SPI 2SPI DMA Write Read

This document introduces two SPI communication samples. The sample1 demonstrates how SPI0 reads data and SPI1 sends data by GDMA. The sample2 demonstrates how SPI0 reads data and SPI1 sends data by auto-reload GDMA. In both examples, SPI is configured as a master, and operates in GDMA mode. The direction of SPI0 is EEPROM read, the direction of SPI1 is TX only. The chip reads data from the SPI slave device0 and writes data to the SPI slave device1.

Requirements

For hardware requirements, please refer to the Requirements.

Wiring

Connect P1_7 to CS of SPI slave device 0, connect P1_4 to SCK of SPI slave device 0, connect P1_5 to MISO of SPI slave device 0, and connect P1_6 to MOSI of SPI slave device 0. Connect P2_5 to CS of SPI slave device 1, connect P2_2 to SCK of SPI slave device 1, connect P2_3 to MISO of SPI slave device 1, and connect P2_4 to MOSI of SPI slave device 1. The hardware connection of SPI sample code is shown in the figure below.

SPI Sample Code Hardware Connection Diagram

Configurations

1. The following macros can be configured to modify pin definitions.

   • #define PIN_SPI0_SCK P1_4

   • #define PIN_SPI0_MOSI P1_5

   • #define PIN_SPI0_MISO P1_6

   • #define PIN_SPI0_CS P1_7

   • #define PIN_SPI1_SCK P2_2

   • #define PIN_SPI1_MOSI P2_3

   • #define PIN_SPI1_MISO P2_4

   • #define PIN_SPI1_CS P2_5

2. The entry function are as follows, call this function in main() to run this sample code. For more details, please refer to the Initialization.

   For sample 1, use the following entry function:

   spi2spi_dma_demo();
   

   For sample 2, use the following entry function:

   spi2spi_auto_reload_dma_demo();
   

Building and Downloading

For building and downloading, please refer to the Building and Downloading.

Experimental Verification

Sample Verification

1. Press the Reset button on the EVB.

2. SPI0 reads data from SPI slave device 0 and SPI1 sends the same data to SPI slave device 1.

Code Overview

Source Code Directory

For both samples, please refer to the Source Code Directory for the project directory.

Sample 1 source code:

• Source code directory: sdk\src\sample\io_demo\spi\spi2spi_dma\spi2spi_dma_demo.c .

Sample 2 source code:

• Source code directory: sdk\src\sample\io_demo\spi\spi2spi_auto_reload_dma\spi2spi_auto_reload_dma_demo.c .

2SPI Initialization Flow

The initialization flow for peripherals can refer to Initialization Flow.

The SPI initialization flow can refer to SPI Initialization Flow Chart.

1. Call Pad_Config() and Pinmux_Config() to initialize the SPI0 and SPI1 pins.

   static void board_spi_init(void)
   {
      Pinmux_Config(PIN_SPI0_SCK,  SPI0_CLK_MASTER);
      Pinmux_Config(PIN_SPI0_MOSI, SPI0_MO_MASTER);
      Pinmux_Config(PIN_SPI0_MISO, SPI0_MI_MASTER);
      Pinmux_Config(PIN_SPI0_CS,   SPI0_SS_N_0_MASTER);
   
      Pinmux_Config(PIN_SPI1_SCK,  SPI1_CLK_MASTER);
      Pinmux_Config(PIN_SPI1_MOSI, SPI1_MO_MASTER);
      Pinmux_Config(PIN_SPI1_MISO, SPI1_MI_MASTER);
      Pinmux_Config(PIN_SPI1_CS,   SPI1_SS_N_0_MASTER);
   
      Pad_Config(PIN_SPI0_SCK,  PAD_PINMUX_MODE, PAD_IS_PWRON, PAD_PULL_NONE, PAD_OUT_DISABLE,
                  PAD_OUT_HIGH);
      Pad_Config(PIN_SPI0_MOSI, PAD_PINMUX_MODE, PAD_IS_PWRON, PAD_PULL_NONE, PAD_OUT_DISABLE,
                  PAD_OUT_HIGH);
      Pad_Config(PIN_SPI0_MISO, PAD_PINMUX_MODE, PAD_IS_PWRON, PAD_PULL_NONE, PAD_OUT_DISABLE,
                  PAD_OUT_HIGH);
      Pad_Config(PIN_SPI0_CS,   PAD_PINMUX_MODE, PAD_IS_PWRON, PAD_PULL_NONE, PAD_OUT_DISABLE,
                  PAD_OUT_HIGH);
   
