TMS320F28035: Configure wait time for GPIO pins from peripheral pins

ngohara1991

Part Number: TMS320F28035

I apologize if this has been answered elsewhere, but I am unsure how to search for this question.

Background:

I am working on fault cases for my I2C driver, and am trying to deal with the case about SDA line stuck low by other slaves, as discussed in http://processors.wiki.ti.com/index.php/I2C_Tips.

When I change the Gpio Pins 32 and 33 from their I2C peripheral configuration to GPIO inputs, is there any amount of time I need to wait before I read the pin state? Where would I look to find electrical settling time for this type of configuration change / GPIO input read?

I am running on a 60MHz operating frequency, and I intend to perform this check (change to gpio, Read, change back to I2C) as fast as possible, but I would like to be sure I'm not fooling myself timing wise.

Thank you for any advice,

Neal

over 7 years ago

0 Kevin Allen18 over 7 years ago

TI__Mastermind 43056 points

Hi Neal,

You're wanting to set SDA as a GPIO input and SCL as a GPIO output and then manually drive clock pulses (single master config)? Or are you trying to implement something else?

See processors.wiki.ti.com/.../General_Purpose_IO_(GPIO)_FAQ_for_C2000 for general GPIO answers.

Your question should be answered within the device specific data sheet "GPIO - Input Timing" and "GPIO - Output Timing" sections.

Hope this helps,
Kevin

0 ngohara1991 over 7 years ago in reply to Kevin Allen18

Intellectual 555 points

Thank you, the GPIO timing portion of the datasheet was what I didn't know to look for.
Neal

C2000™︎ microcontrollers

C2000 microcontrollers forum

TMS320F28035: Configure wait time for GPIO pins from peripheral pins