S32K144 CAN_FD 4M ERROR

[kirkgong]

Config can fd data field baudrate 2M CAN Transmit correct, but change to 4M can not transmit data field (the control field is correct),

[PetrS]

Hi,

for 4Mbps data rate a TDC has to be enabled to allow proper bit detection on transceiver RX pin.

So do you set TDCEN bit and calculate TDCOFF properly?

You can use CAN bit timing calculator (https://community.nxp.com/docs/DOC-342618) for this.

BR, Petr

[kirkgong]

Hi Petr Stancik,

   Thank you for your help! CAN_FD can send data correct at 4M baudrate.But at this time ,I have to connect Tx pin and Rx pin directly. otherwise it can not send data field. I think  that the signal conduct to Rx pin from transceiver have a little delay (about 125 ns). This delay influence the data send at 4M baudrate. So i connect Tx pin and rx pin directly can send data.  I test this case with S32K144EVB-Q100, the transceiver is UJA1169TK/F, I look up the transceiver datasheet found UJA1169TK/F support only 2M baudrate.

I have two question ,

1.Although it can send data at 4M baudrate, but I can not use it normally Because it can not connect to transceiver.

2.Although it can send data at 4M baudrate, when i config data baudrate to 8M it can not send data field again 

[sreevishakhkp]

Can you share the code please

[kirkgong]

It's a keil project that can not share it on this page,can you tell me what problem you have.    CAN Bit Timing calculation v1.0 excel can help you config the baudrate, if you want use higher baudrate ,you need enable the TDC function.

[sreevishakhkp]

Hi Kirk,

I am using S32k144 .I need CAN FD frame with 5000Kbps.I modified example project given in s32Design Stdio but it didnot work.It worked with 500kbps.Can you help me to configure it for 5000kbps

[kirkgong]

can you tell me your email address or we chat account ?this page can not send attachment.

[sreevishakhkp]

Are you using external oscillator as clock source?

[sreevishakhkp]

sreevishakh@gmail.com

[PetrS]

Hi,

if using external loopback for test, 8M should work too, I think, but SSP must be properly set or TDC disabled.

BR, Petr