topic Re: i.MX6 USB_OTG_ID signal - which pad is checked at powering up in i.MX Processors

i.MX6 USB_OTG_ID signal - which pad is checked at powering up

M_MA — Fri, 11 Mar 2022 14:41:33 GMT

I need to understand the pin/pad selection of the USB_OTG_ID signal.

According to the i.MX 6Dual/6Quad Applications Processor Reference Manual page 5073 the USB_OTG_ID Signal can be routed to the pad ENET_RX_ER or GPIO_1.

How does the iMX6 Processor know which pad is configured/chosen (as USB_OTG_ID) while powering up. Is it done via resistor combination at the EIM Bus or do I need to configure it in the MfgTool / UUU Tool?

Thanks

Re: i.MX6 USB_OTG_ID signal - which pad is checked at powering up

disheng — Mon, 14 Mar 2022 07:01:44 GMT

It is configured in the uboot and kernel device tree.

Re: i.MX6 USB_OTG_ID signal - which pad is checked at powering up

M_MA — Wed, 16 Mar 2022 10:01:02 GMT

I want to use MfgTool / UUU Tool to program initially the external SPI ROM of the iMX6 processor.

There is no SW (uboot/kernel) on the iMX6 device except the internal ROM bootloader.

Does this ROM bootloader decide which USB OTG ID pad is captured to set the USB OTG interface as host or device initially?

My worries are that the i.MX 6 will not be recognized as USB OTG Device for the initial programming.

Re: i.MX6 USB_OTG_ID signal - which pad is checked at powering up

disheng — Mon, 21 Mar 2022 06:16:34 GMT

Well the ROM code should be able to detect which pin is connected, otherwise it would be pretty stupid to allow to pins for USB OTG ID but only one is allowed in the ROM code