TMS320F280049: C2000 CAN Bootloader

Before you start on the bootloader, you first need to ensure the LaunchPAD can communicate with your PC over the CAN bus. That is, make sure there are no hardware issues. I suggest you run at least one example from www.ti.com/lit/sprace5. Yu could run the simplest example, TXLOOP.c. Once you are sure the H/W is good, you can move to the bootloader.

Matteo Pirro said:

After power on the launchpad and send a CAN message (length=2 msgID=0x1) I expect to have an echo, but nothing happens.

There will be no "echo". The ACK from the 280049 is confirmation that the frame was received. Please go through the debug tips in SPRACE5 carefully.

I am sure CANbus is working correctly because I can send and receive messages to/from my PC

Anyway if a boot in CAN mode (Switch S2 GPIO32 ON(0) - GPIO33 OFF(1) on the launchpad) and I send a CAN message (length=2 msgID=0x1) I receive no ack. No messages at all.

Where am I wrong?

Thank you

Per Launchpad schematics, boot-mode select pins are GPIO24 and GPIO32.

the default can bootloader will not send an echo. may i know what caused you to have this expectation ?

Matteo,

          As clarified in my first reply to you, there will be no “echo” from the 280049 in the CAN bootloader. However, it should drive the ACK bit low upon successful reception of a frame. Fig 2-6 in SPRACE5 clearly shows the location of the ACK bit. You can probe both the CANTX & CANRX pins and check whether the ACK bit is being driven low by the 280049. This will confirm whether the frame was correctly received.

Sure, mine is a typo. GPIO24 and GPIO32 are the right one

SCI bootloader version works in that way: each received byte is sent back for validation. I assumed bootloader has the same behaviour regardless the used peripheral.

Now it is clear for me what you are saying Hareesh. But how can I know what I am sending is correct? Is there some debug I can do or I have to download all the kernel hoping I am doing the correct thing?

This needs to be debugged from both H/W and S/W perspective. 

Hardware: I know you have already tested CAN communication between the Launchpad and the PC. But, I would like you to test it under CAN boot mode. Please place an oscilloscope probe on D and R pins of U10 and send the first frame from the PC. If that frame was correctly received by the CAN module of 280049, it should generate an ACK. The captured waveform should look like Fig 2-6 of SPRACE5. In other words, we should be clearly able to see the ACK signal. Read the debug tips in SPRA876 very carefully. SPRACU9 has very informative scope captures. 

If the above experiment is successful, we can move to software.