sgt_johnny:
For circuit testing of my designs i would like to achive the most possible current draw, is there any way to do this in software?
No. The processor is capable of sourcing / sinking significantly more current then what the processor itself uses (up to 200 mA per VCC / GND pair). Getting to the "most possible current draw" entails connecting resistive loads to at least six pins on each port. (The processor does warm slightly when doing that.)