Workflow

system_init();

configure_spi_master();

1. 2.1.
   Create configuration struct.

   struct spi_config config_spi_master;
   

2. 2.2.
   Create peripheral slave configuration struct.

   struct spi_slave_inst_config slave_dev_config;
   

3. 2.3.
   Get default peripheral slave configuration.

   spi_slave_inst_get_config_defaults(&slave_dev_config);
   

4. 2.4.
   Set Slave Select pin.

   slave_dev_config.ss_pin = SLAVE_SELECT_PIN;
   

5. 2.5.
   Initialize peripheral slave software instance with configuration.

   spi_attach_slave(&slave, &slave_dev_config);
   

6. 2.6.
   Get default configuration to edit.

   spi_get_config_defaults(&config_spi_master);
   

7. 2.7.
   Set MUX setting E.

   config_spi_master.mux_setting = EXT1_SPI_SERCOM_MUX_SETTING;
   

8. 2.8.
   Set pinmux for pad 0 (data in MISO).

   config_spi_master.pinmux_pad0 = EXT1_SPI_SERCOM_PINMUX_PAD0;
   

9. 2.9.
   Set pinmux for pad 1 as unused, so the pin can be used for other purposes.

   config_spi_master.pinmux_pad1 = PINMUX_UNUSED;
   

10. 2.10.
    Set pinmux for pad 2 (data out MOSI).

    config_spi_master.pinmux_pad2 = EXT1_SPI_SERCOM_PINMUX_PAD2;
    

11. 2.11.
    Set pinmux for pad 3 (SCK).

    config_spi_master.pinmux_pad3 = EXT1_SPI_SERCOM_PINMUX_PAD3;
    

12. 2.12.
    Initialize SPI module with configuration.

    spi_init(&spi_master_instance, EXT1_SPI_MODULE, &config_spi_master);
    

13. 2.13.
    Enable SPI module.

    spi_enable(&spi_master_instance);
    

configure_spi_master_callbacks();

1. 3.1.
   Register callback function for buffer transmitted.

   spi_register_callback(&spi_master_instance, callback_spi_master,
           SPI_CALLBACK_BUFFER_TRANSCEIVED);
   

2. 3.2.
   Enable callback for buffer transmitted.

   spi_enable_callback(&spi_master_instance, SPI_CALLBACK_BUFFER_TRANSCEIVED);