Associate II

Question

Problem with UART transmission, while Timer interrupt is enable. STM32F411

Forum|Forum|3 years ago
July 5, 2023
16 replies
6445 views

I want to read the data from UART and write it to the GPIO port which is connected to the 16 bit DAC.

I am facing problem as any UART1 or UART2 is not working when Timer interrupt is enabled.

100MHz CPU clock and 50MHz Timer 4 clock with the PWM output on Channel 3 of 12MHz, timer count 8 and pulse count 4. Using Half pules complete callback to write data on GPIo ODR registor. At the same time also receive data from UART. But the UART receive function is not working.

The timer interrupt routine is working but unable to receive data from UART. Is this due to the MCU is busy executing interrupt routine as this routine is call after every 16 CPU Clock cycles and thus that are no enough to execute UART Receive function.

What is the solution for this?

This topic has been closed for replies.

Tesla DeLorean

Guru

Interrupting beyond several hundred KHz is impractical, and made worse by the convoluted nature of the HAL and its callbacks, etc.

If you want to read or write patterns to a GPIO bank, use DMA, with the memory vs GPIO ODR, IDR or BSRR registers. Decimate the interrupt loading with an adequately long DMA transfer size, begin circular, and managing interaction via the HT and TC DMA interrupts.

Tips, Buy me a coffee, or three.. PayPal Venmo (See Profile) Up vote any posts that you find helpful, it shows what's working..

Yash JasnaniAuthor

Associate II

Thanks for the suggestion I will try that also.

Please find full details in reply section https://community.st.com/t5/stm32cubeide-mcu/problem-with-uart-transmission-while-timer-interrupt-is...

Bob S

Super User

First off, "UART receive function is not working" is not helpful. In general, don't just say something isn't working, explain HOW it doesn't work. For example, do you get some but not all data? Do you get data but is not what you expect? etc.

So we are back to "explain how your UART isn't working".

In your case, you are correct - your timer IRQ is starving the CPU. I don't think your timer IRQ is really getting called every 16 CPU cycles - that is just not possible if the IRQ function does ANYTHING. Just pushing registers on the stack and then popping them back off probably takes longer than that.

If your PWM freq is 12MHz and it counts to 8 before resetting/reloading, that is a PWM period of 12MHz/8 = 1.5MHz. And an IRQ at "half complete" would be 2 PWM periods, or 0.75MHz (750KHz). The CPU should be able to handle THAT interrupt rate, unless your callback has lots of code in it.

Yash JasnaniAuthor

Associate II

I Apologize for that.

Sorry I have missed multipler 2x which is before Timer clock on APB1 bus.

So Timer4 have 100MHz clock, So 1 Tick is 10ns.

As per my calculations for 12.5MHz T=80ns , so 8 Ticks gives us 80ns.

Therefore Counter Period = 8-1 and Pulse Value = 4.

Please find full details in reply section https://community.st.com/t5/stm32cubeide-mcu/problem-with-uart-transmission-while-timer-interrupt-is...

Karl Yamashita

Principal

As @Bob S indicated, "UART receive function is not working" doesn't give us much information. You didn't indicate if you're polling or using UART interrupt? Posting your code would be even better.

If a reply has proven helpful, click on Accept as Solution so that it'll show at top of the post.CAN Jammer an open source CAN bus hacking toolCANableV3 Open Source

Yash JasnaniAuthor

Associate II

I apologie for that. I am using UART with DMA. I have tried polling mode and Interrupt mode, but still unable to receive data.

Please find full details in reply section https://community.st.com/t5/stm32cubeide-mcu/problem-with-uart-transmission-while-timer-interrupt-is...

Bob S

Super User

In my previous post I said:

> If your PWM freq is 12MHz and it counts to 8 before resetting/reloading, [snip]

Oh man, THAT ^^^ is not correct. Let me try again... Your original post said:

> 100MHz CPU clock and 50MHz Timer 4 clock with the PWM output on
> Channel 3 of 12MHz, timer count 8 and pulse count 4.

Hmmm... 50MHz TIM4 clock with a (I presume max) count of 8 does not give you 12MHz PWM freq. It gives you 12MHz/8 = 1.5 MHz. And there is no way to get a 12 MHz PWM from a 50 MHz timer clock (would need to divide by 4.167. So maybe divide by 4 to get 12.5 MHz?

So, yeah, as @Karl Yamashita said - post your code - UART and timer config so we can see what your PWM is really doing, plus your timer and dma IRQ callbacks and any code that deals with the UART.

Yash JasnaniAuthor

Associate II

Sorry I have multipler 2x which is before Timer clock on APB1 bus.

So Timer4 have 100MHz clock, So 1 Tick is 10ns.

