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L9963E BMS Eval Board SPI data on the bus

Associate II


I am trying to communicate with BMS IC on our developed board and I donot see the communication happening with BMS IC despite of following all the instructions 

I have a L9963E BMS Eval board for reference,

I have tapped out the SPI frames on the bus to see the data

I could see for the 5 byte of frame data 4 bytes are going first and 2 byte is going after a delay of around 2.2 us



when I have fed the SPI  API spi_lld_exchange with 5 bytes the data goes out in one after the other continously

Is there any specific reason why the data is send in this way?

I do not see any specific section mentioning any where in L9963E data sheet regarding this?

Kindly let me know what could be the reason for this do I need to send the data in this way?

Also I could see the clock frequency is varying in between 8MHz and 12MHz if see the clock in the image it is not pulsated at same frequency



Erwan YVIN
ST Employee

Hello ,

sorry for the delay.

Did you solve your issue?

Do you RLA drivers SPI ?

            Best regards



did you solved that issue .

How you developed that spi communication from externel mcu ?

ST Employee

if you are using an SPC5 microcontroller you can refer to the BMS example in AutoDevKit by importing existing example. You can then compare with your code.