A rapid prototyping methodology for digital controllers is presented in this paper. Its main application is in the development, debugging, and test of microgrid inverter controllers. To fulfill the application requirements, these systems are characterized by complex multilayer architectures, extending from pulse width modulation (PWM) and current control loops up to global optimization and high level communication functions. The complexity and the wide variability of the different layer implementations make digital control mandatory. However, developing so complex digital controllers on conventional hardware platforms, like digital signal processors (DSPs) or even FPGAs, is not the most practical choice. This paper shows how multiplatform control devices, where software configurable DSP functions and programmable logic circuits are efficiently combined, represent the optimal solution for this field of application. Furthermore, this paper proposes hardware-in-the-loop real-time simulation as an effective means of developing and debugging complex hardware and software codesigned controllers. A case study is presented and used to illustrate the different design and test phases, from initial concept and numerical simulation to final experimental verification.