芯片： SMT32F103RET6。
        问题： 在使用SPI 做从机时，接收发送都是DMA模式。 在发送时， DMA偶尔会跳过发送缓存的第2个字节， 调试了好几天， 没有头绪，望大家帮忙看看，
       
        代码:
                1. SPI 初始化

       

1. 
   
2. //
   
3. //       SPI PART
   
4. static void m_spi_init(void) {
   
5.     GPIO_InitTypeDef GPIO_InitStructure;
   
6.     SPI_InitTypeDef  SPI_InitStructure;
   
7.     NVIC_InitTypeDef NVIC_InitStructure;
   
8.     DMA_InitTypeDef  DMA_InitStructure;
   
9.     EXTI_InitTypeDef EXTI_InitStructure;
   
10. 
    
11.     // enable clocks
    
12.     RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE);
    
13.     RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE);
    
14. 
    
15.     // MISO
    
16.     GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_14;
    
17.     GPIO_InitStructure.GPIO_Mode =  GPIO_Mode_AF_PP;
    
18.     GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    
19.     GPIO_Init(GPIOB, &GPIO_InitStructure);
    
20. 
    
21.     // sck  mosi nss
    
22.     GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15 | GPIO_Pin_13 | GPIO_Pin_12;
    
23.     GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    
24.     GPIO_Init(GPIOB, &GPIO_InitStructure);
    
25.    
    
26.     // enable cs  interrupt
    
27.     GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource12);
    
28. 
    
29.     EXTI_InitStructure.EXTI_Line    = EXTI_Line12;
    
30.     EXTI_InitStructure.EXTI_Mode    = EXTI_Mode_Interrupt;
    
31.     EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
    
32.     EXTI_InitStructure.EXTI_LineCmd = ENABLE;
    
33.     EXTI_Init(&EXTI_InitStructure);
    
34. 
    
35.    
    
36.     NVIC_InitStructure.NVIC_IRQChannel                   = EXTI15_10_IRQn; //使能外部中断所在的通道
    
37.     NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00; //抢占优先级 2，
    
38.     NVIC_InitStructure.NVIC_IRQChannelSubPriority        = 0x01; //子优先级 2
    
39.     NVIC_InitStructure.NVIC_IRQChannelCmd                = ENABLE; //使能外部中断通道
    
40.     NVIC_Init(&NVIC_InitStructure);
    
41.    
    
42. #if 1
    
43.     RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
    
44. 
    
45.     DMA_DeInit(DMA1_Channel4); //Set DMA registers to default values
    
46.     DMA_StructInit(&DMA_InitStructure);
    
47. 
    
48.     DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&SPI2->DR; //Address of peripheral the DMA must map to
    
49.     DMA_InitStructure.DMA_MemoryBaseAddr     = (uint32_t)m_spi_dma_receive_buff; //Variable to which received data will be stored
    
50.     DMA_InitStructure.DMA_DIR                = DMA_DIR_PeripheralSRC;
    
51.     DMA_InitStructure.DMA_BufferSize         = sizeof(m_spi_dma_receive_buff); //Buffer size
    
52.     DMA_InitStructure.DMA_PeripheralInc      = DMA_PeripheralInc_Disable;
    
53.     DMA_InitStructure.DMA_MemoryInc          = DMA_MemoryInc_Enable;
    
54.     DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
    
55.     DMA_InitStructure.DMA_MemoryDataSize     = DMA_PeripheralDataSize_Byte;
    
56.     DMA_InitStructure.DMA_Mode               = DMA_Mode_Circular;
    
57.     DMA_InitStructure.DMA_Priority           = DMA_Priority_High;
    
58.     DMA_InitStructure.DMA_M2M                = DMA_M2M_Disable;
    
59.     DMA_Init(DMA1_Channel4, &DMA_InitStructure); //Initialise the DMAa
    
60. 
    
61.     DMA_DeInit(DMA1_Channel5);               
    
62.     DMA_StructInit(&DMA_InitStructure);
    
63. 
    
