MSCAN and CAN-Phy implementation in S12ZVC MCU

[himanshusaxena1996]

We are currently developing a solution to connect a private CAN network with a public CAN on heavy-duty vehicles. To achieve this, we have decided to utilize the S12ZVC family MCU. However, we are encountering challenges in distinguishing between CAN-Phy and MSCAN implementation. Although the controller provides 2 ports for CAN, which can be used to communicate over 2 CAN buses, we have discovered that both CAN ports are internally connected, with no option to differentiate between incoming CAN data from each port. Given that our application requires interaction with 2 isolated CAN bus-lines, and in S12Z MCU we have one MSCAN. So we need guidance in understanding how CAN-phy is being used in this controller, is it possible to use CAN-phy ports and MSCAN ports in isolation over 2 different CAN-Bus lines?

[lama]

Hi,

The MCU contains a single CAN peripheral that can be seen on pins in multiple configurations.

See Figure 2-2. Illustration of CAN routing options.
Table 2-5. Preferred interface configurations.

Of course switching between M0C0RR[2:0] is possible

a) 0b000 which connect Rx/Tx via internal CAN transceiver to CAH and CANL pins

b) 0b110 which connect Rx/Tx directly to RXCAN0/TXCAN0 pins and the internal CAN transceiver is not used. It is necessary to add an external transmitter.

However, such switching is not a parallel connection to two CAN buses, but a quasi-parallel one, so data from the unconnected CAN bus will be lost.

No one around me has tested this approach.

Best regards,

Ladislav