i.MX93 custom board – DDR configuration vs bootloader flashing order

[Khaled_Gued]

Hello,

We have developed a custom board based on the NXP i.MX93, with DDR4 RAM and flash memory. In other words, we replicated the required parts of the schematics from the i.MX93 EVK.

For connectivity, we kept two interfaces:

- UART via FTDI for debugging

- USB1 for flashing the i.MX

From our understanding of the workflow:

1- Configure DDR with the NXP Config Tool.

2- We need to flash the bootloader.
3- Finally flash the Linux image we generate with Yocto.

However, we are unsure about the correct order of operations.

On the EVK, we successfully validated DDR configuration with the Config Tool via USB.

On our custom board, when we try to validate the DDR configuration (generated with the i.MX Config Tool), the communication over USB1 to the i.MX is not being established.

So my questions are:

- Is it actually correct to start with DDR configuration before flashing the bootloader, or should the bootloader be flashed first?

- If DDR configuration is indeed the first step, why would the Config Tool validation fail on our custom board while it works fine on the EVK?

Any guidance on the proper bring-up sequence and potential causes of this USB communication issue would be very helpful.

Thanks in advance!

 

[Khaled_Gued]

Thank you for the clarification, Indeed the problem was in the communication.
I have solved that issue and the comm is starting however im getting another error : 
ERROR memtool.common.base_test Application load ended with exception: Download incomplete due to configuration error!

Can you please guide me to what it potentially could be ? 
Thank you in advance ! 
Best regards 

[JorgeCas · Accepted solution]

Hello,

This error indicates a failure during DDR application loading to the board. There are several reasons for this behavior.

1. The board didn't power-up correctly. Was it verified that all the rails come up in the correct order and to the desired voltages? Can the board be seen in the PC's device manager as HID device?

2. Bootrom is not responding anymore. This typically happens when there are USB connection issues. Any chance trying this with a different USB cable and PC?

3. Do multiple boards behave this way or just one unit?

4. Could you please share the exact part number you are using?

Best regards.

[Khaled_Gued]

1. The board didn't power-up correctly. Was it verified that all the rails come up in the correct order and to the desired voltages? Can the board be seen in the PC's device manager as HID device?
The board is powered up correctly and it is seen as HID Device by the PC

2. Bootrom is not responding anymore. This typically happens when there are USB connection issues. Any chance trying this with a different USB cable and PC?
I tried with different USB and PC, sale problem

3. Do multiple boards behave this way or just one unit?
For now we are only testing with one board, I am going to test with another one 

4. Could you please share the exact part number you are using?
the part number I am using is the PIMX9352AVTMAB

[JorgeCas]

Hello,

Your workflow understanding is correct.

- Is it actually correct to start with DDR configuration before flashing the bootloader, or should the bootloader be flashed first?

You need to run the DDR stress test to generate de initialization/timing to build your bootloader/image. During the DDR stress test, the board will be in serial download mode.

- If DDR configuration is indeed the first step, why would the Config Tool validation fail on our custom board while it works fine on the EVK?

The error log you are getting is caused by unstable UART COM connection to your board from PC host. Please check that you are connecting your board to the correct COM port and also please you schematic connections.

Best regards.