As per my calculations for 12.5MHz T=80ns , so 8 Ticks gives us 80ns.

Therefore Counter Period = 8-1 and Pulse Value = 4.

Please find full details in reply section https://community.st.com/t5/stm32cubeide-mcu/problem-with-uart-transmission-while-timer-interrupt-is...

KnarfB

Super User

> Using Half pules complete callback to write data on GPIo ODR registor

Why not using a timer channel in PWM output mode, i.e. a PWM-capable pin, and no interrupt handler at all?

hth

KnarfB

Yash JasnaniAuthor

Associate II

I have used PWM output mode with timer 4 at channel 3 pin B8 for clock generation. On Half pules complete callback i write 16 bit data to GPIOA->ODR (LSB) and GPIOB->ODR (MSB).

Please find full details in reply section https://community.st.com/t5/stm32cubeide-mcu/problem-with-uart-transmission-while-timer-interrupt-is-enable/m-p/572482/highlight/true#M18951

Yash JasnaniAuthor

Associate II

I think I missed the problem explanation, sorry for that.

Please find the detailed information below -
To Achieve -
1- Need to create DAC (Digital to Analog) Interface.
2- Receive data from UART ( I have chosen UART because of DMA support) (USB option is also available but I think DMA support option is not available on STCube IDE).
3- Send the data (received from UART) to DAC which is connected to GPIOA (A0 to A7) LSB and GPIOB MSB (B0 to B7)
4- Generate CLK of 12MHz / 12.5MHz.

Facing issues -
1- Unable to receive data when the PWM timer interrupt is enabled (using this function in main.c file - HAL_TIM_PWM_Start_IT(&htim4, TIM_CHANNEL_3);
but , getting data when I disabled the PWM timer interrupt (HAL_TIM_PWM_Start(&htim4, TIM_CHANNEL_3);.

I have done calculation for timer 4 to generate CLK, the details -

APB1 Timer Clock :- 100MHz, so T=10ns.
1 Tick = 10ns, so for 12.5MHz, T=80ns.
Therefore Counter Period = 8 Ticks.
For 50% duty cycle Pulse value = 4.
Please see the reference image 01 -
Pin ConfigCLK ConfigGPIO ConfigTimer4 ConfigUART1 ConfigUART1 DMA ConfigUART1 NVIC ConfigTimer4 NIVC Config

main.c program

/******************************main.c*******************************/
/* USER CODE BEGIN Header */
/**
 ******************************************************************************
 * @file : main.c
 * @brief : Main program body
 ******************************************************************************
 * @attention
 *
 * Copyright (c) 2023 STMicroelectronics.
 * All rights reserved.
 *
 * This software is licensed under terms that can be found in the LICENSE file
 * in the root directory of this software component.
 * If no LICENSE file comes with this software, it is provided AS-IS.
 *
 ******************************************************************************
 */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */

/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/
TIM_HandleTypeDef htim4;

UART_HandleTypeDef huart1;
DMA_HandleTypeDef hdma_usart1_rx;

/* USER CODE BEGIN PV */
int16_t buf[4] = { 0xFFFF, 0x8000, 0x0000, 0x7FFF };
uint8_t rx_buf[100] = { 0 };
int i = 0;
/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_TIM4_Init(void);
static void MX_USART1_UART_Init(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

/**
 * @brief The application entry point.
 * @retval int
 */
int main(void) {
	/* USER CODE BEGIN 1 */

	/* USER CODE END 1 */

	/* MCU Configuration--------------------------------------------------------*/

	/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
	HAL_Init();

	/* USER CODE BEGIN Init */

	/* USER CODE END Init */

	/* Configure the system clock */
	SystemClock_Config();

	/* USER CODE BEGIN SysInit */

	/* USER CODE END SysInit */

	/* Initialize all configured peripherals */
	MX_GPIO_Init();
	MX_DMA_Init();
	MX_TIM4_Init();
	MX_USART1_UART_Init();
	/* USER CODE BEGIN 2 */

	HAL_TIM_PWM_Start_IT(&htim4, TIM_CHANNEL_3);
	HAL_UART_Receive_DMA(&huart1, rx_buf, sizeof(rx_buf));

	/* USER CODE END 2 */

	/* Infinite loop */
	/* USER CODE BEGIN WHILE */
	while (1) {
		/* USER CODE END WHILE */

		/* USER CODE BEGIN 3 */

//		GPIOA->ODR = (uint32_t) (buf[i] & 0x00FF);
//		GPIOB->ODR = (uint32_t) ((buf[i] >> 8) & 0x00FF);
//		i++;
//		if (i == 4)
//			i = 0;
	}
	/* USER CODE END 3 */
}

