TUSB321: doubts on the CC controller DRP

Alder Lim

Prodigy 190 points

Part Number: TUSB321

Hi TI Guru

We are looking for designing a USB DRP product and TUSB321 come to our attention as it just need GPIO pin setting.

We are lacking of I2C resources thus this TUSB321 bring my attention.

I have some doubts below hopefully can get your help on these.

1. What happen if TUSB321 DRP connected to another DRP device, example when i set to DRP and connect to laptop type-C which is another DRP? or Tablet?

2. The port role configuration pin, it samples when a reset or power up. What is the reset here mean? is the USB unplug and plug back consider a reset?

3. If TUSB321 not suitable for my above application, can you recommend a replacement that without I2C?

Thanks in advance.

Best regards,
Alder

over 3 years ago

0 Brian Zhou over 3 years ago

TI__Guru*** 147985 points

1: when DRP connected to DRP, either one can be configured as DFP or UFP.

2: it mean power on reset, USB unplug and plug back is not reset.

3: TUSB321 should work for DRP appliaction.

Regards

Brian

0 Alder Lim over 3 years ago in reply to Brian Zhou

Prodigy 190 points

Thank you Brian for the reply.

I still have concern about 1.

When i set to DRP, i can not configured as DFP/UFP unless i power down and up again the TUSB321.

Let say, if i connected to laptop or tablet with USB type C (DRP), what will happen, will TUSB321 still work?

TUSB321 type-C (DRP) to laptop/tablet type-C (DRP)

Thanks,
Best regards,
Alder

0 Brian Zhou over 3 years ago in reply to Alder Lim

TI__Guru*** 147985 points

you can not configured TUSB321 as DFP or UFP. Whenever who's Rp is on the CC first, it will be configured as DFP, then the other one will be UFP.

Regards

Brian

0 Alder Lim over 3 years ago in reply to Brian Zhou

Prodigy 190 points

Thanks Brian.

"The TUSB321 device toggles between the UFP and the DFP if configured as a DRP. The PORT pin is only sampled at reset or power up."

Statement above from datasheet. if i set to DRP, and another device is also DRP, who's Rp is on the CC first, it will be configured as DFP, then the other one will be UFP.

Example below still work, is my understanding correct?

TUSB321 (DRP) <-------> TUSB321 (DRP)

Best regards,
Alder

0 Brian Zhou over 3 years ago in reply to Alder Lim

TI__Guru*** 147985 points

yes, it works.

Regards

brian

+1 Alder Lim over 3 years ago in reply to Brian Zhou

Prodigy 190 points

Thanks Brian

0 Alder Lim over 3 years ago in reply to Alder Lim

Prodigy 190 points

Sorry Brian,

I still have little doubt on below.

If TUSB321 connect to a DRP with try.src, will TUSB321 still work?

TUSB321 (DRP) <---> DRP try.src

Will TUSB321 configure to UFP ?

0 Brian Zhou over 3 years ago in reply to Alder Lim

TI__Guru*** 147985 points

in this case, TUSB321 will be configured as UFP .

Regards

Brian

0 Alder Lim over 3 years ago in reply to Brian Zhou

Prodigy 190 points

Thank you Brian.

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TUSB321: doubts on the CC controller DRP