Hi,
When the TJA1145AT is configured to Wake-Up on pattern, the device wakes at all CAN messages.
The section 7.2.2 of the datasheet says:
"If the CAN transceiver is in Offline mode and CAN wake-up is enabled (CWE = 1), but
CAN selective wake-up is disabled (CPNC = 0 or PNCOK = 0), the TJA1145A will monitor
the bus for a standard wake-up pattern."
The problem is, that, the device, wake up to all CAN messages and not for the specific pattern for wake up.
The configuration steps used are:
- Set data rate (Register 0x26) to 500kbit/s (value 0x05).
- Set CAN Control (Register 0x20) to 0x00.
- Set Transceiver Event Enable (Register 0x23) to 0x01 (CWE set to 1).
- Set Wake Pin Enable (Register 0x4C) to 0x00.
- Clear all the Status Flags (System, Transceiver and Wake Pin Registers) writing 0xFF.
- Finally, set Mode Control (Register 0x01) to 0x01 (MC=0b001=Sleep_Mode).
At this point, the system go to sleep if the CAN Bus is inactive (no CAN Messages are coming from another nodes).
If the CAN Bus have activity with CAN Messages coming from another nodes, the transceiver Wake Up immediately and don't wait for the Wake Up pattern.
If the CAN Bus have no activity (No CAN messages in the Bus), the Transceiver goes to sleep and remains sleeping until a CAN Message is send by another node and no by the Wake Up Pattern specified in ISO 11898-2:2016.
What I expect to see at this point is, the transceiver only wake up with a wake up pattern and not for any CAN message detected in the bus.
What is wrong here? Is any configuration missing or wrong?
Best regards.
