SPI Communication for Multi-slave selection

[satvenmechatron]

Hi NXP Team,

We are working on BMS. So, we integrated NXP S32K144 with one FRDM33772 Board, and we are able to receive all the Cell data. Here we need to integrate 6 FRDM33772 Boards with S32K144 Board. But in S32K144 MBD Toolbox, LPSPI_Config Block is limited to 4 specific Chip Selection Pins.

How can 6 FRDM33772 Boards configure with S32K144 SPI Communication and with customized chip selection I/Os? 

Thanks & regards,

Satven Mechatronics Team

[mariuslucianand]

Hello @satvenmechatron ,

If my understanding is correct, you want to connect the S32K144 with 6 battery packs using the MC33772B SPI. In this case, if you want to use the SPI, there are a couple of issues:

1. our toolbox is not supporting multiple SPI communications for the MC3377xB.

2. If the battery packs are connected in series, then there is an issue with the electrical levels between the packs (the GND of one pack becomes positive for the other pack) and this requires isolating all the communication lines and chip-select.

The solution NXP proposes is to use the TPL approach. Basically, you have to use the MC33664 as isolation but you can connect up to 15 battery cell controllers. See the article below:

https://community.nxp.com/t5/NXP-Model-Based-Design-Tools/BMS-amp-MBDT-MC33771B-MC33772B-TPL-communi... 

Hope this helps,
Marius