In this paper the measurements taken for the development of instruction-level energy models for microprocessors are presented and analyzed. An appropriate measuring environment and a suitable measuring methodology were developed for taking the necessary measurements. The energy of an instruction is defined as a sum of three components, which are the pure base energy cost, the interinstruction cost, and the effect of the energy-sensitive factors (instruction parameters). These components are characterized for each instruction of the ARM7TDMI embedded processor, and their values are analyzed. Using the resulting models, estimates of the energy consumption of real software kernels with up to only 6% error were determined.