How to enable CAN on MC33665A?

JWA74 — Mon, 15 Apr 2024 08:04:23 GMT

Hi NXP forum!

We purchased NXP’s 800 V Battery Management System (BMS) Reference Designs Using ETPL (https://www.nxp.com/design/design-center/development-boards-and-designs/800-v-battery-management-sys...) since we wanted a proper BMS to validate and test our battery emulator against.

Works great, currently we have been using FreeMaster and the example that exists for the reference design, referring to HVBMS_800_StartUp_FreeMASTER.pmpx, all measurements done by the BMS looks spot-on and as expected, same with the temperatures that we emulate through another board we have developed.

We have received a CAN database from support at NXP that we were told would work with the reference design BMU, see screenshot below, we have used the NXP_BMS_QPHY_V1.dbc. You can download the files here: MC33665A: Isolated Network High Speed Transceiver and CAN FD Gateway | NXP Semiconductors

We have connected our external CAN to the VCU_CAN port (that supports partial networking wake-up) on the RD-K358BMU using the DSUB connector that was included on the J1 connector cabling, according to the manual, to enable the VCU_CAN one can achieve it using the WUP on the SBC, or more specifically SBC WAKE1 input on the SBC.

No matter what we do we cannot see anything on the CAN bus, even when using a sniffer, so apparently, we have missed something fundamental.

The manual states:

“Vehicle control unit CAN (VCU CAN) is the main CAN interface equipped with high-speed TJA1145ATK/FD partial networking transceiver. This transceiver supports CAN partial networking by means of a selective wake-up function. The transceiver inhibit pin is connected to the SBC wake1 signal, which wakes up the system when the wake-up command is received on the VCU CAN port. To configure VCU CAN transceiver, use LPSPI5 PCS2.”

The last sentence is what I do not get, I understand that it is an onboard SPI node (node name: VCU CAN TJA1145A, IC Reference: U20, SPI Instance: LPSPI5, Peripheral chip selects: PCS2, Max Clk Speed: 2.5), but how should it be used and how do I get CAN communication going?

Thanks in advance for your help and guidance!

Regards,

JWA74

Re: How to enable CAN on MC33665A?

TomasVaverka — Tue, 16 Apr 2024 08:33:38 GMT

Hi Jimmie,

Here are some hints:.

The DBC files are meant to be used with the CAN-based CMU board directly. We actually have an example with documentation (based on the MC33775) published on the MC33665 webpage.
There is a CAN-based example code for the BMU available at: https://nxp.flexnetoperations.com/control/frse/product?child_plneID=860927

Hope it helps.

BR, Tomas

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How to enable CAN on MC33665A?

Re: How to enable CAN on MC33665A?