STM32WLE5 SubGhz Debug - Alternate functions

[viola]

Hi ,

in the Datasheet there are few interfaces which are marked as "alternate functions" for DEBUG_RF or DEBUG_SUBGHZSPI.  ( Table 20 in the Datasheet)

But , I didnt find any info regarding what can I use those function for ? 

for example - Can i access this SPI from external pins ? 

is there additional Info regarding those debug capabilities and what each signal is used for ?

Thanks

Viola

[STTwo-32]

Hello @viola 

The user does not interact with the sub-GHz radio through a set of memory mapped registers. Rather, a dedicated internal SPI interface (the SUBGHZSPI) is used to communicate with the RF subsystem. So, when issues arise during firmware development. The user will need to debug the system. So, ST mapped some internal signals to GPIOs to facilitate the debug by just configuring those GPIOs to the dedicated Alternate function. Like this, you will be able to view some signals in real time throw an oscilloscope for example.  Like that, debug will be as easy as possible. 

Best Regards.

STTwo-32

[viola]

Hello STTwo-32 

In order to debug the internal sub-GHz radio , the only option is to use the SUBGHZSPI ? or , for example I can access the internal sub-GHz radio through one of the UART interfaces I use ?

Thank you,

Viola

[STTwo-32]

Hello @viola 

On the STM32WL MCUs. The SUBGHZ module is controled using the SUBGHZSPI. Thats why the SUBGHZSPI signals are mapped to some GPIOs. So you can visualise the state of this signal (NSS, MOSI, MISO,...) in real time. So, it is not exactly a debug but is signal an trame visualisation that will help you to know what is exactly happening will debuging your code (what the MCU send to the SUBGHZ module and what it receive...).

Best Regards.

STTwo-32 

[viola]

so I cannot issue SPI transaction when the SUBGHZSPI siganls are mapped to the GPIOs ? 

I can only probe the SPI signals ?

[STTwo-32 · Accepted solution]

Exactly.

Best Regards.

STTwo-32