BQ79616-Q1: About NFAULT during SHUTDOWN mode transition

Yoshihiro,

Shutting the device down resets the UART engine, causing FAULT_COMM1[COMMCLR_DET] to be set. However, the NFAULT output is invalid once you have sent the device the shutdown command.

Regards,

Ben

Yoshihiro,

You can mask faults using the FAUL_MSK1 and FAULT_MSK2 registers and can mask all of FAULT_COMM1 with FAULT_MSK2[MSK_COMM1]. You can try setting this bit before sending the shutdown command. If that doesn't work you could try masking all faults by setting DEV_CONF[NFAULT_EN] = 0 before you shutdown. 

Regards,

Ben 

Yoshihiro,

If you disabled NFAULT using DEV_CONF[NFAULT_EN] = 0 before sending the shutdown command and NFAULT is still toggling when you shutdown, it is likely that this brief toggle will always occur. Remember, the output NFAULT is invalid once you have sent the shutdown command, so you must ignore it.

Regards,

Ben