CCS/TMDSCNCD280049C: Communication not possible with CAN bootloader

David Baltaro

Prodigy 150 points

Part Number: TMDSCNCD280049C
Other Parts Discussed in Thread: C2000WARE

Tool/software: Code Composer Studio

Hello,

I can't establish communication with the CAN controller in CAN boot mode. I'm using

- 280049C control card with docking station,

- IXXAT USB-to-CAN II module

- an old PCA82C250 CAN transceiver with 3V3 to 5V signal level adapter.

- code composer 9, CGT 18.12.4

In this configuration, "can_ex3_external_transmit" T.I. provided example works as expected after light modifications.

In this context, I set the different values in expressions window:

- (unsigned long*)0xD00 <= 0xA5FFFFFF i.e. EMU-BOOTPIN-CONFIG key to select one boot mode

- (unsigned long*)0xD04 : 0x00000022 i.e. EMU-BOOTDEF-LOW value for CAN boot mode with GPIO4(TXA - HSEC50) and GPIO5(RXA - HSEC-52)

Then I reset with realtime emulation control / run_realtime_with_reset

DSP reset, CAN boot mode is executing, waiting for 0x08AA key value

Then I send the expected key value AA08 ; Id 1, with USB_TO_CAN module, but at this stage, any data send at any speed cause CAN errors in USB-To-Can module interface. (parameters : Can protocol Standard at 100 Kbits/s)

What I've done after :

- loaded symbols of Bootrom from C2000ware (F28004X_ROM_PG2.0_2_7_17) to follow program execution after reset : init is done correctly, pins are configured correctly for CAN boot, waiting at

"if (DCAN_GetWordData() != 0x08AA)"

- tested different CAN pins (the ones corresponding to 0x2 / 0x22 / 0x42)

- tested with optional "DCAN_BOOT_SENDTEST" enabled (0xA2 instead of 0x22 for CAN boot mode). This time, USB_TO_CAN module interface received errors

- tested : loading the can_ex3_external_transmit program after POR (which configures clk XTAL / PLL) the performed emulator reset (run->CPU_reset)

- tested : NOT loading the can_ex3_external_transmit program after POR. So in this case, only EMU-BOOTPIN-CONFIG / EMU-BOOTDEF-LOW are modified before reset, and default PLL are the loaded.

- Tested : changed can speed on USB_TO_CAN inferface from 20 kb/s to 500 kb/s. But default values with controlcard at reset should be at 100 kb/s, right ?

- Tested : another 280049 controlcard...

In any cases, Tx | other error or Rx | Other error or stuff errors are displayed in USB_TO_CAN interface modules.

Any advice ? where I'm wrong ?

Thanks by avance,

David

over 6 years ago

0 Krishna Allam over 6 years ago

TI__Expert 7985 points

Dear David,

We are reviewing your request and will get back to you. Thanks, Krishna

0 Hareesh Janakiraman over 6 years ago in reply to Krishna Allam

TI__Guru* 95315 points

David,

The fact that you are able to get "can_ex3_external_transmit" example working successfully indicates that your H/W and wiring is likely good.

Can you capture the waveform at the CANRX pin when the host is transmitting 0x08AA? Please see http://www.ti.com/lit/sprace5 for sample waveforms.

0 David Baltaro over 6 years ago in reply to Hareesh Janakiraman

Prodigy 150 points

Thank you for the documentation, she directed me to the solution.

The homemade 5V to 3V3 signal level adapter, on CAN RX pin uses a divider bridge which conflicts with pull-up resistor which enabled by default on can bootrom. Pull-up is not enabled on can_ex3_external_transmit example, which made it harder to understand the problem.

The ability to send a test pattern

//Send two tests frames if the boot mode says so
if (bootMode & DCAN_BOOT_SENDTEST)
{
DCAN_SendWordData(0x0320);
DCAN_SendWordData(0xf280);
}

was a big help. It would deserve to have an entry in the technical manual (sprui33)

Thanks again, you can close the thread.

0 Hareesh Janakiraman over 6 years ago in reply to David Baltaro

TI__Guru* 95315 points

Good to know the problem was resolved. We will add this feature to the TRM as you had suggested.

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CCS/TMDSCNCD280049C: Communication not possible with CAN bootloader