64.     DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&SPI2->DR;          // Address of peripheral the DMA must map to
    
65.     DMA_InitStructure.DMA_MemoryBaseAddr     = (uint32_t)m_spi_dma_send_buf; // Variable from which data will be transmitted
    
66.     DMA_InitStructure.DMA_DIR                = DMA_DIR_PeripheralDST;
    
67.     DMA_InitStructure.DMA_BufferSize         = sizeof(m_spi_dma_send_buf);   //Buffer size
    
68.     DMA_InitStructure.DMA_PeripheralInc      = DMA_PeripheralInc_Disable;
    
69.     DMA_InitStructure.DMA_MemoryInc          = DMA_MemoryInc_Enable;
    
70.     DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
    
71.     DMA_InitStructure.DMA_MemoryDataSize     = DMA_PeripheralDataSize_Byte;
    
72.     DMA_InitStructure.DMA_Mode               = DMA_Mode_Normal;
    
73.     DMA_InitStructure.DMA_Priority           = DMA_Priority_High;
    
74.     DMA_InitStructure.DMA_M2M                = DMA_M2M_Disable;
    
75. 
    
76.     DMA_Init(DMA1_Channel5, &DMA_InitStructure);
    
77. 
    
78. #endif
    
79.    
    
80.     // enable transfer complete & error interrupt
    
81.     NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel5_IRQn;
    
82.     NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
    
83.     NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
    
84.     NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    
85.     NVIC_Init(&NVIC_InitStructure);
    
86.     DMA_ITConfig(DMA1_Channel5, DMA_IT_TC | DMA_IT_TE, ENABLE);
    
87. 
    
88.     // enable the dma channel of receiving
    
89.     DMA_Cmd(DMA1_Channel4, ENABLE); //Enable the DMA1 - Channel4   
    
90. 
    
91. 
    
92.     SPI_Cmd(SPI2, DISABLE);
    
93.     SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
    
94.     SPI_InitStructure.SPI_Mode = SPI_Mode_Slave;
    
95.     SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
    
96.     SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;
    
97.     SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;
    
98.     SPI_InitStructure.SPI_NSS =  SPI_NSS_Hard;
    
99.     SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
    
100.     SPI_InitStructure.SPI_CRCPolynomial = 7;
     
101.     SPI_Init(SPI2, &SPI_InitStructure);
     
102. 
     
103.     // enable spi error interrupt
     
104.     NVIC_InitStructure.NVIC_IRQChannel = SPI2_IRQn;
     
105.     NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
     
106.     NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
     
107.     NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
     
108.     NVIC_Init(&NVIC_InitStructure);
     
109.     SPI_I2S_ClearFlag(SPI2, SPI_I2S_FLAG_TXE);
     
110.     SPI_I2S_ClearFlag(SPI2, SPI_FLAG_MODF);
     
111.     SPI_I2S_ITConfig(SPI2, SPI_I2S_IT_ERR, ENABLE);
     
112.    
     
113.     // enable dma receive and transmit
     
114.     SPI_I2S_DMACmd(SPI2, SPI_I2S_DMAReq_Rx | SPI_I2S_DMAReq_Tx, ENABLE);
     
115.    
     
116.     // enable spi2 device
     
117.     SPI_Cmd(SPI2, ENABLE);
     
118. }

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        2： 发送代码

1. 
   
2. /*
   
3. * @brief: send data via the spi bus.
   
4. * @param ack: pointer to the buffer of ack data.
   
5. * @param ack_size: size of the ack buffer.
   
6. * @param buf: pointer to the data buffer that real be send.
   
7. * @param size: size of real data.
   
8. */
   
9. void board_spi_send(uint8_t *ack, int ack_size, uint8_t *buf, int size) {
   
10.     int i, index = 0;
    
11. 
    
12.     // copy ACK data to memory
    
13.     if (ack != null) {
    
14.         for (i = 0; i < ack_size; i++) {
    
15.             m_spi_dma_send_buf[index++] = *ack++;
    
16.         }
    
17.     }
    
18.     // copy real data to memory
    
19.     if (buf != null) {
    
20.         for (i = 0; i < size; i++) {
    
21.             m_spi_dma_send_buf[index++] = *buf++;
    
22.         }
    
23.     }
    
24.     // finally, it has data to send.
    
25.     if (index != 0) {
    
26. #if 1
    
27.         DBG_INFO("Fill data intp DMA => ");
    
28.         for (i = 0; i < index; i++) {
    
29.             printf("0x%02x ", m_spi_dma_send_buf[i]);
    
30.         }
    
31.         printf(" ");
    
32. #endif
    
33.         // wait for the dma finish its work.
    
