I have fixed it now though - basically you need to set the core clock up properly in uVision 5. In earlier versions (up to 5.10 or so) you used to be able to do this in system_stm32f4xx.c with PLL_M and PLL_Q #defines (8 and 7 respectively) - however in later versions (I am using v5.15) it seems this has been taken away. You now have to set the clock up with something like:

/* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 clocks dividers */ RCC_ClkInitStruct.ClockType = 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_DIV4; RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2; HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5); }

Which seems to work for me to set the SystemCoreClock running aty 168MHz (which is what it should be).

Hope this helps - and if there is an easier way to do this I would be very glad to hear it!

Regards,

Alex

I have fixed it now though - basically you need to set the core clock up properly in uVision 5. In earlier versions (up to 5.10 or so) you used to be able to do this in system_stm32f4xx.c with PLL_M and PLL_Q #defines (8 and 7 respectively) - however in later versions (I am using v5.15) it seems this has been taken away. You now have to set the clock up with something like:

void SystemClock_Config(void) 
{
  RCC_OscInitTypeDef RCC_OscInitStruct;
  RCC_ClkInitTypeDef RCC_ClkInitStruct;

  /* 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 (see datasheet). */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  /* Enable HSE Oscillator and activate PLL with HSE as source */
  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 = 8;
  RCC_OscInitStruct.PLL.PLLN = 336;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 7;
  HAL_RCC_OscConfig(&RCC_OscInitStruct);

  /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2
     clocks dividers */
  RCC_ClkInitStruct.ClockType = 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_DIV4;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;
  HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5);
}

Which seems to work for me to set the SystemCoreClock running at 168MHz (which is what it should be).

Hope this helps - and if there is an easier way to do this I would be very glad to hear it!