      Pad_Config(PIN_SPI1_SCK,  PAD_PINMUX_MODE, PAD_IS_PWRON, PAD_PULL_NONE, PAD_OUT_DISABLE,
                  PAD_OUT_HIGH);
      Pad_Config(PIN_SPI1_MOSI, PAD_PINMUX_MODE, PAD_IS_PWRON, PAD_PULL_NONE, PAD_OUT_DISABLE,
                  PAD_OUT_HIGH);
      Pad_Config(PIN_SPI1_MISO, PAD_PINMUX_MODE, PAD_IS_PWRON, PAD_PULL_NONE, PAD_OUT_DISABLE,
                  PAD_OUT_HIGH);
      Pad_Config(PIN_SPI1_CS,   PAD_PINMUX_MODE, PAD_IS_PWRON, PAD_PULL_NONE, PAD_OUT_DISABLE,
                  PAD_OUT_HIGH);
   }
   

2. Call RCC_PeriphClockCmd() to enable the SPI0 and SPI1 clock and function.

3. Define the SPI_InitTypeDef type SPI_InitStructure, and call SPI_StructInit() to pre-fill SPI_InitStructure with default values.

4. Initialize the SPI0 peripheral:

   1. Modify the SPI_InitStructure parameters as needed. The SPI initialization parameter configuration is shown in the table below.

   2. Call SPI_Init() to initialize the SPI peripheral.

   3. Call SPI_Cmd() to enable SPI0.

   SPI Initialization Parameters

   SPI Hardware Parameters	Setting in the SPI_InitStructure	SPI
   Direction	SPI_InitTypeDef::SPI_Direction	SPI_Direction_EEPROM
   Device Role (SPI Master or SPI Slave)	SPI_InitTypeDef::SPI_Mode	SPI_Mode_Master
   Data Frame Size	SPI_InitTypeDef::SPI_DataSize	SPI_DataSize_8b
   Clock Polarity	SPI_InitTypeDef::SPI_CPOL	SPI_CPOL_High
   Clock Phase	SPI_InitTypeDef::SPI_CPHA	SPI_CPHA_2Edge
   Clock Div	SPI_InitTypeDef::SPI_BaudRatePrescaler	100
   Frame Format	SPI_InitTypeDef::SPI_FrameFormat	SPI_Frame_Motorola
   RX Number of Data Frames	SPI_InitTypeDef::SPI_NDF	255
   RX DMA Enable	SPI_InitTypeDef::SPI_RxDmaEn	ENABLE
   RX Water Level	SPI_InitTypeDef::SPI_RxWaterlevel	8

5. Initialize the SPI1 peripheral:

   1. Modify the SPI_InitStructure parameters as needed. The SPI initialization parameter configuration is shown in the table below.

   2. Call SPI_Init() to initialize the SPI peripheral.

   3. Call SPI_Cmd() to enable SPI1.

   SPI Initialization Parameters

   SPI Hardware Parameters	Setting in the SPI_InitStructure	SPI
   Direction	SPI_InitTypeDef::SPI_Direction	SPI_Direction_TxOnly
   Device Role (SPI Master or SPI Slave)	SPI_InitTypeDef::SPI_Mode	SPI_Mode_Master
   Data Frame Size	SPI_InitTypeDef::SPI_DataSize	SPI_DataSize_8b
   Clock Polarity	SPI_InitTypeDef::SPI_CPOL	SPI_CPOL_High
   Clock Phase	SPI_InitTypeDef::SPI_CPHA	SPI_CPHA_2Edge
   Frame Format	SPI_InitTypeDef::SPI_FrameFormat	SPI_Frame_Motorola
   RX DMA Enable	SPI_InitTypeDef::SPI_TxDmaEn	ENABLE
   RX Water Level	SPI_InitTypeDef::SPI_TxWaterlevel	35

2SPI DMA Initialization Flow

The initialization flow for peripherals can refer to Initialization Flow.

1. Call RCC_PeriphClockCmd() to enable the GDMA clock and function.

2. Call GDMA_channel_request to request a free GDMA channel and register the GDMA interrupt handler.

3. Initialize the GDMA peripheral:

   1. Define the GDMA_InitTypeDef type GDMA_InitStruct, and call GDMA_StructInit() to pre-fill GDMA_InitStruct with default values.

   2. Modify the GDMA_InitStruct parameters as needed. The GDMA initialization parameter configuration is shown in the table below.

