Hi,
When testing the TJA1445 in Sleep mode, with the wake-up source mode set to WUF, VBATVCC defaulted to 0, CPNC configured to 1, and PNCOK configured to 1, why are CANH and CANL at a low level (0V) instead of 2.5V after entering Sleep mode? Is the CAN state "CAN Offline" at this time? How can I configure it so that CANH and CANL are at 2.5V when the TJA1445 enters Sleep mode? Because in the current testing environment, sending only one CAN message is insufficient to wake the TJA1445.
CH1 is the INH pin, and CH2 is the CANH pin. As you can see, the sleep mode is at a low level.
If the PN-related registers are set before power failure, VCC/VIO can be turned off, leaving only BAT.
Then, if a message matching WUP is found on the bus, it can enter CAN OfflineBias from CAN Offline. Upon receiving another message matching WUF, PN wake-up can be initiated.
The requirements of WUP messages are generally met by most messages; that is, sending two specific frames consecutively is sufficient to wake up the device.
When the board is in sleep mode and VCC is off, can't the TJA1445 wake up in one frame? Is it necessary to go through the CAN Offline to CAN OfflineBias process? At this time, can CANH and CANL be 2.5V, or does the TJA1445 enter Sleep mode while the CAN status is always in CAN Offline mode?