Restart DMA - STM32F767

[Pilous Droip]

Posted on January 30, 2018 at 11:35

Hello.

I have question. How to restart DMA?

I have this init function:

&sharpdefine DMA_RX_BUFF_SIZE            64         

uint8_t dma_rx_buff[DMA_RX_BUFF_SIZE];

void MX_UART5_Init(void)

{ /* Enable CLOCK for GPIO */ LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_GPIOC); LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_GPIOD);

/* Enable Clock for UART5 */

LL_RCC_SetUARTClockSource(LL_RCC_UART5_CLKSOURCE_HSI);

/* Peripheral clock enable */

LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_UART5); LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_DMA1);

/* create structure */

LL_USART_InitTypeDef USART_InitStruct; LL_GPIO_InitTypeDef GPIO_InitStruct;

/**

* UART5 GPIO Configuration * PC12 ------> UART5_TX * PD2 ------> UART5_RX */ GPIO_InitStruct.Pin = LL_GPIO_PIN_12; GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE; GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_VERY_HIGH; GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL; GPIO_InitStruct.Pull = LL_GPIO_PULL_UP; GPIO_InitStruct.Alternate = LL_GPIO_AF_8; LL_GPIO_Init(GPIOC, &GPIO_InitStruct);

GPIO_InitStruct.Pin = LL_GPIO_PIN_2;

GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE; GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_VERY_HIGH; GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL; GPIO_InitStruct.Pull = LL_GPIO_PULL_UP; GPIO_InitStruct.Alternate = LL_GPIO_AF_8; LL_GPIO_Init(GPIOD, &GPIO_InitStruct);

/* Init DMA */

/* For UART5 -> STREAM - 0, CHANNEL = 4 */ LL_DMA_SetChannelSelection(DMA1, LL_DMA_STREAM_0, LL_DMA_CHANNEL_4); LL_DMA_SetDataTransferDirection(DMA1, LL_DMA_STREAM_0, LL_DMA_DIRECTION_PERIPH_TO_MEMORY); LL_DMA_SetStreamPriorityLevel(DMA1, LL_DMA_STREAM_0, LL_DMA_PRIORITY_LOW); LL_DMA_SetMode(DMA1, LL_DMA_STREAM_0, LL_DMA_MODE_NORMAL); LL_DMA_SetPeriphIncMode(DMA1, LL_DMA_STREAM_0, LL_DMA_PERIPH_NOINCREMENT); LL_DMA_SetMemoryIncMode(DMA1, LL_DMA_STREAM_0, LL_DMA_MEMORY_INCREMENT); LL_DMA_SetPeriphSize(DMA1, LL_DMA_STREAM_0, LL_DMA_PDATAALIGN_BYTE); LL_DMA_SetMemorySize(DMA1, LL_DMA_STREAM_0, LL_DMA_MDATAALIGN_BYTE); LL_DMA_DisableFifoMode(DMA1, LL_DMA_STREAM_0); LL_DMA_SetMemoryAddress(DMA1, LL_DMA_STREAM_0, (uint32_t)dma_rx_buff); LL_DMA_SetDataLength(DMA1, LL_DMA_STREAM_0, sizeof(dma_rx_buff)); LL_DMA_SetPeriphAddress(DMA1, LL_DMA_STREAM_0, (uint32_t)&UART5->RDR); //LL_DMA_EnableIT_HT(DMA1, LL_DMA_STREAM_0); //LL_DMA_EnableIT_TC(DMA1, LL_DMA_STREAM_0); LL_DMA_EnableStream(DMA1, LL_DMA_STREAM_0);

/* init for UART5 */

USART_InitStruct.BaudRate = 115200; USART_InitStruct.DataWidth = LL_USART_DATAWIDTH_8B; USART_InitStruct.StopBits = LL_USART_STOPBITS_1; USART_InitStruct.Parity = LL_USART_PARITY_NONE; USART_InitStruct.TransferDirection = LL_USART_DIRECTION_TX_RX; USART_InitStruct.HardwareFlowControl = LL_USART_HWCONTROL_NONE; USART_InitStruct.OverSampling = LL_USART_OVERSAMPLING_16; LL_USART_Init(UART5, &USART_InitStruct);

LL_USART_Init(UART5, &USART_InitStruct);

LL_USART_ConfigAsyncMode(UART5); LL_USART_EnableDMAReq_RX(UART5); //LL_USART_EnableIT_IDLE(UART5);

LL_USART_EnableRxTimeout(UART5);

LL_USART_SetRxTimeout(UART5, 115); LL_USART_EnableIT_RTO(UART5); LL_USART_Enable(UART5); NVIC_SetPriority(UART5_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(), 0, 0)); NVIC_EnableIRQ(UART5_IRQn);