   3. Call GDMA_Init() to initialize the GDMA peripheral.

   GDMA Initialization Parameters

   GDMA Hardware Parameters	Setting in the GDMA_InitStruct	GDMA
   Channel Num	GDMA_InitTypeDef::GDMA_ChannelNum	SPI2SPI_DMA_CHANNEL_NUM
   Transfer Direction	GDMA_InitTypeDef::GDMA_DIR	GDMA_DIR_PeripheralToPeripheral
   Buffer Size	GDMA_InitTypeDef::GDMA_BufferSize	256
   Source Address Increment or Decrement	GDMA_InitTypeDef::GDMA_SourceInc	DMA_SourceInc_Fix
   Destination Address Increment or Decrement	GDMA_InitTypeDef::GDMA_DestinationInc	DMA_DestinationInc_Fix
   Source Data Size	GDMA_InitTypeDef::GDMA_SourceDataSize	GDMA_DataSize_Byte
   Destination Data Size	GDMA_InitTypeDef::GDMA_DestinationDataSize	GDMA_DataSize_Byte
   Source Burst Transaction Length	GDMA_InitTypeDef::GDMA_SourceMsize	GDMA_Msize_1
   Destination Burst Transaction Length	GDMA_InitTypeDef::GDMA_DestinationMsize	GDMA_Msize_1
   Source Address	GDMA_InitTypeDef::GDMA_SourceAddr	SPI0->DR
   Destination Address	GDMA_InitTypeDef::GDMA_DestinationAddr	SPI1->DR
   Source Handshake	GDMA_InitTypeDef::GDMA_SourceHandshake	GDMA_Handshake_SPI0_RX
   Destination Handshake	GDMA_InitTypeDef::GDMA_DestHandshake	GDMA_Handshake_SPI1_TX

4. Call GDMA_INTConfig() to enable GDMA transfer complete interrupt GDMA_INT_Transfer.

5. Call NVIC_Init() to enable NVIC of GDMA.

2SPI Auto-Reload DMA Initialization Flow

The initialization flow for peripherals can refer to Initialization Flow.

1. Call RCC_PeriphClockCmd() to enable the GDMA clock and function.

2. Call GDMA_channel_request to request a free GDMA channel and register the GDMA interrupt handler.

3. Initialize the GDMA peripheral:

   1. Define the GDMA_InitTypeDef type GDMA_InitStruct, and call GDMA_StructInit() to pre-fill GDMA_InitStruct with default values.

   2. Modify the GDMA_InitStruct parameters as needed. The GDMA initialization parameter configuration is shown in the table below.

   3. Call GDMA_Init() to initialize the GDMA peripheral.

   GDMA Initialization Parameters

   GDMA Hardware Parameters	Setting in the GDMA_InitStruct	GDMA
   Channel Num	GDMA_InitTypeDef::GDMA_ChannelNum	SPI_AUTO_RELOAD_DMA_CHANNEL_NUM
   Transfer Direction	GDMA_InitTypeDef::GDMA_DIR	GDMA_DIR_PeripheralToPeripheral
   Buffer Size	GDMA_InitTypeDef::GDMA_BufferSize	256
   Source Address Increment or Decrement	GDMA_InitTypeDef::GDMA_SourceInc	DMA_SourceInc_Fix
   Destination Address Increment or Decrement	GDMA_InitTypeDef::GDMA_DestinationInc	DMA_DestinationInc_Fix
   Source Data Size	GDMA_InitTypeDef::GDMA_SourceDataSize	GDMA_DataSize_Byte
   Destination Data Size	GDMA_InitTypeDef::GDMA_DestinationDataSize	GDMA_DataSize_Byte
   Source Burst Transaction Length	GDMA_InitTypeDef::GDMA_SourceMsize	GDMA_Msize_1
   Destination Burst Transaction Length	GDMA_InitTypeDef::GDMA_DestinationMsize	GDMA_Msize_1
   Source Address	GDMA_InitTypeDef::GDMA_SourceAddr	SPI0->DR
   Destination Address	GDMA_InitTypeDef::GDMA_DestinationAddr	SPI1->DR
   Source Handshake	GDMA_InitTypeDef::GDMA_SourceHandshake	GDMA_Handshake_SPI0_RX
   Destination Handshake	GDMA_InitTypeDef::GDMA_DestHandshake	GDMA_Handshake_SPI1_TX
   Multi Block Enable	GDMA_InitTypeDef::GDMA_Multi_Block_En	ENABLE
   Multi Block Mode	GDMA_InitTypeDef::GDMA_Multi_Block_Mode	AUTO_RELOAD_TRANSFER

Functional Implementation

2SPI DMA Interupt Handle

When GDMA transfer is completed, transfer complete interrupt is triggered.

1. Call GDMA_ClearAllTypeINT() to clear the all GDMA channel interrupt.

2. Call GDMA_channel_release() to release the used GDMA channel.