ZHCSTD7A December 2021 – November 2023 BQ79631-Q1
PRODUCTION DATA
A ping is a specific high-low-high signal to the RX pin of the device. Ping is used on the base device as only the base device is connected to the host which the UART RX is accessible. The device detects different low times of the ping signal to differentiate the different ping signals.
The communication pings are referring to the WAKE ping, SLEEPtoACTIVE ping, SHUTDOWN ping, and HW_RESET ping. These pings instruct the device to a specific power mode when normal communication is not available. By definition, a COMM CLEAR signal on the RX pin is a form of a ping. Because a COMM_CLR is to clear the UART engine, this signal is covered in Section 8.3.5.1.1.1.