/**
 * @brief System Clock Configuration
 * @retval None
 */
void SystemClock_Config(void) {
	RCC_OscInitTypeDef RCC_OscInitStruct = { 0 };
	RCC_ClkInitTypeDef RCC_ClkInitStruct = { 0 };

	/** Configure the main internal regulator output voltage
	 */
	__HAL_RCC_PWR_CLK_ENABLE();
	__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

	/** Initializes the RCC Oscillators according to the specified parameters
	 * in the RCC_OscInitTypeDef structure.
	 */
	RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
	RCC_OscInitStruct.HSEState = RCC_HSE_ON;
	RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
	RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
	RCC_OscInitStruct.PLL.PLLM = 12;
	RCC_OscInitStruct.PLL.PLLN = 96;
	RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
	RCC_OscInitStruct.PLL.PLLQ = 4;
	if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
		Error_Handler();
	}

	/** Initializes the CPU, AHB and APB buses clocks
	 */
	RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK
			| RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2;
	RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
	RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
	RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
	RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

	if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_3) != HAL_OK) {
		Error_Handler();
	}
}

/**
 * @brief TIM4 Initialization Function
 * @PAram None
 * @retval None
 */
static void MX_TIM4_Init(void) {

	/* USER CODE BEGIN TIM4_Init 0 */

	/* USER CODE END TIM4_Init 0 */

	TIM_ClockConfigTypeDef sClockSourceConfig = { 0 };
	TIM_MasterConfigTypeDef sMasterConfig = { 0 };
	TIM_OC_InitTypeDef sConfigOC = { 0 };

	/* USER CODE BEGIN TIM4_Init 1 */

	/* USER CODE END TIM4_Init 1 */
	htim4.Instance = TIM4;
	htim4.Init.Prescaler = 0;
	htim4.Init.CounterMode = TIM_COUNTERMODE_UP;
	htim4.Init.Period = 8 - 1;
	htim4.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
	htim4.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
	if (HAL_TIM_Base_Init(&htim4) != HAL_OK) {
		Error_Handler();
	}
	sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
	if (HAL_TIM_ConfigClockSource(&htim4, &sClockSourceConfig) != HAL_OK) {
		Error_Handler();
	}
	if (HAL_TIM_PWM_Init(&htim4) != HAL_OK) {
		Error_Handler();
	}
	sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
	sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
	if (HAL_TIMEx_MasterConfigSynchronization(&htim4, &sMasterConfig)
			!= HAL_OK) {
		Error_Handler();
	}
	sConfigOC.OCMode = TIM_OCMODE_PWM1;
	sConfigOC.Pulse = 4;
	sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
	sConfigOC.OCFastMode = TIM_OCFAST_ENABLE;
	if (HAL_TIM_PWM_ConfigChannel(&htim4, &sConfigOC, TIM_CHANNEL_3)
			!= HAL_OK) {
		Error_Handler();
	}
	/* USER CODE BEGIN TIM4_Init 2 */

	/* USER CODE END TIM4_Init 2 */
	HAL_TIM_MspPostInit(&htim4);

}

/**
 * @brief USART1 Initialization Function
 * @PAram None
 * @retval None
 */
static void MX_USART1_UART_Init(void) {

	/* USER CODE BEGIN USART1_Init 0 */

	/* USER CODE END USART1_Init 0 */

	/* USER CODE BEGIN USART1_Init 1 */

	/* USER CODE END USART1_Init 1 */
	huart1.Instance = USART1;
	huart1.Init.BaudRate = 115200;
	huart1.Init.WordLength = UART_WORDLENGTH_8B;
	huart1.Init.StopBits = UART_STOPBITS_1;
	huart1.Init.Parity = UART_PARITY_NONE;
	huart1.Init.Mode = UART_MODE_TX_RX;
	huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
	huart1.Init.OverSampling = UART_OVERSAMPLING_16;
	if (HAL_UART_Init(&huart1) != HAL_OK) {
		Error_Handler();
	}
	/* USER CODE BEGIN USART1_Init 2 */

	/* USER CODE END USART1_Init 2 */

}

/**
 * Enable DMA controller clock
 */
static void MX_DMA_Init(void) {

	/* DMA controller clock enable */
	__HAL_RCC_DMA2_CLK_ENABLE();

	/* DMA interrupt init */
	/* DMA2_Stream2_IRQn interrupt configuration */
	HAL_NVIC_SetPriority(DMA2_Stream2_IRQn, 0, 0);
	HAL_NVIC_EnableIRQ(DMA2_Stream2_IRQn);

}

/**
 * @brief GPIO Initialization Function
 * @PAram None
 * @retval None
 */
static void MX_GPIO_Init(void) {
	GPIO_InitTypeDef GPIO_InitStruct = { 0 };
	/* USER CODE BEGIN MX_GPIO_Init_1 */
	/* USER CODE END MX_GPIO_Init_1 */

