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BQ27621-G1: Unable to enter CFG_UPDATE mode

Part Number: BQ27621-G1


I am trying to set the battery chemistry and having some issues entering cfg_update mode. 

First I do a hard reset upon start by using the Reset() subcommand:

Write(0x0, 0x41)

After which the ITPOR bit is set:

Flags is 0x21

I also checked the control status and saw that the gauge is unsealed:

Control status is 0x4.

However, when I send the cfg update subcommand, I do not see a change in the Flags() register, even after polling for more than 1 second. 

I am doing: Write(0x0, 0x13), and the flags register stays the same as above. 

I have tried out other subcommands which seem to be working properly, including set_hibernate, clear_hibernate, shutdown_enable, and toggle_powermin. 

Please let me know if I am missing something or any next steps to debug. Thanks!