Abstract: A method and apparatus for generating a CMOS level clock signal from RC components for use in a microcontroller. The emulator includes an emulation chip and an emulation circuit. The emulation chip includes means for supporting RC clock input to accurately produce a sawtooth wave signal at the point of its connection with the RC network. The emulation circuit includes a comparator which transforms a sawtooth waveform produced by the emulation chip into a square waveform which is then inverted for use as a clock signal for a CMOS level microcontroller. The method includes the steps of emulating a clock signal input of an RC network, comparing the emulated RC signal to a reference signal to generate inverted square wave form output, and inverting the square wave form output for transformation into a CMOS level clock input suitable for use as a clock input for microcontrollers.