	/* GPIO Ports Clock Enable */
	__HAL_RCC_GPIOC_CLK_ENABLE();
	__HAL_RCC_GPIOH_CLK_ENABLE();
	__HAL_RCC_GPIOA_CLK_ENABLE();
	__HAL_RCC_GPIOB_CLK_ENABLE();

	/*Configure GPIO pin Output Level */
	HAL_GPIO_WritePin(GPIOC, GPIO_PIN_13, GPIO_PIN_RESET);

	/*Configure GPIO pin Output Level */
	HAL_GPIO_WritePin(GPIOA,
			GPIO_PIN_0 | GPIO_PIN_1 | GPIO_PIN_4 | GPIO_PIN_5 | GPIO_PIN_6
					| GPIO_PIN_7, GPIO_PIN_RESET);

	/*Configure GPIO pin Output Level */
	HAL_GPIO_WritePin(GPIOB,
			GPIO_PIN_0 | GPIO_PIN_1 | GPIO_PIN_2 | GPIO_PIN_3 | GPIO_PIN_4
					| GPIO_PIN_5 | GPIO_PIN_6 | GPIO_PIN_7, GPIO_PIN_RESET);

	/*Configure GPIO pin : PC13 */
	GPIO_InitStruct.Pin = GPIO_PIN_13;
	GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
	GPIO_InitStruct.Pull = GPIO_NOPULL;
	GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
	HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);

	/*Configure GPIO pins : PA0 PA1 PA4 PA5
	 PA6 PA7 */
	GPIO_InitStruct.Pin = GPIO_PIN_0 | GPIO_PIN_1 | GPIO_PIN_4 | GPIO_PIN_5
			| GPIO_PIN_6 | GPIO_PIN_7;
	GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
	GPIO_InitStruct.Pull = GPIO_PULLDOWN;
	GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
	HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

	/*Configure GPIO pins : PB0 PB1 PB2 PB3
	 PB4 PB5 PB6 PB7 */
	GPIO_InitStruct.Pin = GPIO_PIN_0 | GPIO_PIN_1 | GPIO_PIN_2 | GPIO_PIN_3
			| GPIO_PIN_4 | GPIO_PIN_5 | GPIO_PIN_6 | GPIO_PIN_7;
	GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
	GPIO_InitStruct.Pull = GPIO_PULLDOWN;
	GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
	HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

	/* USER CODE BEGIN MX_GPIO_Init_2 */
	/* USER CODE END MX_GPIO_Init_2 */
}

/* USER CODE BEGIN 4 */
//Whem using received data from UART
//void HAL_TIM_PWM_PulseFinishedHalfCpltCallback(TIM_HandleTypeDef *htim) {
//	GPIOA->ODR = (uint32_t) (rx_buf[i] & 0x00FF);
//	GPIOB->ODR = (uint32_t) ((rx_buf[i + 1]) & 0x00FF);
//	i++;
//	if (i == 100)
//		i = 0;
//}
//only to check Whether connections are ok!
void HAL_TIM_PWM_PulseFinishedHalfCpltCallback(TIM_HandleTypeDef *htim) {
	GPIOA->ODR = (uint32_t) (buf[i] & 0x00FF);
	GPIOB->ODR = (uint32_t) ((buf[i] >> 8) & 0x00FF);
	i++;
	if (i == 4)
		i = 0;
}

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
	HAL_UART_Receive_DMA(&huart1, rx_buf, sizeof(rx_buf));
}
/* USER CODE END 4 */

/**
 * @brief This function is executed in case of error occurrence.
 * @retval None
 */
void Error_Handler(void) {
	/* USER CODE BEGIN Error_Handler_Debug */
	/* User can add his own implementation to report the HAL error return state */
	__disable_irq();
	while (1) {
	}
	/* USER CODE END Error_Handler_Debug */
}

#ifdef USE_FULL_ASSERT
/**
 * @brief Reports the name of the source file and the source line number
 * where the assert_param error has occurred.
 * @PAram file: pointer to the source file name
 * @PAram line: assert_param error line source number
 * @retval None
 */
void assert_failed(uint8_t *file, uint32_t line)
{
 /* USER CODE BEGIN 6 */
 /* User can add his own implementation to report the file name and line number,
 ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
 /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */

stm32f4xx_it.c program

these two functions modified -
1- void USART1_IRQHandler(void)
2- void DMA2_Stream2_IRQHandler(void)

