USB device not detected

vincent_pelissi — Wed, 02 Sep 2020 14:26:07 GMT

Hello everyone,

I am designing a custom board with an i.MX6ULL processor with Linux version 4.14.78.

The uuu tool succeed in programming the eMMC with the fsl-image-qt5-validation-imx-imx6ull14x14evk.sdcard.bz2 file by using the USB port. When the board is ready (u-boot loaded and command prompt available on serial link), I plug a USB key but nothing appears (dmesg don't show any change). On previous prototype cards with same hardware the USB key was detected.

With memtool utility I have the following values on the registers PMU_REG_3P00 and PMU_MISC10:

root@imx6ull14x14evk:/# unit_tests/memtool -32 0x020C8120 1
E
Reading 0x1 count starting at address 0x020C8120

0x020C8120: 00011775

root@imx6ull14x14evk:/# unit_tests/memtool -32 0x020C8160 1
E
Reading 0x1 count starting at address 0x020C8160

0x020C8160: 00030000

This values are the same on the working and not working boards. The voltage on VDD_USB_CAP pin is 3.2V as expected. The USB key is supplied with an external +5V regulator.

My question is why USB key is not detected whereas uuu has successfully programmed the eMMC over USB port?

Thank you for your help.

Re: USB device not detected

igorpadykov — Wed, 02 Sep 2020 23:46:59 GMT

Hi vincent_pelissi

for usb stick please check that USB_ID signal is low, for uuu tool

i.MX is working as usb device and this signal is high or floating.

Best regards
igor

topic USB device not detected in i.MX Processors

USB device not detected

Re: USB device not detected