SLUSDQ4 April 2019 BQ79606A-Q1
The UART interface requires the that TX and RX are pulled-up to VIO through a 10-kΩ to 100-kΩ resistor. Do not leave TX and RX unconnected. The TX must be pulled high to prevent triggering an invalid communications frame during the idle state when TX is high. When using a serial cable to connect to the host controller, connect the TX pull up on the host side and the RX pull up on the BQ79606A-Q1side.