The Atmegas have a number of power saving options. All of
them are available with the sleep instruction. Amforth has
a wrapper word with the same name which works on newer atmegas
only. You can simply include the file
dict_appl.inc file and try assembling. If it does
not produce an error, the sleep instruction can be used.
The next step is a system that uses interrupt driven terminal IO and possibly other interrupt sources. This makes it possible to include the sleep call into the pause deferred word.
: mypause 0 sleep ; ' mypause is pause
The exact meaning of the parameter (0) should be checked with the data sheet. Also make sure, that the interrupts are working properly. Otherwise the controller will sleep until the reset button is pressed..