The CAN bus has two states during powered operation of the device: dominant and recessive. A dominant bus state is when the bus is driven differentially, corresponding to a logic low on the TXD and RXD terminal. A recessive bus state is when the bus is biased to V_CC / 2 via the high-resistance internal input resistors R_IN of the receiver, corresponding to a logic high on the TXD and RXD terminals.

Figure 9-2 Bus States (Physical Bit Representation)

Figure 9-3 Bias Unit (Recessive Common Mode Bias) and Receiver