CAN FD (MCAN) Configuration with MPC5777C and TJA1145T/FD

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CAN FD (MCAN) Configuration with MPC5777C and TJA1145T/FD

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jongminna
Contributor III

Dear all,

 

I've tested with NXP's MPC5777C example code for MCAN configuration.

 

I want to implement CAN FD.

So It works well below configuration..

1. Maximum baudrate : 3.3Mbps (As you know, CAN FD baud rate is set 2, 4, 8Mbps. But I tested 1Mbps, 2Mbps, and 3.xxMbps through adust a DTSEG1, DTSEG2. Below 3.xxMbps work well, There is no error. But 4 and 8Mbps don't work well, CAN Communication always failed)

2. Maximum data length : 64Byte. It is Ok.

 

 

More specific, When I configured DBTP(same as FBTP) value as 4Mbps.. Like these 2 cases.

Both of them don't work well...

Our XOSC is 40MHz, and MCAN clock rerence is XOSC(40MHz)

 

Case 1:

    MCAN_0.FBTP.B.FBRP = 0x0;
    MCAN_0.FBTP.B.FTSEG1 = 5;
 MCAN_0.FBTP.B.FTSEG2 = 2;
 MCAN_0.FBTP.B.FSJW = 2;

 

Case 2:

    MCAN_0.FBTP.B.FBRP = 0x1;
    MCAN_0.FBTP.B.FTSEG1 = 2;
 MCAN_0.FBTP.B.FTSEG2 = 0;
 MCAN_0.FBTP.B.FSJW = 1; 

 

 

So I guess that main reason of this situation(baud rate limitation as 3.xxMbps) is that our CAN Transceiver NXP TJA1145T/FD can't support above 2Mbps.

Is it right?

Or MY FBTP configuartion is incorrect?

Addtionally, Also 8Mbps doesn't work well...

 

 

Please give me advice.

Thanks everyone.

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PetrS
NXP TechSupport
NXP TechSupport

Hi,

yes, on this transceiver the timing is guaranteed for data rates up to 2 Mbit/s.

Moreover for the data phase you also need to set the TDC properly otherwise you will detect error still. See more in chapter 41.5.1.4 Transmitter Delay Compensation of the Reference Manual.

BR, Petr

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