STM32L0 Replace all HSI48 with HSI16 ???

Dvorak.Peter · ‎2016-10-13

Posted on October 13, 2016 at 14:38

A quick scan of my STM32Cube_FW_L0_V1.7.0 directory shows:

Search ''HSI48ON'' (2894 hits in 1042 files)

C:\Users\PD\STM32Cube\Repository\STM32Cube_FW_L0_V1.7.0\Drivers\CMSIS\Device\ST\STM32L0xx\Include\stm32l052xx.h (5 hits)

Line 3609: &sharpdefine RCC_CRRCR_HSI48ON_Pos (0U)

Line 3610: &sharpdefine RCC_CRRCR_HSI48ON_Msk (0x1U << RCC_CRRCR_HSI48ON_Pos) /*!< 0x00000001 */

Line 3611: &sharpdefine RCC_CRRCR_HSI48ON RCC_CRRCR_HSI48ON_Msk /*!< HSI 48MHz clock enable */

...

It seems that the STM32L0 sample code was copied from a different family.

Is it safe to replace all 2894 typos automatically ?

Is this just a cosmetic problem or a sign of poor quality control ?

Can the STM32L0 HAL and Low-layer drivers be trusted ?

Peter

#stm32l0-hsi48

Nesrine M_O · ‎2016-10-13

Posted on October 13, 2016 at 15:45

Hi Peter,

This is not a bug: in fact the STM32L0x2 and STM32L0x3 devices embed an internal 48 MHz RC oscillator (HSII48) dedicated to provide a high precision clock to USB and random number generator (RNG)

Please refer to Reset and clock control (RCC) section in the RM0376 Reference manual (for stm32l052xx device).

-Syrine-

Dvorak.Peter · ‎2016-10-18

Posted on October 18, 2016 at 15:58

Hi Syrine,

Thank you for pointing me to the RM0376 Reference manual (for stm32l052xx device).

This reference clarified the nature of the problem.

The confusion started with the STM32L011K4-Nucleo example for ADC in STM32Cube_FW_L0_V1.7.0.

There in system_stm32l0xx.c SystemInit is a line of code :

RCC->CRRCR &= (uint32_t)0xFFFFFFFE; /*!< Reset HSI48ON bit */

The STM32L0x1 reference manual RM0377 does not mention anything about CRRCR register or HSI48ON bit.

The sample code should not clean compile for STM32L011K4 target.

Peter