i.MX Processors中的主题 Re: i.mx 8m mini USB device is not recognized

i.mx 8m mini USB device is not recognized

Rajender — Fri, 03 Dec 2021 06:53:33 GMT

Hi,

We have developed a custom board using i.mx 8m mini processor. in which we are using USB 2.0 in host and device mode by using an USB mux and toggling USB ID pin.

We are operating the processor in serial download mode with the help of boot switches but it is showing "USB device is not recognized" and it is not detecting USB HID.

As we have only USB interface to download the image, we couldn't move ahead with the testing.

Please let us know what to do in this case.

Thanks

Re: i.mx 8m mini USB device is not recognized

igorpadykov — Fri, 03 Dec 2021 10:04:18 GMT

Hi Rajender

for this issue may be recommended to check hardware using Table 10. USB recommendations,

check 24MHz clock stability using Table 12. Oscillator/Crystal recommendations

i.MX 8M Mini Hardware Developer’s Guide

and try with several PC computers.

Best regards
igor

Re: i.mx 8m mini USB device is not recognized

Rajender — Fri, 03 Dec 2021 12:20:15 GMT

Hi Igor,

Thanks for the reply!
We have followed the hardware design guide document suggestions as in table 10 in our design.

We have selected the crystal with better specifications than mentioned in the Table 12. We powered the board and observed clock at 24MHz (processor is not flashed with any code as of now) and it's observed as 650Hertz. For confirmation we probed on TP38 of i.mx8m mini development board by powering it, it's observed as 700 Hertz.

powered it with multiple laptops and PCs. it's still showing the same.

Any other recommendations? do we need to install any specific drivers on our laptop?

Thanks

Re: i.mx 8m mini USB device is not recognized

igorpadykov — Fri, 03 Dec 2021 13:30:57 GMT

no additional drivers are not needed. Additionally one can try to test usb functionality

using procedures described in AN12409 i.MX6/7/8 series USB Certification Guide

>We powered the board and observed clock at 24MHz (processor is not flashed with

>any code as of now) and it's observed as 650Hertz. For confirmation we probed on TP38

>of i.mx8m mini development board by powering it, it's observed as 700 Hertz.

recommended to measure it with high impedance probe with high bandwidth oscilloscope.

Best regards
igor

Re: i.mx 8m mini USB device is not recognized

Rajender — Fri, 03 Dec 2021 14:10:26 GMT

We checked the connections again. It's detected as HID now.

Thanks Igor.