Colfire 1, this uses a lot of current

[Gabriel_Medelli]

Good night, someone can tell me if the ports must be configured as either inputs or outputs, and that way, to avoid the high current consumption of the system, since apparently the current absorbed by colfire unused ports.

thanks

Regards

[TomE]

What current are you measuring? What do you expect (and what section of what data sheet are you reading)?

What MODES do you have the CPU running in, what clock speed and so on?

Can you separately measure the CPU current and that being used by the rest of your board?

You should be on the Coldfire forum for these questions.

Tom

[rocco]

Hi Gabriel,

Welcome back to the forum.

I don't have direct experience with Coldfire-1, but in general, if an input pin is left to float between the rails, then they can draw a lot of current. If an input is not driven, then it should have a pull-up or pull-down resistor to bring it to one of the rails. Most newer Freescale MCUs have built in pull-ups, but they are typically enabled under software control, and might default to disabled. The safest thing to do with unused I/O is to program them as outputs.