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PSoC™ 5, 3 & 1

MaMi_1205306
Honored Contributor

Hi,

I would like to confirm about the treatment of unused GPIO.

It is described in AN 80994 as follows.

AN80994

http://www.cypress.com/documentation/application-notes/an80994-design-considerations-electrical-fast...

"Terminate the unused I/O lines to ground or supply through resistors of typical value of 10 k."

We understand that it implements resistors on the unused pins of analog Hi-Z.

Instead of implementing external resistors, Is it effective to pull up/pull donw unused pins in PSoC internal NVL setting?

Regards,

Masashi

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1 Solution
LinglingG_46
Moderator
Moderator

"The internal pull up / pull down of PSoC can not obtain the effect of EFT"

The understanding is OK.

View solution in original post

3 Replies
LinglingG_46
Moderator
Moderator

Hi Masashi,

The linker file you give is the EFT Design Consideration Guide line.

It is sure that the used GPIO is configured in  analog high Z drive mode.

I think you don't use the pull up /pull down resistor unused pin instead on external resistor.

If you use the internal resistor, then it is not in the Analog High Z drive mode.

Thanks

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MaMi_1205306
Honored Contributor

Thanks,

It was an idea to reduce the number of external resistors.

"The internal pull up / pull down of PSoC can not obtain the effect of EFT"

Is it OK with the above understanding?

Regards,

0 Likes
LinglingG_46
Moderator
Moderator

"The internal pull up / pull down of PSoC can not obtain the effect of EFT"

The understanding is OK.

View solution in original post