topic Re: i.MX53 USB_OTG_ID pin. in i.MX Processors

i.MX53 USB_OTG_ID pin.

satoshishimoda — Tue, 02 Sep 2014 04:42:23 GMT

Hi community,

I have some questions about i.MX53 USB_OTG_ID pin.

Please see my questions as following.

[Q1]

Please see Table 113 in IMX53CEC (Rev.6).

It shows the I/O buffer type of USB_OTG_ID is ANALOG25.

And power rail of it is USB_OTG_VDDA25, USB_OTG_VDDA33.

I want to know the relation ship between them.

Is ANALOG25 supplied power by USB_OTG_VDDA25?

If yes, how about USB_OTG_VDDA33?

[Q2]

Does i.MX53 USB_OTG_ID pin have a pull-down resistor?

If yes, could you let me know the resisotor value?

[Q3]

Could you let me know VIH and VIL and absolute maximum range of i.MX53 USB_OTG_ID pin?

Or it does not have VIH and VIL since this pin is analog?

Best Regards,

Satoshi Shimoda

Re: i.MX53 USB_OTG_ID pin.

igorpadykov — Tue, 02 Sep 2014 05:51:34 GMT

Hi Satoshi

1. both VDDA25 and USB_OTG_VDDA33 are used for analog

USB circuits. I am not sure what "relation ship between them"

you wish to know. Yes, ANALOG25 is supplied by USB_OTG_VDDA25.

2. please check bit IDPU "ID Pullup" register USB_UOG_OTGSC IMX53RM

Regarding pull value, i.MX53 complies with below specification .

3. please read USB specification about ID pin.

USB-IF Compliance Updates

Best regards

chip

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Re: i.MX53 USB_OTG_ID pin.

satoshishimoda — Mon, 08 Sep 2014 09:07:27 GMT

Hi chip,

Thank you for your reply.

> 3. please read USB specification about ID pin.

Yes,USB specification defines ID Pin's Resistance Ra_PLUG_ID and Rb_PLUG_ID.

But we guess i.MX6 monitor the ID pin voltage to detect the resistance.

So we want to know the threshold voltage.

Best Regards,

Satoshi Shimoda

Re: i.MX53 USB_OTG_ID pin.

igorpadykov — Mon, 08 Sep 2014 10:53:22 GMT

Hi Satoshi

I.MX6 complies whith USB specification for ID pin,

which defines only resistance.

Best regards

chip

Re: i.MX53 USB_OTG_ID pin.

satoshishimoda — Wed, 10 Sep 2014 07:39:39 GMT

Hi chip,

Thank you for your reply, and sorry I wrote "i.MX6" on 2014/09/08 but it was typo.

i.MX53 is correct.

> I.MX6 complies whith USB specification for ID pin,

> which defines only resistance.

Yes, we understand only resistance is defined by USB specification.

But we guess, to comply USB specification and to detect resistance, ID pin voltage or current detection circuit should be included in i.MX53.

So we want to know the threshold of the detection circuit.

Do you have the information?

Best Regards,

Satoshi Shimoda