/* USER CODE BEGIN Header */
/**
 ******************************************************************************
 * @file stm32f4xx_it.c
 * @brief Interrupt Service Routines.
 ******************************************************************************
 * @attention
 *
 * Copyright (c) 2023 STMicroelectronics.
 * All rights reserved.
 *
 * This software is licensed under terms that can be found in the LICENSE file
 * in the root directory of this software component.
 * If no LICENSE file comes with this software, it is provided AS-IS.
 *
 ******************************************************************************
 */
/* USER CODE END Header */

/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "stm32f4xx_it.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN TD */

/* USER CODE END TD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */

/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

/* External variables --------------------------------------------------------*/
extern TIM_HandleTypeDef htim4;
extern DMA_HandleTypeDef hdma_usart1_rx;
extern UART_HandleTypeDef huart1;
/* USER CODE BEGIN EV */

/* USER CODE END EV */

/******************************************************************************/
/* Cortex-M4 Processor Interruption and Exception Handlers */
/******************************************************************************/
/**
 * @brief This function handles Non maskable interrupt.
 */
void NMI_Handler(void)
{
 /* USER CODE BEGIN NonMaskableInt_IRQn 0 */

 /* USER CODE END NonMaskableInt_IRQn 0 */
 /* USER CODE BEGIN NonMaskableInt_IRQn 1 */
	while (1) {
	}
 /* USER CODE END NonMaskableInt_IRQn 1 */
}

/**
 * @brief This function handles Hard fault interrupt.
 */
void HardFault_Handler(void)
{
 /* USER CODE BEGIN HardFault_IRQn 0 */

 /* USER CODE END HardFault_IRQn 0 */
 while (1)
 {
 /* USER CODE BEGIN W1_HardFault_IRQn 0 */
 /* USER CODE END W1_HardFault_IRQn 0 */
 }
}

/**
 * @brief This function handles Memory management fault.
 */
void MemManage_Handler(void)
{
 /* USER CODE BEGIN MemoryManagement_IRQn 0 */

 /* USER CODE END MemoryManagement_IRQn 0 */
 while (1)
 {
 /* USER CODE BEGIN W1_MemoryManagement_IRQn 0 */
 /* USER CODE END W1_MemoryManagement_IRQn 0 */
 }
}

/**
 * @brief This function handles Pre-fetch fault, memory access fault.
 */
void BusFault_Handler(void)
{
 /* USER CODE BEGIN BusFault_IRQn 0 */

 /* USER CODE END BusFault_IRQn 0 */
 while (1)
 {
 /* USER CODE BEGIN W1_BusFault_IRQn 0 */
 /* USER CODE END W1_BusFault_IRQn 0 */
 }
}

/**
 * @brief This function handles Undefined instruction or illegal state.
 */
void UsageFault_Handler(void)
{
 /* USER CODE BEGIN UsageFault_IRQn 0 */

 /* USER CODE END UsageFault_IRQn 0 */
 while (1)
 {
 /* USER CODE BEGIN W1_UsageFault_IRQn 0 */
 /* USER CODE END W1_UsageFault_IRQn 0 */
 }
}

/**
 * @brief This function handles System service call via SWI instruction.
 */
void SVC_Handler(void)
{
 /* USER CODE BEGIN SVCall_IRQn 0 */

 /* USER CODE END SVCall_IRQn 0 */
 /* USER CODE BEGIN SVCall_IRQn 1 */

 /* USER CODE END SVCall_IRQn 1 */
}

/**
 * @brief This function handles Debug monitor.
 */
void DebugMon_Handler(void)
{
 /* USER CODE BEGIN DebugMonitor_IRQn 0 */

 /* USER CODE END DebugMonitor_IRQn 0 */
 /* USER CODE BEGIN DebugMonitor_IRQn 1 */

 /* USER CODE END DebugMonitor_IRQn 1 */
}

/**
 * @brief This function handles Pendable request for system service.
 */
void PendSV_Handler(void)
{
 /* USER CODE BEGIN PendSV_IRQn 0 */

 /* USER CODE END PendSV_IRQn 0 */
 /* USER CODE BEGIN PendSV_IRQn 1 */

 /* USER CODE END PendSV_IRQn 1 */
}

/**
 * @brief This function handles System tick timer.
 */
void SysTick_Handler(void)
{
 /* USER CODE BEGIN SysTick_IRQn 0 */

 /* USER CODE END SysTick_IRQn 0 */
 HAL_IncTick();
 /* USER CODE BEGIN SysTick_IRQn 1 */

 /* USER CODE END SysTick_IRQn 1 */
}

/******************************************************************************/
/* STM32F4xx Peripheral Interrupt Handlers */
/* Add here the Interrupt Handlers for the used peripherals. */
/* For the available peripheral interrupt handler names, */
/* please refer to the startup file (startup_stm32f4xx.s). */
/******************************************************************************/

