TMS320C6748 USB unused pins?

Calum Mackinnon

Other Parts Discussed in Thread: TMS320C6748

Hey,

We are using theTMS320C6748. The datasheet says that USB0_VDDA12 must be connected to a 0.22uF capacitor - table 3.32 in the datasheet.

However the checklist here says that if both USB ports are not used then the pin should be a no connect - http://processors.wiki.ti.com/index.php/OMAP-L13x_/_C674x_/_AM1x_Schematic_Review_Checklist#USB

This is an avionics design that was done year or two ago and the original datasheet said to leave the pins unconnected. We are finishing verification and have just seen the updated datasheet.

Can you tell me if the datasheet is correct or the checklist?

Cheers

Calum

over 7 years ago

0 Shankari G over 7 years ago

TI__Mastermind 43955 points

Hi Calum,

For TMS320C6748, do you want to use the USB ports, USB0 or USB1 or both USB0 & USB1 or none of the USB ports ?

0 Calum Mackinnon over 7 years ago in reply to Shankari G

Genius 4155 points

We are not using any of the USB ports.

0 Shankari G over 7 years ago in reply to Calum Mackinnon

TI__Mastermind 43955 points

Hi Calcum,

Let me discuss with hardware experts and get back.

0 Ramakrishna over 7 years ago

Prodigy 30 points

Hi Calum Mackinnon,

If we are using any USB port then only we have to put capacitor. Unless it is not required for the design.

0 Andrew Tea over 7 years ago in reply to Shankari G

Prodigy 10 points

Interested in getting status updates from TI hardware experts.

0 Andrew Tea over 7 years ago in reply to Shankari G

Prodigy 10 points

Hi Shankari,
Do you have any further updates?

0 Mukul Bhatnagar over 7 years ago in reply to Andrew Tea

TI__Guru* 78305 points

Hi Andrew, Calum

Regret the confusion on this - however in general - when in doubt always trust the datasheet.
Wiki needs to be updated.

Some more details on the following E2E thread
e2e.ti.com/.../331496

Hope this helps.
Regards
Mukul

0 Brad Griffis over 7 years ago in reply to Mukul Bhatnagar

TI__Guru*** 125430 points

Andrew/Calum,

I've updated the wiki to make this clear:

processors.wiki.ti.com/.../_AM1x_Schematic_Review_Checklist

Thanks for raising this question.

Best regards,
Brad

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TMS320C6748 USB unused pins?