}

And this funtion:

void UART5_IRQHandler(void) {

uint16_t pos; /** * Check for idle line detection on USART */ if (LL_USART_IsActiveFlag_RTO(UART5)) //kontrola, zda je preruseni od TIMER Rx uartu { LL_USART_ClearFlag_RTO(UART5); //smazu priznak

prijatych_znaku=DMA_RX_BUFF_SIZE-LL_DMA_GetDataLength(DMA1, LL_DMA_STREAM_0);

itoa(prijatych_znaku, buffer, 10);

process_usart_data(buffer, strlen(prijatych_znaku));

LL_DMA_DisableStream(DMA1, LL_DMA_STREAM_0);

LL_DMA_SetMemoryAddress(DMA1, LL_DMA_STREAM_0, (uint32_t)dma_rx_buff); LL_DMA_SetDataLength(DMA1, LL_DMA_STREAM_0, sizeof(dma_rx_buff)); LL_DMA_EnableStream(DMA1, LL_DMA_STREAM_0); }}

And when I receive data I print lenght of receive data. And my receive data show as:

• --> Send from PC
  • Hello\r\n
• <-- Return to PC
  • 7
• -->Send from PC
  • Hello\r\n
• <-- Return to PC
  • 0

I would expect 7, not 0.

#uart-dma #stm32f767

[Pilous Droip]

Posted on January 30, 2018 at 12:41

I modificate this function:

void UART5_IRQHandler(void)

{

if (LL_USART_IsActiveFlag_RTO(UART5)) //check RTO uart

{ LL_USART_ClearFlag_RTO(UART5); //delete flag

receive_char=DMA_RX_BUFF_SIZE-LL_DMA_GetDataLength(DMA1, LL_DMA_STREAM_0);

itoa(

receive_char

, buffer, 10); usart_puts(buffer); usart_puts(''\r\nNEW:'');

LL_DMA_DisableStream(DMA1, LL_DMA_STREAM_0);

LL_DMA_SetDataLength(DMA1, LL_DMA_STREAM_0, sizeof(dma_rx_buff)); LL_DMA_SetMemoryAddress(DMA1, LL_DMA_STREAM_0, (uint32_t)dma_rx_buff); LL_DMA_EnableStream(DMA1, LL_DMA_STREAM_0); }}

And when I send first string, MCU return good value (7), but after this it is return only 0. And it is wrong value. Any idea, what is wrong?

Yellow: data from PC

Black: data from MCU

[waclawek.jan]

Posted on January 30, 2018 at 13:11

Read out and check/post the content of relevant DMA registers (including status) at the beginning of ISR.

JW

[Pilous Droip]

Posted on January 30, 2018 at 13:12

Sorry, but I don't understand. How do you think? 

[waclawek.jan]

Posted on January 30, 2018 at 13:27

The simplest way is to put a breakpoint at the beginning of the ISR and read out the registers using the registers view of debugger.

If you don't use a debugger, you can write code to do that at the beginning of ISR and then send the result to PC or visualize in any other way you prefer.

JW

[Pilous Droip]

Posted on January 30, 2018 at 17:43

Ok. So I look on register of DMA1 and I see one problem. Register: 

DMA_SxCR_EN 

isn't set to 1, when I restart my DMA. But I don't know why.

void UART5_IRQHandler(void)

{

if (LL_USART_IsActiveFlag_RTO(UART5)) 

LL_USART_ClearFlag_RTO(UART5); 

prijatych_znaku=DMA_RX_BUFF_SIZE-LL_DMA_GetDataLength(DMA1, LL_DMA_STREAM_0);

itoa(prijatych_znaku, buffer, 10); usart_puts(buffer); usart_puts(''\r\nNEW:'');

LL_DMA_DisableStream(DMA1, LL_DMA_STREAM_0);

LL_DMA_SetMemoryAddress(DMA1, LL_DMA_STREAM_0, (uint32_t)dma_rx_buff); LL_DMA_SetDataLength(DMA1, LL_DMA_STREAM_0, sizeof(dma_rx_buff)); LL_DMA_EnableStream(DMA1, LL_DMA_STREAM_0); // this set 

DMA_SxCR_EN  (problem!!!?)

LL_GPIO_TogglePin(GPIOB, LL_GPIO_PIN_14);

asm(''NOP'');   //only for debugging

}}

But you can see in function, that I set this register.

[Pilous Droip]

Posted on January 30, 2018 at 18:44

Ok. Problem was solved.

