AM3358: USB Controller change to Host mode from Peripheral mode by USB_ID

takeshi matsuzaki

Expert 2030 points

Part Number: AM3358
Other Parts Discussed in Thread: TUSB320LAI

Hello,

If AM335x USB Controller has been already initialized as a USB Peripheral(USB_ID=Hi), can it change to USB Host automatically by giving "Lo" to USB_ID terminal ?

seeing this check list..
processors.wiki.ti.com/.../AM335x_Schematic_Checklist
USB0_ID and USB1_ID should be open-circuit when the USB port is configured to operate in USB peripheral mode.
So AM335x USB Controller seems not to expect USB_ID to change to Lo when in peripheral mode.

In another word, is there any way to change AM335x USB Controller to Host mode from Peripheral mode by connecting USB memory(for example..) when AM335x USB is Peripheral mode ?

Regards,
Takeshi Matsuzaki

over 7 years ago

0 Bin Liu over 7 years ago

TI__Guru**** 178611 points

Hi Takeshi-san,

What is the OS?
How do you control the USB ID to hi or lo? by a switch on the board or usb cable?

Please note that due to the holidays my further response might be delayed.

0 takeshi matsuzaki over 7 years ago in reply to Bin Liu

Expert 2030 points

Hi Liu-san,

The OS is Linux.

USB ID is controled by "TUSB320LAI".
Actually, my customer has "USB Type-C" connector on their boad, and some middle logic including TUSB320LAI,
and AM335x USB port behind the TUSB320LAI.

AM335x USB port is initialized as a Peripheral(USB_ID=Hi) first, and then USB_ID comes to Lo when USB memory is connected to the "USB Type-C" connector on their boad.

They expect AM335x USB port becomes to USB Host automatically by changing of USB_ID Hi to Lo.

Regards,
Takeshi Matsuzaki

0 Bin Liu over 7 years ago in reply to takeshi matsuzaki

TI__Guru**** 178611 points

Hi Takeshi-san,

Please ensure the dr_mode in device tree is set to 'otg'. Then if the USB port is NOT connected to a USB host, switching USB_ID pin to low should set the USB port to host mode.

I am not familiar with TUSB320LAI, can you please describe how the AM335x USB ID pin is controller by it? or please provide its related portion of the schematics.

Please note that AM335x USB ID pin requires less than 100 ohm resistance when it is grounded (low).

0 -DK- over 7 years ago in reply to takeshi matsuzaki

TI__Mastermind 27890 points

Hello,
I'm also waiting for your answer to Bin's questions, but thought I would point out that USBn_ID can never have voltage applied or the part will be damaged.

I do not support the 320LAI device so I am unfamiliar with it. I hope when you said "USB_ID=Hi", you mean float.

0 takeshi matsuzaki over 7 years ago in reply to Bin Liu

Expert 2030 points

Hi Bin, DK,

Thanks for your reply, and sorry for my late reply.
We've been takeing new year holiday these days.
Now I'm working on this.

Regards,
Takeshi Matsuzaki

0 takeshi matsuzaki over 7 years ago in reply to Bin Liu

Expert 2030 points

Hi,

AM335x USB ID pin is controlled like follows.

USBn_ID has voltage applied by 120kΩ Pull Up. Does this circuit damage AM335x?

AM335x didn't change to USB Host even they pulled off the 120kΩ Pull Up.

Regards,
Takeshi Matsuzaki

0 takeshi matsuzaki over 7 years ago in reply to Bin Liu

Expert 2030 points

Bin,

Sorry for replying to your question separately.

> Please ensure the dr_mode in device tree is set to 'otg'.

My customer says dr_mode in device tree is set to 'otg'.

Regards,
Takeshi Matsuzaki

0 takeshi matsuzaki over 7 years ago in reply to -DK-

Expert 2030 points

Hi,

My customer decided to pend this case once from their business policy or schedule.
This thread will be closed but they preserve plans to make AM335x USB(2.0) to USB Type-C as a long-term goal.
If you have any ideas, that would be appreciated.

Thanks.
Takeshi Matsuzaki

0 -DK- over 7 years ago in reply to takeshi matsuzaki

TI__Mastermind 27890 points

Matsuzaki-san,
Yes, this circuit will certainly damage the AM335x device. Please see bullet #1 in the schematic review checklist.
processors.wiki.ti.com/.../AM335x_Schematic_Checklist

0 takeshi matsuzaki over 7 years ago in reply to -DK-

Expert 2030 points

Hi DK,

Thank you very carefully to the end.

Regards,
Takehsi Matsuzaki

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AM3358: USB Controller change to Host mode from Peripheral mode by USB_ID