topic Re: CAN FD NACK Error S32k144 in S32K

CAN FD NACK Error S32k144

marwanibrahim — Thu, 23 Jul 2020 00:03:44 GMT

Hello,

I am using S32k144 evaluation board and i am trying to establish CAN FD communication between it and Canoe environment.

I configured S32k144 with arbitration phase bit rate 500kb/s and data phase bit rate 1Mb/s

When i start canoe, it gives me not acknowledge error:

So, i want to ask you if NACK error can happen because of clock settings issues in both sides?

S32k144 parameters:

Clock 80Mhz

Arbitration phase params:

BR: 500k
BR prescaler: 16
Prop Seg: 5
Seg1: 2
Seg2: 2
Sjw: 1

Data phase params:

BR: 1M
BR prescaler: 4
Prop Seg: 11
Seg1: 4
Seg2: 4
Sjw: 2
Trcv delay compensation offset: 300
BRS is enabled

And Canoe settings:

Appreciate your kind support,

Thank you.

Re: CAN FD NACK Error S32k144

PetrS — Thu, 23 Jul 2020 07:10:33 GMT

Hi,

be sure FlexCAN operates using the ISO CAN FD protocol so you have CTRL2[ISOCANFDEN] bit set.

Or configure it according the CAN tool setting, but this appears using ISO CAN FD.

For the CAN bit setting configure it to have the same sample point as CAN tool. It is recommended to have same prescaler and TDC is not needed for this rates. You can use e.g.

CANx_CBT = 0x806B29EB; // bitrate=500kbps, CPI clk=80 MHz; Prescaler= 4, PROPSEG=11, PSEG1=16, PSEG2=12, RJW=12, smp=70%

CANx_FDCBT = 0x003514E5; // bitrateFD=1000kbps, CPI clk=80 MHz; fPrescaler= 4, fPROPSEG=5, fPSEG1=8, fPSEG2=6, fRJW=6, smp=70%

BR, Petr

Re: CAN FD NACK Error S32k144

marwanibrahim — Sun, 26 Jul 2020 12:58:28 GMT

Thank you for your reply, Petr.

Yes, i can confirm that the problem was in ISO CAN FD enable bit, it wasn't set so i was wrongly working on NON ISO CAN FD.

Thank you again.