HID detection issue

[annie_varshitha]

I have been facing HID Detection issues. Few boards get detected. Whereas the detecting boards are found to have the same issue sometimes. There are no hardware changes that can be differentiated between detecting and non-detecting boards. Voltages are proper. I have checked the power sequence as well as the USB CAP voltage. Sometimes it shows inconsistency in USB CAP voltage. We have used 12MHz crystal and frequency seems matching to the requirement. The D+ of non-detecting boards have 2.8V when 'USB DEVICE NOT RECOGNISED' appears. Kindly suggest the solution.

[annie_varshitha]

Does the amplitude of the clock generated by the crystal matters in HID detection? It is seen that the amplitude of clock generated by crystal is 1.1V and that of oscillator is 3.8V. Boards with oscillator gives better performance. Is there any criteria?

[annie_varshitha]

Hi igor,

   The crystal functionality seems proper and have taken care about the load capacitance as well as the drive level. The same crystal part works fine in other projects where there is no difference in processor and USB design. Could you please share the referance design of USB and crystal for imx6y2cvm08ab.

[igorpadykov]

one can check MCIMX6ULL-EVK_DESIGNFILES

Design files, including hardware schematics, Gerbers, and OrCAD files

Best regards
igor

[annie_varshitha]

i have attached the waveform of POR_B and 24MHz crystal. Kindly suggest if there are any other parameters causing this issue.@

[igorpadykov]

please look on https://www.testandmeasurementtips.com/measuring-clock-oscillator-frequency/ 

Best regards
igor

[igorpadykov]

Hi Annie

such issues usually are caused by crystal quality (non-stability)

issues and poor soldering. One can check Hardware Guide (available on processor web

product page) for crystal accuracy requirements and try to resolder problematic boards.

Best regards
igor
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[annie_varshitha]

*We have used 24MHz crystal.