STM32F4 Timing Problem with systick after switching IDE (coocox to TrueStudio) - ide

Question

I am working on a weird problem: As a part of my project, I migrated a firmware from CooCox to TrueStudio. Both, CooCox and TrueStudio automatically create some standard files while creating a project for a specific Microcontroller. The Microcontroller used here is the STM32F407VGT6. I am using ms - delay and s - delay which are derived from the µs - Delay function I will show you.
*edit2: I should mention, that the original project is a pure C project. I am trying to make the Project a C++/C project in TrueStudio.
What I will try now is to migrate the firmware into a TrueStudio pure C project and see if the problem still exists.
I will inform you about the results
**Results: The problem is actually gone now in the pure C Project, but I would really like to implement classes etc using C++. Any ideas how to solve this?
**
*
The initializing systick code is (HCLK Frequency = 168MHz).
*edit1: the HCLK Frequency equals the SYSCLK *
void systick_init(void){
RCC_ClocksTypeDef RCC_Clocks;
Systick_Delay=0;
RCC_GetClocksFreq(&RCC_Clocks);
SysTick_Config((RCC_Clocks.HCLK_Frequency / 1000000) - 1);
}
The function for the 1µs Delay looks like this:
void delay_us(volatile uint32_t delay)
{
Systick_Delay = delay;
while(Systick_Delay != 0);
}
The Systick Handler contains the following Code:
void SysTick_Handler(void)
{
// Tick für Delay
if(Systick_Delay != 0x00)
{
Systick_Delay--;
}
}
When I create a .hex file to flash the µC with using Coocox, the timing function works (with some minor accuracy mistakes that don't bother me).
When I create the .hex file with TrueStudio, the delays have massive inaccuracys. For example, a delay of 500ms becomes a delay of roughly 2s.
Since the Code is written dependant on the actual HCLK_Frequency, I can't understand the mistake and in my understanding, even if the HCLK should differ, the 1µs Delay should still take about 1µs.
My next step will be comparing the automatically created system files, but maybe anyone has a different approach / another idea?
*edit 3: I normally include my systick - header with the command ' extern "C" '. So my systick source file is a .c file. When I rename the file to systick.cpp, and I include the header without 'extern "C"', the delay function does not work at all. Maybe, that helps with the solution?
*

Answer 1

You are either running off a different clock or have different PLL settings. Looks like your clock speed is 1/4 of what you had before.
The basic startup code provided does not always set the maximum speed for the board. Have a look in some of the examples in the stm32cube.zip code. You will find some System Clock Configuration code for your board which will select the correct clock and pll settings. (this will be in your code somewhere as well).
Look in main.c under stm32cubef4/projects/STM32F4-Discovery\Demonstrations\src.
You will find the following code which sets up the clock:
/**
* #brief System Clock Configuration
* The system Clock is configured as follow :
* System Clock source = PLL (HSE)
* SYSCLK(Hz) = 168000000
* HCLK(Hz) = 168000000
* AHB Prescaler = 1
* APB1 Prescaler = 4
* APB2 Prescaler = 2
* HSE Frequency(Hz) = 8000000
* PLL_M = 8
* PLL_N = 336
* PLL_P = 2
* PLL_Q = 7
* VDD(V) = 3.3
* Main regulator output voltage = Scale1 mode
* Flash Latency(WS) = 5
* #param None
* #retval None
*/
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_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_HCLK | 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);
/* STM32F405x/407x/415x/417x Revision Z devices: prefetch is supported */
if (HAL_GetREVID() == 0x1001)
{
/* Enable the Flash prefetch */
__HAL_FLASH_PREFETCH_BUFFER_ENABLE();
}
}

Answer 2

I found the solution now!
For anyone having similar problems:
You need to declare the SysTick_Handler function as
extern "C" void SysTick_Handler(void)
{
//Tick für Delay
if(Systick_Delay != 0x00)
{
Systick_Delay--;
}
}
Now it is working like it is supposed to do.