TMS320F28377D: CAN TX is not working . No output from CAN H pin while probing with oscilloscope

I checked the EVALUATION BOARD LAUNCHXL-F29379D output through CAN analyzer. I am getting output

But I have custom board which is TMS320F28377D  . I am not  getting any  output when i tried to probe with Oscilloscope and CAN analyzer

Please download my Application report http://www.ti.com/lit/SPRACE5. and look at the Debug tips provided. Most CAN issues can be resolved by going through this checklist.

I have created a video to help with the first communication project using DCAN: https://training.ti.com/getting-started-dcan-module. Please take a look.

Still I am not getting any output from CAN TX pin when I tried with can analyzer

Please report back on what you observed for each one of the debug tips I have provided.

Hey Hareesh Janakiraman!! I also have a similar issue. I am using the can_ex4_simple_transmit code from the examples for the launch-xl F28379D. I am using a Can Debugger from Kvaser CanKing to get the data from the MCU and i am able to get the data on the output window of the Kvaser CanKing software . I also have a F28377D-ep MCU on a custom board and i want to do the same on the custom board too. On the launch-xl board we have GPIO 12 and 17 connected to the j12 header as see below.

I have GPIO 38 and 39 on my MCU connected to a transceiver as seen below.

I have changed the GPIO 12 and 17 to GPIO 38 and 39 to test the same code on my custom board, but i am unsuccessful to do so. 

I can see the data getting populated as seen below.

Thanks for the debug document that you have provided above. I will report my observation with regards to the document on this thread. 

Thanks & Regards,

Denzil Rhodes.

Hey Hareesh Janakiraman, 

I believe i have configured the GPIO Pins correctly according to 4.1.1,

---> in main.c

--->in device.h

---> in pin_map.h

Here is also the pin allocation from the MCU to CANTXB and CANRXB,

Thanks & Regards,

Denzil Rhodes.

You need to remove the symbol _LAUNCHXL_F28379D from your project (everything under that #ifdef should appear greyed out).

Yes I have removed the symbol  _LAUNCHXL_F28379D  from my project.

Hello Hareesh , 

I  have posted the register values  by referring your checklist .

Debug Checklist

Programming Issues

1. Clock is enabled through a bit in the PCLKCR10 register

          2.No EDIS used in my code .

         3. No interrupts used in my code

          4.Mailboxes been enabled

• RAM_INIT_DONE --> CAN Mailbox RAM initialization status:

0 Read: Initialization is on-going or initialization not initiated.

1 Read: Initialization complete

• TxRqst --> Transmission Request Bits (for all message objects)

0 -  No transmission has been requested for this message object.

1 - The transmission of this message object is requested and is not

       yet done.

Note : Bit 0 is for mailbox 1, Bit 1 is for mailbox 2, Bit 2 is for mailbox , ……..

           Bit 31 is for mailbox 32

• TxRqstReg1 --> Transmit Request Register 1 flag:

Bit 0 - represents byte 0 of CAN_TXRQ_21 Register. If one or more                                              

           bits in that byte are set, then bit 0 will be set.

Bit 1 -  represents byte 1 of CAN_TXRQ_21 Register. If one or more

           bits in that byte are set, then bit 1 will be set.

• MsgValReg1 - Message Valid Register 1 flag:

Bit 0 - represents byte 0 of CAN_ MVAL _21 Register. If one or more

          bits in that byte are set, then bit 0 will be set.

Bit 1 - represents byte 1 of CAN_ MVAL _21 Register. If one or more

         bits in that byte are set, then bit 1 will be set.

--------------------------------------------------------------------------------------------------------

So these are the values I noticed in the CAN B registers .

Is there any registers , I missed to Enable ?

Hey Hareesh, I have same results on my end too. 

Thanks & Regards,

Denzil Rhodes.

Hey Hareesh!! I have swapped CAN A to CAN B in my code. Thanks for your time. The document helped alot.

Thanks & Regards,

Denzil Rhodes.