【N32G430C8L7开发板体验】+SPI外设通讯速度测试
根据用户手册，SPI接口的最高速度，在主模式下可以达到28 Mbps（不带CRC），20Mbps(带CRC)，从模式可以达到32Mbps。
按照这个说明，启动SPI的通讯例程，选择的是SPI_INT例程，为了能顺利捕捉波形，稍微修改了代码，是SPI的收发处理一直被循环。
Main处理被修改为：
- int main(void)
- {
- /* At this stage the microcontroller clock setting is already configured,
- this is done through SystemInit() function which is called from startup
- file (startup_N32G430.s) before to branch to application main.
- To reconfigure the default setting of SystemInit() function, refer to
- system_N32G430.c file
- */
- /* System clocks configuration ---------------------------------------------*/
- RCC_Configuration();
- /* GPIO configuration ------------------------------------------------------*/
- GPIO_Configuration();
-
- NVIC_Configuration();
- /* log configuration ------------------------------------------------------*/
- log_init();
- log_info("This is SPI INT demo!\r\n");
- /* SPI_MASTER configuration ------------------------------------------------------*/
- SPI_Initializes_Structure(&SPI_InitStructure);
- SPI_InitStructure.DataDirection = SPI_DIR_SINGLELINE_TX;
- SPI_InitStructure.SpiMode = SPI_MODE_MASTER;
- SPI_InitStructure.DataLen = SPI_DATA_SIZE_16BITS;
- SPI_InitStructure.CLKPOL = SPI_CLKPOL_LOW;
- SPI_InitStructure.CLKPHA = SPI_CLKPHA_SECOND_EDGE;
- SPI_InitStructure.NSS = SPI_NSS_HARD;
- /* It is recommended that the SPI master mode of the C version chips should not exceed 18MHz */
- SPI_InitStructure.BaudRatePres = SPI_BR_PRESCALER_8;
- SPI_InitStructure.FirstBit = SPI_FB_MSB;
- SPI_InitStructure.CRCPoly = 7;
- SPI_Initializes(SPI_MASTER, &SPI_InitStructure);
- SPI_SS_Output_Enable(SPI_MASTER);
- /* SPI_SLAVE configuration ------------------------------------------------------*/
- SPI_InitStructure.SpiMode = SPI_MODE_SLAVE;
- SPI_InitStructure.DataDirection = SPI_DIR_SINGLELINE_RX;
- SPI_Initializes(SPI_SLAVE, &SPI_InitStructure);
- /* Enable the master and slave SPI interrupts ----------------------------------*/
- SPI_I2S_Interrupts_Enable(SPI_MASTER, SPI_I2S_INT_TE);
- SPI_I2S_Interrupts_Enable(SPI_SLAVE, SPI_I2S_INT_RNE);
- /* Enable SPI_SLAVE */
- SPI_ON(SPI_SLAVE);
- /* Enable SPI_MASTER */
- SPI_ON(SPI_MASTER);
- /* Transfer procedure */
- while (RxIdx < BufferSize);
-
- /* Check the received data with the send ones */
- TransferStatus = Buffercmp(SPI_Slave_Buffer_Rx, SPI_Master_Buffer_Tx, BufferSize);
- if(TransferStatus == PASSED) {
- log_info("Test PASS!\r\n");
- } else {
- log_info("Test ERR!\r\n");
- }
- TxIdx = 0;
- RxIdx = 0;
- SPI_I2S_Data_Transmit(SPI1, SPI_Master_Buffer_Tx[0]);
-
- while(1) {
- /* Transfer procedure */
- while (RxIdx < 1);
- // 为了测试发送速度，不断重复发送
- TxIdx = 0;
- RxIdx = 0;
- SPI_I2S_Data_Transmit(SPI1, SPI_Master_Buffer_Tx[0]);
- }
- }
中断处理被改为：
- /**
- *\*\name SPI1_IRQHandler.
- *\*\fun This function handles SPI1 Handler.
- *\*\param none
- *\*\return none
- **/
- void SPI1_IRQHandler(void) {
- if(SPI_I2S_Interrupt_Flag_Status_Get(SPI1, SPI_I2S_INT_FLAG_TE) != RESET) {
- /* Send SPI_MASTER data */
- SPI_I2S_Data_Transmit(SPI1, SPI_Master_Buffer_Tx[TxIdx++]);
- if(TxIdx == BufferSize) {
- /* Disable SPI_MATER TXE interrupt */
- //SPI_I2S_Interrupts_Disable(SPI1, SPI_I2S_INT_TE);
- }
- }
- }
- /**
- *\*\name SPI2_IRQHandler.
- *\*\fun This function handles SPI2 Handler.
- *\*\param none
- *\*\return none
- **/
- void SPI2_IRQHandler(void) {
- if(SPI_I2S_Interrupt_Flag_Status_Get(SPI2, SPI_I2S_INT_FLAG_RNE) == SET) {
- /* Store SPI_SLAVE received data */
- SPI_Slave_Buffer_Rx[RxIdx++] = SPI_I2S_Data_Get(SPI2);
- }
- }
然后测试，捕捉的通讯SCK脉冲波形如下：
波形不是方波，时钟周期是120ns的样子，确实比用GPIO模拟的方式快啊，差别很明显。
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