STM32L4S5QI - Is the choice of bootloader peripheral dependent on the package?

[MCeni.1]

We're designing a PCB with STM32L4S5QI and decided to use UFBGA132 package. Having a bootloader access is an absolute must, and preferably we want to use USB or UART for simplicity. However, a table I found in the datasheet suggests that with the UFBGA132 package, the bootloader can only use SPI. I didn't find this limitation mentioned anywhere else in the datasheet, the reference manual or in the AN2606 (bootloader app note).

So does the choice of package really limit the bootloader peripherals, or is it possible to use UART for bootloader with UFBGA132 variant of STM32L4S5QI?

Thanks,

Michal

[waclawek.jan]

That's a bizarre and most probably incorrect line in Table 2 of DS12024 Rev 4.

@Imen DAHMEN​  , can you please check this line and perhaps confirm that all interfaces with available pins are available for the given package.

Thanks,

JW

[MCeni.1]

Hi Jan,

Thanks for your reply. I too think that this is incorrect information in the table, but I would like to get a confirmation from someone from ST to be absolutely sure before committing the design to layout and manufacturing.

@Imen DAHMEN (ST Employee)

Hello Imen, can you please comment on the above?

Thanks,

Michal

[Imen.D]

Hello,

You are right ! Looking at the table, this means that only the pins of the SPI exist, which is not normal for a BGA132 package: If the pins exist, the bootloader must work.

I will raise this internally for fix.

Best Regards,

Imen

[waclawek.jan]

Thanks, Imen.

Jan