This is the medium level of power saving mode of the device. The WUF receiver is turned on and connected internally to the frame detection logic which is looking for a Wake Up Frame (WUF) as outlined in the Frame Detection section of the datasheet. The CAN bus data is not put on the RXD pin in this state. The device is supplied via the VSUP supply coming from the system battery.
The valid wakes up sources in selective wake mode are:
If a WUF and/or LWU event occurs, the wake request the corresponding wake event flag (WUF and/or LWU) flag is set. At this point, an interrupt is provided to the MCU using the nINT pin if enabled and by pulling down the RXD pin.
To enter selective wake mode, the following conditions must be met:
If a fault condition or FRAME_OVF forces the device into sleep mode, fail-safe mode disabled, or into fail-safe mode SW_EN is disabled turning off selective wake function.