STM32MP157 and LPDDR3 unused MPU pin consideration

[Badzonor]

Hello,

I designed custom board with STM32MP157 and LPDDR3 memory. Due to PCB manufacture restrictions I needed to connect to ground unused signal called DDR_ATO. I want to know if this is a problem, because if it is the case I can just remove 1 ball from the IC and solder it like that, but maybe it is not necessary?

 

Thank you, Dominik.

[PatrickF]

HI @Badzonor 

We did not recommend to connect VSS to DDR_ATO ball.

DDR_ATO pin should be left open or connected to a test point.

Nevertheless, as a temporary workaround to start playing with your board, and until PCB is fixed, you could probably do it as it is mention that the pin will output '0' when not enabled.

 

Regards