34.         while ((m_spi_is_sending == true || m_spi_dma_waiting_send == true) && (DMA1_Channel5->CCR & DMA_CCR5_EN));
    
35.         // disable dma channel
    
36.         DMA1_Channel5->CCR &= (uint16_t)(~DMA_CCR5_EN);
    
37.         m_spi_is_sending = false;
    
38.         // use to indicate that we are waiting for sending.
    
39.         m_spi_dma_waiting_send = true;
    
40.         // re-config the address and size
    
41.         DMA1_Channel5->CMAR = (uint32_t)m_spi_dma_send_buf;
    
42.         // set the buffer size
    
43.         DMA1_Channel5->CNDTR = index;
    
44.     } else {
    
45.         printf("nothing send to spi ");
    
46.     }
    
47. }

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        3： CS 中断

1. //
   
2. // interrupt handler routine for spi cs
   
3. void EXTI15_10_IRQHandler(void) {
   
4.    
   
5.     // the master start to transfer
   
6.     if (EXTI_GetITStatus(EXTI_Line12) != RESET) {
   
7.         // check whether there are some data waiting for sending.
   
8.         if (m_spi_dma_waiting_send == true) {
   
9.             DBG_INFO("enable spi send. size = %d ", DMA1_Channel5->CNDTR);
   
10.             // set this variable to indicate that we are sending.
    
11.             m_spi_is_sending = true;
    
12.             // unmark this variable.
    
13.             m_spi_dma_waiting_send = false;
    
14.             // enable the transmit DMA channel.
    
15.             DMA1_Channel5->CCR |= DMA_CCR5_EN;
    
16.         }
    
17.         EXTI_ClearITPendingBit(EXTI_Line12);
    
18.     }  
    
19. }

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        4：DMA 中断

1. void DMA1_Channel5_IRQHandler(void) {
   
2. 
   
3.     if (DMA_GetITStatus(DMA1_IT_TC5) != RESET) {
   
4.         DBG_INFO("DMA_INT=> send ack ok! remain size = %d ", DMA1_Channel5->CNDTR);
   
5.         // disable the dma channel
   
6.         DMA1_Channel5->CCR &= (uint16_t)(~DMA_CCR5_EN);
   
7.         m_spi_is_sending = false;
   
8.         DMA_ClearITPendingBit(DMA1_IT_TC5);
   
9.     }
   
10.    
    
11.     if (DMA_GetITStatus(DMA1_IT_TE5) != RESET) {
    
12.         DBG_ERROR("some error occured while sending... ");
    
13.         // disable the dma channel
    
14.         DMA1_Channel5->CCR &= (uint16_t)(~DMA_CCR5_EN);
    
15.         m_spi_is_sending = false;
    
16.         DMA_ClearITPendingBit(DMA1_IT_TE5);
    
17.     }
    
18. }

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        5： SPI 中断

1. void SPI2_IRQHandler(void) {
   
2. 
   
3.     if (SPI_I2S_GetITStatus(SPI2, SPI_I2S_IT_OVR)) {
   
4.         DBG_ERROR("spi2 receive overrun! ");
   
5.         SPI_I2S_ClearITPendingBit(SPI2, SPI_I2S_IT_OVR);
   
6.     }
   
7.     if (SPI_I2S_GetITStatus(SPI2, SPI_IT_CRCERR)) {
   
8.         DBG_ERROR("spi2 crc error! ");
   
9.         SPI_I2S_ClearITPendingBit(SPI2, SPI_IT_CRCERR);
   
10.     }
    
11. 
    
12.     if (SPI_I2S_GetITStatus(SPI2, SPI_IT_MODF)) {
    
13.         DBG_ERROR("spi2 mode error! ");
    
14.         SPI_I2S_ClearITPendingBit(SPI2, SPI_IT_MODF);
    
15.     }
    
16. }

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错误现象：

        调试图片.png (363.97 KB, 下载次数: 0) 下载附件 2018-5-28 14:37 上传

DMA在发送完第一个字节数据后， 跳过了第二个， 直接发送第三个了。。。。。。

看过这个时候的DMA控制寄存器， 值为 209a   字节单位没有改， 都是 Byte。 而且在整个过程中， SPI 和 DMA的错误中断都没有触发！ 希望大家帮忙分析一下。。。。