STM32Cube FW_F1 V1.8.0 package breaks HAL time source init

Posted on 2019-09-042019-09-04 by Ivan

As a hobby I’m working on a growbox controller which based on stm32 MCU. Yesterday I got STM32Cube MCU package update, as many times before I just upgraded package and project to latest version, as result firmware started to stuck in assert_failed().

It happens during call of SystemClock_Config() (defined in main.c) which in turn calls HAL_RCC_ClockConfig(), which in turn calls HAL_InitTick(uwTickPrio) at Drivers/STM32F1xx_HAL_Driver/Src/stm32f1xx_hal_rcc.c:947:

...
  /* Update the SystemCoreClock global variable */
  SystemCoreClock = HAL_RCC_GetSysClockFreq() &gt;&gt; AHBPrescTable[(RCC-&gt;CFGR &amp; RCC_CFGR_HPRE) &gt;&gt; RCC_CFGR_HPRE_Pos];
 
  /* Configure the source of time base considering new system clocks settings*/
  HAL_InitTick(uwTickPrio);
 
  return HAL_OK;
}

When it happens uwTickPrio still have invalid interrupt priority, which is defined in Drivers/STM32F1xx_HAL_Driver/Src/stm32f1xx_hal.c:80:

...
/** @defgroup HAL_Private_Variables HAL Private Variables
  * @{
  */
__IO uint32_t uwTick;
uint32_t uwTickPrio   = (1UL &lt;&lt; __NVIC_PRIO_BITS); /* Invalid PRIO */
HAL_TickFreqTypeDef uwTickFreq = HAL_TICK_FREQ_DEFAULT;  /* 1KHz */
...

Only one place where uwTickPrio can be updated is ./Drivers/STM32F1xx_HAL_Driver/Src/stm32f1xx_hal.c:234:

__weak HAL_StatusTypeDef HAL_InitTick(uint32_t TickPriority)
{
  /* Configure the SysTick to have interrupt in 1ms time basis*/
  if (HAL_SYSTICK_Config(SystemCoreClock / (1000U / uwTickFreq)) &gt; 0U)
  {
    return HAL_ERROR;
  }
 
  /* Configure the SysTick IRQ priority */
  if (TickPriority &lt; (1UL &lt;&lt; __NVIC_PRIO_BITS))
  {
    HAL_NVIC_SetPriority(SysTick_IRQn, TickPriority, 0U);
    uwTickPrio = TickPriority;
  }
  else
  {
    return HAL_ERROR;
  }
 
  /* Return function status */
  return HAL_OK;
}

But this function is redefined in ./Core/Src/stm32f1xx_hal_timebase_tim.c:42:

HAL_StatusTypeDef HAL_InitTick(uint32_t TickPriority)
{
  RCC_ClkInitTypeDef    clkconfig;
  uint32_t              uwTimclock = 0;
  uint32_t              uwPrescalerValue = 0;
  uint32_t              pFLatency;
 
  /*Configure the TIM4 IRQ priority */
  HAL_NVIC_SetPriority(TIM4_IRQn, TickPriority ,0);
 
...

And doesn’t contain proper uwTickPrio initialization, as result it’s called with invalid TickPriority and fails into assert_failed() during HAL_NVIC_SetPriority(TIM4_IRQn, TickPriority ,0) call.

STM32 performance test or how fast you can serve input signal

Posted on 2014-03-312014-04-01 by Ivan

Finally, i decided to try stm32, before i wrote firmwares only for AVR mega family (from now, when i say AVR MCU, i mean AVR mega family MCU), and was scared by tonns of code that you need for simply led blinking on STM32 MCU.
Now i can say, that programming of STM32 not so hard as it looks first time. After i understand logical structure of MCU core and how it work, it become easy.
OK, it was prelude.

Every time when i see comparison between AVR and STM32/STM8 MCU’s i faced with next arguments:
STM MCU’s have lower price, when they have more RAM, FLASH, GPIO pins and work frequency. Looks sweet. Today i want to tell the story about work frequency.

More than the operating frequency of the MCU, the faster it can handle events. STM32 MCU’s have maximum work frequency more than 20MHz (72MHz for STM32F103 that i have), when AVR MCU’s have only 20MHz. Is 72MHz a lot of or not? Two week ago i wanted to know, is it enough ~200MHz of STM32F4 to handle 10MSPS ADC on not? Two weeks ago i think ‘may be’. Now i think ‘not enought’.

Last Friday evening i blow the dust from oscilloscope and made little research.
My basic code poll pin, by software, configured for input and set same signal on output pin, the code is there:

while(1) {
         if( GPIOB->IDR & GPIO_IDR_IDR10 ) {
                        GPIOB->BSRR = GPIO_BSRR_BS8;
         } else {
                        GPIOB->BSRR = GPIO_BSRR_BR8;
         }
}

How many time MCU need to set same level on GPIO pin as on input pin? May be 140nS (near 10 clocks on 72MHz) will enought?

Nope. 480ns. It near 34 cycles. The period of 480ns has frequency of 2MHz, may be i forgot to change speed of gpio port?

Nope. May be i forgot to switch on external quartz or forgot to configure PLL?

Nope. Hmm, may be optimization can help? Let’s try to switch on -O3:

Much better, 170 ns. MCU need near 12 cycles, to detect signal and change state of one GPIO speed. Do not forget, MCU just pooling one pin and change state of another, it do not do valuable work.Okay, but what the maximum speed you can get, if you will just change the state of GPIO pin?
Is it possible to hit theoretical maximum of 50MHz (max clock speed of GPIO ports on STM32F103):

Just 6MHz. Let me switch on optimization for you:

Looks like there only 36MHz, let’s look on the code:

I can’t see why they can’t reach 50MHz. If you look on disassembler view, you can see, that MCU just store different values on constant address.
In fairness i must to say, if you set cursors on oscilloscope in different manner, you can achieve 50MHz:

It is hard to say what way of measurement is wrong, i think the second, because first time it is easy to see time of 2 periods. Without a doubt, the second way STM advertising department would have liked more.
BONUS:
A picture where is while cycle occurs:

IvanBayan

Tag: stm32

STM32Cube FW_F1 V1.8.0 package breaks HAL time source init

STM32 performance test or how fast you can serve input signal