Where is the MC33903 in FRDM-S32K144 EVB? What should I do about it before I use the CAN bus?

[maxmathew]

 I have a S32K144 EVB board.These days I want to use CAN bus and I have read the " S32K14x Series Reference Manual". It seems that I can use CAN by configuring the register in S32K144 according to the " Reference Manual". But,the example for S32K144 in S32DS have something about "MC333903", but I can not find anything about "MC333903" in the " Reference Manual". I want to know whether I need to read other Manuals in order to use CAN bus.

[danielmartynek]

Hi,

There are currently two boards FRDMPK144-Q100 and S32K144EVB-Q100.

The MC33903 is a system basis chip (SBC) with CAN transceiver on FRDMPK144-Q100.

Whereas S32K144EVB-Q100 has UJA1169. Both chips are configurable via SPI.

You can configure only FlexCAN (output/input on CAN_RX, CAN_TX) using S32K144 registers. But if you need CAN interface (CAN_HI, CAN_LO) you need the SBC or other CAN transceiver.

Regards,

Daniel

[maxmathew]

My board is FRDM-S32K144. I can find TJA1050, however I can not find MC33903 or UJA1169. Should I worry about this? Can TJA1050 work as transceiver without any configuration?

[danielmartynek]

Hi,

In case you have TJA1050 CAN transceiver on that board, you can use it without any configuration.

Regards,

Daniel

[maxmathew]

Thank you very much! You have helped me solve the confusion!