/**
 * @brief This function handles TIM4 global interrupt.
 */
void TIM4_IRQHandler(void)
{
 /* USER CODE BEGIN TIM4_IRQn 0 */

 /* USER CODE END TIM4_IRQn 0 */
 HAL_TIM_IRQHandler(&htim4);
 /* USER CODE BEGIN TIM4_IRQn 1 */
 HAL_TIM_PWM_PulseFinishedHalfCpltCallback(&htim4);
 /* USER CODE END TIM4_IRQn 1 */
}

/**
 * @brief This function handles USART1 global interrupt.
 */
void USART1_IRQHandler(void)
{
 /* USER CODE BEGIN USART1_IRQn 0 */

 /* USER CODE END USART1_IRQn 0 */
 HAL_UART_IRQHandler(&huart1);
 /* USER CODE BEGIN USART1_IRQn 1 */
 HAL_UART_RxCpltCallback(&huart1);

 /* USER CODE END USART1_IRQn 1 */
}

/**
 * @brief This function handles DMA2 stream2 global interrupt.
 */
void DMA2_Stream2_IRQHandler(void)
{
 /* USER CODE BEGIN DMA2_Stream2_IRQn 0 */

 /* USER CODE END DMA2_Stream2_IRQn 0 */
 HAL_DMA_IRQHandler(&hdma_usart1_rx);
 /* USER CODE BEGIN DMA2_Stream2_IRQn 1 */

 /* USER CODE END DMA2_Stream2_IRQn 1 */
}

/* USER CODE BEGIN 1 */

/* USER CODE END 1 */

Yash JasnaniAuthor

Associate II

Once I reduces the PWM CLK Frequncy by modifing Couter Period to 1000 Ticks and Pules Value to 500. UART can receive data and than Half Pulse Complete Interrupt writes this data to GPIOA->ODR and GPIOB->ODR registor.

Timer Config For 100KHz CLK

/* USER CODE BEGIN Header */
/**
 ******************************************************************************
 * @file : main.c
 * @brief : Main program body
 ******************************************************************************
 * @attention
 *
 * Copyright (c) 2023 STMicroelectronics.
 * All rights reserved.
 *
 * This software is licensed under terms that can be found in the LICENSE file
 * in the root directory of this software component.
 * If no LICENSE file comes with this software, it is provided AS-IS.
 *
 ******************************************************************************
 */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */

/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/
TIM_HandleTypeDef htim4;

UART_HandleTypeDef huart1;
DMA_HandleTypeDef hdma_usart1_rx;

/* USER CODE BEGIN PV */
int16_t buf[4] = { 0xFFFF, 0x8000, 0x0000, 0x7FFF };
uint8_t rx_buf[100] = { 0 };
int i = 0;
/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_TIM4_Init(void);
static void MX_USART1_UART_Init(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

/**
 * @brief The application entry point.
 * @retval int
 */
int main(void)
{
 /* USER CODE BEGIN 1 */

 /* USER CODE END 1 */

 /* MCU Configuration--------------------------------------------------------*/

 /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
 HAL_Init();

 /* USER CODE BEGIN Init */

 /* USER CODE END Init */

 /* Configure the system clock */
 SystemClock_Config();

 /* USER CODE BEGIN SysInit */

 /* USER CODE END SysInit */

 /* Initialize all configured peripherals */
 MX_GPIO_Init();
 MX_DMA_Init();
 MX_TIM4_Init();
 MX_USART1_UART_Init();
 /* USER CODE BEGIN 2 */

	HAL_TIM_PWM_Start_IT(&htim4, TIM_CHANNEL_3);
	HAL_UART_Receive_DMA(&huart1, rx_buf, sizeof(rx_buf));

 /* USER CODE END 2 */

 /* Infinite loop */
 /* USER CODE BEGIN WHILE */
	while (1) {
 /* USER CODE END WHILE */

 /* USER CODE BEGIN 3 */

//		GPIOA->ODR = (uint32_t) (rx_buf[i] & 0x00FF);
//		GPIOB->ODR = (uint32_t) (rx_buf[i + 1] & 0x00FF);
//		i++;
//		if (i == 99)
//			i = 0;
	}
 /* USER CODE END 3 */
}

/**
 * @brief System Clock Configuration
 * @retval None
 */
void SystemClock_Config(void)
{
 RCC_OscInitTypeDef RCC_OscInitStruct = {0};
 RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

 /** Configure the main internal regulator output voltage
 */
 __HAL_RCC_PWR_CLK_ENABLE();
 __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

