The spi_dma_b2b_transfer_slave example shows how to use driver API to transfer in DMA way. In this example, one spi instance as master and another spi instance on the other board as slave. Master sends a piece of data to slave, and receive a piece of data from slave. This example checksif the data received from master is correct. This example needs to work with spi_dma_b2b_transfer_master example.

The spi_interrupt_b2b_master example shows how to use spi functional API to do interrupt transfer as a master:In this example, the spi instance as master. Master sends a piece of data to slave, receive data from slave,and checkif the data master received is correct. This example needs to work with spi_interrupt_b2b_slave example.

The spi_interrupt_b2b_slave example shows how to use spi functional API to do interrupt transfer as a slave:In this example, the spi instance as slave. Slave receives data froma master and send a peiece of data to master,and check if the data slave received is correct. This example needs to work with spi_interrupt_b2b_master example.

The spi_interrupt_board2board_master example shows how to use spi driver as master to do board to board transfer withinterrupt:In this example, one spi instance as master and another spi instance on othereboard as slave. Master sends a piece ofdata to slave, and receive a piece of data from slave. This example checks if the data received from slave is correct.

The spi_interrupt_board2board_slave example shows how to use spi driver as slave to do board to board transfer with interrupt:In this example, one spi instance as slave and another spi instance on other board as master. Master sends a piece ofdata to slave, and receive a piece of data from slave. This example checks if the data received from master is correct.

The spi_polling_board2board_master example shows how to use spi driver as master to do board to board transfer with polling:In this example, one spi instance as master and another spi instance on othereboard as slave. Master sends a piece ofdata to slave, and receive a piece of data from slave. This example checks if the data received from slave is correct.

The spi_polling_board2board_slave example shows how to use spi driver as slave to do board to board transfer withpolling:Notice: The SPI slave of this example uses interrupt mode, as there is no polling mode for SPI slave.In this example, one spi instance as slave and another spi instance on other board as master. Master sends a piece ofdata to slave, and receive a piece of data from slave. This example checks if the data received from master is correct.

This example shows how to use the DMA driver to implement a double buffer receive scheme from the USARTThe example shows the double buffer constructed using two descriptors (g_pingpong_desc). These descriptors are cycled from one to the other.Things to note- The descriptors of the ping pong transfer need to be aligned to size 16- The inital transfer will perform the same job as first descriptor of ping pong, so the first linkeage is to go to g_pingpong_desc[1]- g_pingpong_desc[1] then chains the g_pingpong_desc[0] as the next descriptor- The properties are set up such that g_pingpong_desc[0] (and the initial configuration uses INTA to signal back to the callback)- g_pingpong_desc[1] uses INTB to signal to the callback- The scheduled callback uses this information to know which data was last writtenA note on PerformanceThe intent of this example is to illustrate how a double-buffer scheme can be implemented using the dma. The performance of this example will be limited to how quickly the echo printer can read-out the data from the ping pong buffer and display it. This means that the example will work well if characters are entered at a rate where the DMA callback to echo the string can keep up with the input stream. Connecting the USARTRX to a continuous fast speed will cause the DMA to fall behind.

The usart_dma example shows how to use usart driver with DMA:In this example, one usart instance connect to PC through usart, the board willsend back all characters that PC send to the board.Note: The example echo every 8 characters, so input 8 characters every time.

The usart_hardware_flow_control example project demonstrates the usage of the hardware flow control function. This example sends data to itself(loopback), and hardware flow control is enabled in the example. The CTS(clear-to-send) pin is for transmiter to check if receiver is ready, if the CTS pin is asserted, transmiter starts to send data. The RTS(request-to-send) pin is for receiver to inform the transmiter if receiver is ready to receive data. So, please connect RTS to CTS pin directly.