config Pointer to a struct specifying the details for the slave interface
  • int dma_chan Either 1 or 2. A SPI bus used by this driver must have a DMA channel associated with it. The SPI hardware has two DMA channels to share. This parameter indicates which one to use.

戻り値

esp_err_t

spi_slave_free()

Free a SPI bus claimed as a SPI slave interface

esp_err_t spi_slave_free(spi_host_device_t host)

引数

  • spi_host_device_t host SPI peripheral to free

戻り値

esp_err_t

spi_slave_queue_trans()

Queue a SPI transaction for execution

This function hands over ownership of the buffers in to the SPI slave driver; the application is not to access this memory until is called to hand ownership back to the application. 

esp_err_t spi_slave_queue_trans(spi_host_device_t host, const spi_slave_transaction_t *trans_desc, TickType_t ticks_to_wait)

引数

  • spi_host_device_t host SPI peripheral that is acting as a slave
  • spi_slave_transaction_tconst * trans_desc Description of transaction to execute. Not const because we may want to write status back into the transaction description.
  • TickType_t ticks_to_wait Ticks to wait until there's room in the queue; use portMAX_DELAY to never time out.

戻り値

esp_err_t

spi_slave_get_trans_result()

Get the result of a SPI transaction queued earlier

It is mandatory to eventually use this function for any transaction queued by . 

esp_err_t spi_slave_get_trans_result(spi_host_device_t host, spi_slave_transaction_t **trans_desc, TickType_t ticks_to_wait)

引数

  • spi_host_device_t host SPI peripheral to that is acting as a slave
  • spi_slave_transaction_t** trans_desc Pointer to variable able to contain a pointer to the description of the transaction that is executed
  • TickType_t ticks_to_wait Ticks to wait until there's a returned item; use portMAX_DELAY to never time out.

戻り値

esp_err_t

spi_slave_transmit()

Do a SPI transaction

Essentially does the same as spi_slave_queue_trans followed by spi_slave_get_trans_result. Do not use this when there is still a transaction queued that hasn't been finalized using spi_slave_get_trans_result. 

esp_err_t spi_slave_transmit(spi_host_device_t host, spi_slave_transaction_t *trans_desc, TickType_t ticks_to_wait)

引数

  • spi_host_device_t host SPI peripheral to that is acting as a slave
  • spi_slave_transaction_t* trans_desc Pointer to variable able to contain a pointer to the description of the transaction that is executed. Not const because we may want to write status back into the transaction description.
  • TickType_t ticks_to_wait Ticks to wait until there's a returned item; use portMAX_DELAY to never time out.

戻り値

esp_err_t