For determining a power consumption of electrical circuitry, at least one device executes at least a portion of a software application having an effect on a current through the electrical circuitry. A current is generated through a transistor for mirroring the current through the electrical circuitry. In response to a control word, a reference current is generated. In response to executing the portion of the software application, the control word is varied to determine a value thereof that causes the reference current to approximately equal the current through the transistor, in a manner that correlates the effect of the portion of the software application on the current through the electrical circuitry.