BQ27Z561-R2: How to change the Authentication Key?

Hello Sir:

I am using BQ27Z561-R2 but I cannot change the Authentication Key.

In TRM section 13.8.20, 128-bit key should be written to MACData().

But SHA-256 need 256bit. I cannot understand this step.

Another question is about the timming.

If my target Key is 00112233445566778899AABBCCDDEEFF00112233445566778899AABBCCDDEEFF.

After UNSEAL_FULL_ACCESS, which operation is correct?

A. Write 3700 to 3E, wait some(How long?) time and then write 00112233445566778899AABBCCDDEEFF00112233445566778899AABBCCDDEEFF 0F24 to 40.

B. Write 3700 00112233445566778899AABBCCDDEEFF00112233445566778899AABBCCDDEEFF 0F24 to 3E directly

Please kindly provide the recommendations for us.

Thanks a lot.

Star Xu：

您好，请参考BQ27Z561的TRM 8.2 SHA-256 Authentication

https://www.ti.com/lit/ug/sluubo7/sluubo7.pdf