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TCAN4550-Q1: How to use the transceiver test mode and CAN core test mode?

Part Number: TCAN4550-Q1

Hello Expert,

TCAN4550-Q1 includes a test mode that has four configurations:

1. Transceiver Test Mode: Bit 21 (TEST_MODE_EN) of Modes of Operation and Pin Register (0800) is set, and the TEST_MODE_CONFIG (bit 0)= 0. In this mode, the transceiver TXD_INT_PHY is mapped to the CLCKOUT/GPIO1 pin, and RXD_INT_PHY is mapped to the GPO2 pin. EN_INT pin is mapped to the nINT pin.

What is EN_INT used for? In this mode, If I toggle GPIO1 to 1, is GPIO2 toggled to 1 also?

2. MCAN Core Test Mode: Bit 21 (TEST_MODE_EN) of Modes of Operation and Pin Register (0800) is set, and the TEST_MODE_CONFIG (bit 0)= 1. In this mode, the CAN core RXD_INT_CAN is mapped to the GPIO1 pin, and TXD_INT_CAN is mapped to the GPO2 pin. How do I use this mode?

Is GPIO2 equal to GPIO1 in this test mode?

Thanks in advance

  • QJ,

    In transceiver test mode, the device acts just as a typical CAN transceiver with GPIO1 acting as the TXD (transmit) pin, GPO2 acting as the RXD (receive) pin, and nINT acting as the EN pin. This is to test the transceiver portion of the chip without having to program the MRAM and send messages to and from the FIFO/buffers. A logic level message can be sent on the GPIO1 (TXD) pin, this will be reflected on the CANH and CANL pins, and then seen on GPO2 (RXD) with a delay associated with propagation. The nINT (EN) pin acts as the enable, controlling the mode of the device: if it is set to a logic high, the device is in normal mode, if it is set to a logic low, the device is in standby mode.

    In MCAN test mode, you can test your MCAN configuration and send messages on the RXD to verify that the receive buffers/FIFO are working. You can also store messages in the transmit buffer/FIFO and send them using the SPI registers, verifying that the MCAN outputs the messages correctly and with the correct configuration. Essentially, in this mode you are testing that your SPI configurations of the MRAM are working correctly. GPO2 is the transmit from the MCAN core, and the GPIO1 is the receive to the MCAN core.

    Both these modes take internal signals and mux them out to the GPO2 and GPIO1 pins to test the different parts of the integration before moving forward to using the product in the normal mode.

    Please let me know if that makes sense and if you have any other questions or concerns.

    Regards,
  • great answer, Thanks Eric