Here is init:

void MX_UART5_Init(void)

{ /* Enable CLOCK for GPIO */ LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_GPIOC); LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_GPIOD);

/* Enable Clock for UART5 */

LL_RCC_SetUARTClockSource(LL_RCC_UART5_CLKSOURCE_HSI);

/* Peripheral clock enable */

LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_UART5); LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_DMA1);

/* create structure */

LL_USART_InitTypeDef USART_InitStruct; LL_GPIO_InitTypeDef GPIO_InitStruct;

/**

* UART5 GPIO Configuration * PC12 ------> UART5_TX * PD2 ------> UART5_RX */ GPIO_InitStruct.Pin = LL_GPIO_PIN_12; GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE; GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_VERY_HIGH; GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL; GPIO_InitStruct.Pull = LL_GPIO_PULL_UP; GPIO_InitStruct.Alternate = LL_GPIO_AF_8; LL_GPIO_Init(GPIOC, &GPIO_InitStruct);

GPIO_InitStruct.Pin = LL_GPIO_PIN_2;

GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE; GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_VERY_HIGH; GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL; GPIO_InitStruct.Pull = LL_GPIO_PULL_UP; GPIO_InitStruct.Alternate = LL_GPIO_AF_8; LL_GPIO_Init(GPIOD, &GPIO_InitStruct);

/* Init DMA */

/* For UART5 -> STREAM - 0, CHANNEL = 4 */ LL_DMA_SetChannelSelection(DMA1, LL_DMA_STREAM_0, LL_DMA_CHANNEL_4); LL_DMA_SetDataTransferDirection(DMA1, LL_DMA_STREAM_0, LL_DMA_DIRECTION_PERIPH_TO_MEMORY); LL_DMA_SetStreamPriorityLevel(DMA1, LL_DMA_STREAM_0, LL_DMA_PRIORITY_LOW); LL_DMA_SetMode(DMA1, LL_DMA_STREAM_0, LL_DMA_MODE_NORMAL); LL_DMA_SetPeriphIncMode(DMA1, LL_DMA_STREAM_0, LL_DMA_PERIPH_NOINCREMENT); LL_DMA_SetMemoryIncMode(DMA1, LL_DMA_STREAM_0, LL_DMA_MEMORY_INCREMENT); LL_DMA_SetPeriphSize(DMA1, LL_DMA_STREAM_0, LL_DMA_PDATAALIGN_BYTE); LL_DMA_SetMemorySize(DMA1, LL_DMA_STREAM_0, LL_DMA_MDATAALIGN_BYTE); LL_DMA_DisableFifoMode(DMA1, LL_DMA_STREAM_0); LL_DMA_SetMemoryAddress(DMA1, LL_DMA_STREAM_0, (uint32_t)dma_rx_buff); LL_DMA_SetDataLength(DMA1, LL_DMA_STREAM_0, sizeof(dma_rx_buff)); LL_DMA_SetPeriphAddress(DMA1, LL_DMA_STREAM_0, (uint32_t)&UART5->RDR); LL_DMA_EnableStream(DMA1, LL_DMA_STREAM_0);

/* init for UART5 */

USART_InitStruct.BaudRate = 115200; USART_InitStruct.DataWidth = LL_USART_DATAWIDTH_8B; USART_InitStruct.StopBits = LL_USART_STOPBITS_1; USART_InitStruct.Parity = LL_USART_PARITY_NONE; USART_InitStruct.TransferDirection = LL_USART_DIRECTION_TX_RX; USART_InitStruct.HardwareFlowControl = LL_USART_HWCONTROL_NONE; USART_InitStruct.OverSampling = LL_USART_OVERSAMPLING_16; LL_USART_Init(UART5, &USART_InitStruct);

LL_USART_ConfigAsyncMode(UART5);

LL_USART_EnableDMAReq_RX(UART5);

LL_USART_EnableRxTimeout(UART5);

LL_USART_SetRxTimeout(UART5, 115); LL_USART_EnableIT_RTO(UART5); LL_USART_Enable(UART5); NVIC_SetPriority(UART5_IRQn, NVIC_EncodePriority(NVIC_GetPriorityGrouping(), 0, 0)); NVIC_EnableIRQ(UART5_IRQn);

}

And interrupt is here.

void UART5_IRQHandler(void)

{

if (LL_USART_IsActiveFlag_RTO(UART5)) //kontrola, zda je preruseni od TIMER Rx uartu

{ LL_USART_ClearFlag_RTO(UART5); //smazu priznak

prijatych_znaku=DMA_RX_BUFF_SIZE-LL_DMA_GetDataLength(DMA1, LL_DMA_STREAM_0);

itoa(prijatych_znaku, buffer, 10); usart_puts(buffer); usart_puts('\r\nNEW:');

LL_DMA_DisableStream(DMA1, LL_DMA_STREAM_0);

LL_DMA_SetMemoryAddress(DMA1, LL_DMA_STREAM_0, (uint32_t)dma_rx_buff); LL_DMA_SetDataLength(DMA1, LL_DMA_STREAM_0, sizeof(dma_rx_buff)); LL_DMA_ClearFlag_TE0(DMA1); LL_DMA_ClearFlag_TC0(DMA1); LL_DMA_EnableStream(DMA1, LL_DMA_STREAM_0);

LL_GPIO_TogglePin(GPIOB, LL_GPIO_PIN_14);

asm('NOP');

}}

And problem was: 

1. Clear FLAG TCIF
2. Clear FLAG TEIF

It is ALL.

🙂

 

🙂

 

🙂