AVR-Chat

At 07:37 AM 4/5/2004 -0700, jay marante wrote:

>im using max883 as a linear regulator. its output is about 200-250mA of current. 

Your system draws that much?  If so, you seriously need a switcher.
The linear is wasting about 40% of the power available, and a switcher will not be more than 10%, and could reach 2% for an ideal design.

>how will i code the power-save mode in ICCAVR?

Complicated subject.

You have to determine how to configure the I/O ports so that the external stuff draws as little power as possible, then set the ports up that way.

You'll also have to pay attention to sequencing as you go to sleep, and as you wake up agian. There may be things in your externals that need to be done in a certain order to avoid damage, or large power draw.

In the chip, it's "simply" a matter of shutting off peripherals you aren't using, lowering clock speeds to minimum, and activating sleep.
The sleep instruction has to be preceeded by a sleep enable.

If course you also have to provide a wakeup mechanism.

It's not a simple thing.

Can you describe the system in more detail?