Posted by rrom on 2017-08-08 11:32

It will appear that your SystemClock_Config function with these PLL parameters does not match the System Clock of the STM32L4xx family.
What version of CubeMX do you use?

The L4 operate at the SYSCLK max frequency of 80MHz.
PLL / M = 16 and PLL configurations N = 336 are not allowed.
The maximum permissible values are PLL / M = 8 and PPL N = 86.
Please review the Reference Manual or into CubeMX Clock Configurator Tab.

I think that your function is more like that of a family STM32F4 or F7 and in these conditions

Oscillator Source HSI (which is the internal Oscillator 16MHz)
One would get for a F4 or F7.
SYSCLK (Hz) = HSI / M * N / P = 16000000/16 * 336 / 2 = 84MHz

Regards

Posted by sachingole on 2017-08-08 18:00

Thank you for reply. I realised that and changed as per below. Only one thing I would like clarify from you.
HSI on L4 also give 16MHz by default, right ?

/* system clock set to max 80 MHz */
static void SystemClock_Config(void)
{
RCC_ClkInitTypeDef RCC_ClkInitStruct;
RCC_OscInitTypeDef RCC_OscInitStruct;

/*Enable Power Control clock*/
__HAL_RCC_PWR_CLK_ENABLE();

/*The voltage scaling allows optimizing the power consumption when the device is
clocked below the maximum system frequency, to update the voltage scaling value
regarding system frequency refer to product datasheet.*/
__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);

/*Enable HSI Oscillator and activate PLL with HSI as source*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSICalibrationValue = 0x10;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
RCC_OscInitStruct.PLL.PLLM = 1;
RCC_OscInitStruct.PLL.PLLN = 10;
RCC_OscInitStruct.PLL.PLLR = 2;
if(HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/*Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2
clocks dividers*/
RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | 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_2) != HAL_OK)
{
Error_Handler();
}
}