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

Question asked by JONGMIN NA on Oct 18, 2016
Latest reply on Oct 18, 2016 by Petr Stancik

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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