Thus, an APU, via the instruction counters, will keep track of how many of each of these four different types of instructions are executed over a time period T. At the end of the time period T, the power information for APU 3110, i.e., the four different instruction counts, are provided to PU 203 (e.g., via an interrupt on bus 223) and APU 3110 resets the instruction counters.