Want learn more about multi-bonding and STM32CubeMX "extended mode"

[wb0gaz]

I need to learn more (detail) about STMCubeMX  "extended mode" and small-pincount multi-bonded MCUs (this posting label specifies STM32C0 series which is what I'm currently working with.)

STM32CubeMX UM1718 section 4.5.8 describes extended mode (I encountered when exploring this option while using STM32CubeMX with a new project), but other than cautions (that an option byte is required and that improper use can affect power consumption etc) I could find no further ("how it works") detail there.

HAL_SYSCONFIG_SetBinBinding doesn't provide a suitable solution (concurrent access to a single physical pin by more than one possible peripheral.)

Any recommendations on where (=application note?) I can proceed to learn about multi-bonding implementation and limitations for these small-packaged MCU products?

Thanks!

[TDK · Accepted solution]

The reference manual is the primary reference source for how the chip operates. It lists all of the option bytes and what they do.

https://www.st.com/resource/en/reference_manual/rm0490-stm32c0-series-advanced-armbased-32bit-mcus-stmicroelectronics.pdf

"Extended mode" seems to be CubeMX name for SECURE_MUXING_EN=0. You have to ensure no conflicts on a pin and SYSCFG_CFGR3 settings are ignored. CubeMX won't modify option bytes. You have to do that yourself with STM32CubeProgrammer or by code.

[wb0gaz]

Thank you - SECURE_MUXING_EN=0 provides the needed clue!

Dave