GPIO pin states when power up on F28335

Alfred Zhong

Intellectual 370 points

Hi,

I am wondering what the default states are for all the GPIO pins on F28335, high or low?

From my experiences, they are high, I didn't test them all, but for the the ones I tested, they are all high.

I am having a hard time to find this information of the tons of manuals.

I found this wiki page

http://processors.wiki.ti.com/index.php?title=General_Purpose_IO_(GPIO)_FAQ_for_C2000

I says when power up, the GPIO pins are by default input. I don't know if this means all of them are high?

Is there any GPIOs are by default low or tri-state when powered up?

Thanks a trillion !!!

over 14 years ago

0 BrandonAzbell over 14 years ago

TI__Guru 64540 points

Two documents to reference. First, the datasheet which then points to the TMS320x2833x, 2823x System Control and Interrupts Reference Guide (Rev. D).

The datasheet in Section 4.13 illustrates the GPIO pin schematic.

Section 6.2 of the System Control and Interrupts Reference Guide discusses the internal pullup resistors on the GPIO pins. All GPIO-capable pins, with the exception of GPIO0 through GPIO11, have the pullup enabled by default.

This would explain why you measure most of the pins in a logic high state. By default, all GPIO pins are inputs.

0 Alfred Zhong over 14 years ago in reply to BrandonAzbell

Intellectual 370 points

Thanks a lot, Brandon!

--Alfred

C2000™︎ microcontrollers

C2000 microcontrollers forum

GPIO pin states when power up on F28335