 /** Initializes the RCC Oscillators according to the specified parameters
 * in the RCC_OscInitTypeDef structure.
 */
 RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
 RCC_OscInitStruct.HSEState = RCC_HSE_ON;
 RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
 RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
 RCC_OscInitStruct.PLL.PLLM = 12;
 RCC_OscInitStruct.PLL.PLLN = 96;
 RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
 RCC_OscInitStruct.PLL.PLLQ = 4;
 if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
 {
 Error_Handler();
 }

 /** Initializes the CPU, AHB and APB buses clocks
 */
 RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
 |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
 RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
 RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
 RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
 RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

 if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_3) != HAL_OK)
 {
 Error_Handler();
 }
}

/**
 * @brief TIM4 Initialization Function
 * @PAram None
 * @retval None
 */
static void MX_TIM4_Init(void)
{

 /* USER CODE BEGIN TIM4_Init 0 */

 /* USER CODE END TIM4_Init 0 */

 TIM_ClockConfigTypeDef sClockSourceConfig = {0};
 TIM_MasterConfigTypeDef sMasterConfig = {0};
 TIM_OC_InitTypeDef sConfigOC = {0};

 /* USER CODE BEGIN TIM4_Init 1 */

 /* USER CODE END TIM4_Init 1 */
 htim4.Instance = TIM4;
 htim4.Init.Prescaler = 0;
 htim4.Init.CounterMode = TIM_COUNTERMODE_UP;
 htim4.Init.Period = 1000-1;
 htim4.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
 htim4.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
 if (HAL_TIM_Base_Init(&htim4) != HAL_OK)
 {
 Error_Handler();
 }
 sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
 if (HAL_TIM_ConfigClockSource(&htim4, &sClockSourceConfig) != HAL_OK)
 {
 Error_Handler();
 }
 if (HAL_TIM_PWM_Init(&htim4) != HAL_OK)
 {
 Error_Handler();
 }
 sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
 sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
 if (HAL_TIMEx_MasterConfigSynchronization(&htim4, &sMasterConfig) != HAL_OK)
 {
 Error_Handler();
 }
 sConfigOC.OCMode = TIM_OCMODE_PWM1;
 sConfigOC.Pulse = 500;
 sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
 sConfigOC.OCFastMode = TIM_OCFAST_ENABLE;
 if (HAL_TIM_PWM_ConfigChannel(&htim4, &sConfigOC, TIM_CHANNEL_3) != HAL_OK)
 {
 Error_Handler();
 }
 /* USER CODE BEGIN TIM4_Init 2 */

 /* USER CODE END TIM4_Init 2 */
 HAL_TIM_MspPostInit(&htim4);

}

/**
 * @brief USART1 Initialization Function
 * @PAram None
 * @retval None
 */
static void MX_USART1_UART_Init(void)
{

 /* USER CODE BEGIN USART1_Init 0 */

 /* USER CODE END USART1_Init 0 */

 /* USER CODE BEGIN USART1_Init 1 */

 /* USER CODE END USART1_Init 1 */
 huart1.Instance = USART1;
 huart1.Init.BaudRate = 115200;
 huart1.Init.WordLength = UART_WORDLENGTH_8B;
 huart1.Init.StopBits = UART_STOPBITS_1;
 huart1.Init.Parity = UART_PARITY_NONE;
 huart1.Init.Mode = UART_MODE_TX_RX;
 huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
 huart1.Init.OverSampling = UART_OVERSAMPLING_16;
 if (HAL_UART_Init(&huart1) != HAL_OK)
 {
 Error_Handler();
 }
 /* USER CODE BEGIN USART1_Init 2 */

 /* USER CODE END USART1_Init 2 */

}

/**
 * Enable DMA controller clock
 */
static void MX_DMA_Init(void)
{

 /* DMA controller clock enable */
 __HAL_RCC_DMA2_CLK_ENABLE();

 /* DMA interrupt init */
 /* DMA2_Stream2_IRQn interrupt configuration */
 HAL_NVIC_SetPriority(DMA2_Stream2_IRQn, 0, 0);
 HAL_NVIC_EnableIRQ(DMA2_Stream2_IRQn);

}

/**
 * @brief GPIO Initialization Function
 * @PAram None
 * @retval None
 */
static void MX_GPIO_Init(void)
{
 GPIO_InitTypeDef GPIO_InitStruct = {0};
/* USER CODE BEGIN MX_GPIO_Init_1 */
/* USER CODE END MX_GPIO_Init_1 */

 /* GPIO Ports Clock Enable */
 __HAL_RCC_GPIOC_CLK_ENABLE();
 __HAL_RCC_GPIOH_CLK_ENABLE();
 __HAL_RCC_GPIOA_CLK_ENABLE();
 __HAL_RCC_GPIOB_CLK_ENABLE();

 /*Configure GPIO pin Output Level */
 HAL_GPIO_WritePin(GPIOC, GPIO_PIN_13, GPIO_PIN_RESET);

