1. A circuit, comprising: a resistive element; and a cascode current mirror circuit having a reference current stage and a number of mirrored current stages, the reference current stage being selectively coupled between a voltage and the resistive element, wherein the number of mirror current stages corresponds to a number of boundaries between resistance states, and each of the mirror current stages are coupled to the voltage to provide in parallel a respective mirror current proportional to a current flowing through the resistive element.