August 21, 2011 -- The three common processor implementation models used in FPGA cores are the microprocessor, microcontroller, and specialty processor. A microprocessor is generally a stand-alone core with limited peripherals. Microprocessors are usually implemented with at least a 32-bit or 64-bit architecture. They are generally targeted toward advanced computing applications.

In contrast to the microprocessor, microcontrollers generally include significant on-chip peripheral functionality. Microcontrollers are generally targeted toward specific application markets such as motor-control or PDA devices.

The target application influences the peripheral set mix. Microcontrollers follow the system on-chip (SOC) design philosophy. This philosophy encourages the implementation of as many peripherals on-chip as possible, ideally working toward a single-chip solution. Common peripheral block examples include Ethernet and USB communication and LCD controllers.

By R.C. Cofer and Ben Harding. (Cofer has almost 25 years of embedded design experience, including real-time DSP algorithm development, high-speed hardware, ASIC and FPGA and project focus; Harding has almost 20 years of experience in embedded systems design involving DSPs, network processors and programmable logic.)