 /*Configure GPIO pin Output Level */
 HAL_GPIO_WritePin(GPIOA, GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_4|GPIO_PIN_5
 |GPIO_PIN_6|GPIO_PIN_7, GPIO_PIN_RESET);

 /*Configure GPIO pin Output Level */
 HAL_GPIO_WritePin(GPIOB, GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3
 |GPIO_PIN_4|GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_7, GPIO_PIN_RESET);

 /*Configure GPIO pin : PC13 */
 GPIO_InitStruct.Pin = GPIO_PIN_13;
 GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
 GPIO_InitStruct.Pull = GPIO_NOPULL;
 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
 HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);

 /*Configure GPIO pins : PA0 PA1 PA4 PA5
 PA6 PA7 */
 GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_4|GPIO_PIN_5
 |GPIO_PIN_6|GPIO_PIN_7;
 GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
 GPIO_InitStruct.Pull = GPIO_PULLDOWN;
 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
 HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

 /*Configure GPIO pins : PB0 PB1 PB2 PB3
 PB4 PB5 PB6 PB7 */
 GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3
 |GPIO_PIN_4|GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_7;
 GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
 GPIO_InitStruct.Pull = GPIO_PULLDOWN;
 GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
 HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}

/* USER CODE BEGIN 4 */
//Whem using received data from UART
void HAL_TIM_PWM_PulseFinishedHalfCpltCallback(TIM_HandleTypeDef *htim) {
	GPIOA->ODR = (uint32_t) (rx_buf[i] & 0x00FF);
	GPIOB->ODR = (uint32_t) ((rx_buf[i + 1]) & 0x00FF);
	i++;
	if (i == 99)
		i = 0;
}
//only to check Whether connections are ok!
//void HAL_TIM_PWM_PulseFinishedHalfCpltCallback(TIM_HandleTypeDef *htim) {
//	GPIOA->ODR = (uint32_t) (buf[i] & 0x00FF);
//	GPIOB->ODR = (uint32_t) ((buf[i] >> 8) & 0x00FF);
//	i++;
//	if (i == 4)
//		i = 0;
//}
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart) {
	HAL_UART_Receive_DMA(&huart1, rx_buf, sizeof(rx_buf));
}
/* USER CODE END 4 */

/**
 * @brief This function is executed in case of error occurrence.
 * @retval None
 */
void Error_Handler(void)
{
 /* USER CODE BEGIN Error_Handler_Debug */
	/* User can add his own implementation to report the HAL error return state */
	__disable_irq();
	while (1) {
	}
 /* USER CODE END Error_Handler_Debug */
}

#ifdef USE_FULL_ASSERT
/**
 * @brief Reports the name of the source file and the source line number
 * where the assert_param error has occurred.
 * @PAram file: pointer to the source file name
 * @PAram line: assert_param error line source number
 * @retval None
 */
void assert_failed(uint8_t *file, uint32_t line)
{
 /* USER CODE BEGIN 6 */
 /* User can add his own implementation to report the file name and line number,
 ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
 /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */

Bob S

Super User

You are trying to generate a 12.5 MHz clock (via TIM PWM) and then write data to your DAC at that same 12.5 MHz rate? And have that data come from a UART?????????

Even ignoring the issue of the timer interrupt starving the CPU, you have a basic synchronization issue. How can you guarantee that you will always receive data from the UART before you need to write it to the DAC (i.e. don't underflow your buffer)? And how do you guarantee that you never get too much data from the UART (i.e. don't overflow your buffer or drop data)?

Yash JasnaniAuthor

Associate II

@Bob S wrote:
You are trying to generate a 12.5 MHz clock (via TIM PWM) and then write data to your DAC at that same 12.5 MHz rate?
Yes
And have that data come from a UART?????????
Yes
Even ignoring the issue of the timer interrupt starving the CPU, you have a basic synchronization issue. How can you guarantee that you will always receive data from the UART before you need to write it to the DAC (i.e. don't underflow your buffer)? And how do you guarantee that you never get too much data from the UART (i.e. don't overflow your buffer or drop data)?
I haven't thought about these issues. Sugguest me what can I do from my side to solve these problem and get the DAC working and fulfill my requirement.

Bob S

Super User

I can't/won't solve your system design issues for you. But here are some questions you need to consider:

If you write 2 bytes to the DAC at a 12.5 MHz rate, how many bytes per second is that? How many bits per second would that require from your UART (for UART data, each "byte" takes 10 bit times to send)? Is your UART capable of receiving data at that rate?
Do you really need to update the DAC at that rate?
Does your data source (the other end of the UART connection) always provide a constant stream of data? Or is the data "bursty" (gaps between some of the data).

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