STM32C071FBP6 Pin muxing issue

[Sumanth_Veeyes]

I am using STM32C071FBP6N MCU TSSOP 20 pin package for one of our project.
I am observing Pin_20 is muxed with lot of other pins like PB3/PB4/PB5/PB6. if i select PB3 as GPIO_Output using STM32CubeMx and generated a code. If i try to toggle the pin but its not working at all, none of the peripheral on that pin for PB3 is working. But if i select PB6 as GPIO_Output i can able to toggle or modify.
This issue is not only with Pin_20, same with Pin_1 also which shares with PB7/PB8, only PB7 is working.

I have tried with multiple chips what could be wrong in this scenario??

[Ghofrane GSOURI]

Hello @Sumanth_Veeyes 

Could you please provide your IOC in order to check your configuration and code .

I will be waiting for your feedback.

THX

Ghofrane

[TDK]

CubeMX assumes SECURE_MUXING_EN = 0 when it generates code, which is not the default.

Solved: STM32C092FCP6 SPI, SCK Pin remapping by CubeMX - STMicroelectronics Community

You can only use one muxed pin at a time if SECURE_MUXING_EN is enabled. Probably the settings in SYSCFG_CFGR3 are not being set up correctly by CubeMX. PB3 and PB7 are enabled by default which explains why they are working.

[Sumanth_Veeyes]

Here is the IOC generated using CubeMx for your reference

[Sumanth_Veeyes]

Without using CubeMX how can i hardcode SYS_CFG3 to use PB3??

[Ghofrane GSOURI · Accepted solution]

Hello @Sumanth_Veeyes 

By checking the Firmware , you need to call the following HAL function 

  * @brief  Set Pin Binding
  * @param  pin_binding specifies which pin will bind a specific GPIO
  *         for each die package
  *         This parameter can be a value of @ref HAL_BIND_CFG
  * @retval None
  */
void HAL_SYSCFG_SetPinBinding(uint32_t pin_binding)
{
  /* Check the parameter */
  assert_param(IS_HAL_SYSCFG_PINBINDING(pin_binding));
  LL_SYSCFG_ConfigPinMux(pin_binding);
}

in your case : the parameter will be 

#define HAL_BIND_TSSOP20_PIN20_PB3     LL_PINMUX_TSSOP20_PIN20_PB3    /*!< STM32C071 TSSOP20 package, Pin20 assigned to GPIO PB3 */

So add this call in your code 

uint32_t  pin_binding = HAL_BIND_TSSOP20_PIN20_PB3;
HAL_SYSCFG_SetPinBinding(pin_binding );

I will be waiting for your feedback.

THX

Ghofrane

[Sumanth_Veeyes]

Thank you Ghofrane,
for quick reply and helping in resolving the issue!!.

[Ghofrane GSOURI]

Hello @Sumanth_Veeyes @TDK 

I have created ticket #0061882 to address the missing pin binding configuration generation in CubeMX.

Thank you all for your cooperation.

THX

Ghofrane