57.7.9.8.2 Beta1 Tx/Rx
Beta1 is the period immediately following the end of a packet cycle (see the above figure). A node attempting to transmit monitors the state of the channel, and if it detects no transmission during the Beta1 period, it determines the channel to be idle.
The Beta1 value is different depending on the previous packet type (received packet or transmitted packet).
Beta1Rx and Beta1Tx length can be configured respectively through the USART LON Beta1 Rx register (FLEX_US_LONB1RX) and the USART LON Beta1 Tx register (FLEX_US_LONB1TX). Note that a length of ‘0’ is not allowed.