SLUSDT5B September 2019 – October 2023 BQ75614-Q1
PRODUCTION DATA
A COMM CLEAR is sent on the RX pin of the device. I RX cannot be disabled and a COMM CLEAR can be sent at any time regardless of the TX status. Ensure that the COMM CLEAR does not exceed the maximum value of tUART(CLR) bit periods, as this may result in recognition of other communication pings.
Use the COMM CLEAR command to clear the receiver and instruct the UART engine to look for a new start of frame. The next byte following the COMM CLEAR is always considered a start-of-frame byte. When detected, a COMM CLEAR sets the FAULT_COMM1[COMMCLR_DET] flag. The host must wait at least tUART(RXMIN) after the COMM CLEAR to start sending a new frame. It should be noted that in addition to the [COMMCLR_DET] flag, the FAULT_COMM1[STOP_DET] flag is also set because the COMM CLEAR timing violates the typical byte timing and the STOP bit is seen as 0.
A SLEEPtoACTIVE ping also clears the UART receiver. This ping sets the [COMMCLR_DET] flag when transiting from SLEEP to ACTIVE mode. If this ping is sent during ACTIVE mode, the [COMMCLR_DET] and [STOP_DET] flags are set.