STPM34 weird values reading his registers

[SteRogge]

Hi,

I'm debugging a board with two STMP34 used to read voltage and current from L1 - L2 and L3 of a threephase system. 

The current signals comes from three different TA devices.

The issue is: sometimes, reading a block of registers using the Metro_HAL_Stpm_Read function, I have strange values of these, below you can find some screenshots of IAR debugger and some others coming from Saleae used to capture these weird values.

This phenomenon happens only in some boards, even if the hardware seems to be OK.

Here you can see the function I use to read the STPM34 device...

Here you can see the weird values I have reading it....

Here a series of screenshots coming from the Saleae attached on SCS, SYN , EN and SPI signals of the second STPM34 (used to read L2 and L3 phases).....

And here some screenshots of the schematic....

Thanks in advance for your support.

Regards

Stefano