Abstract:The designer of an FPGA embedded processor system has complete flexibility to select any combination of peripherals and controllers. In fact, the designer can invent new, unique peripherals that can be connected directly to the processor bus. If a designer has a non-standard requirement for a peripheral set, this can be met easily with an FPGA embedded processor system. For example, a designer would not easily find an off-the-shelf processor with ten UARTs. However, in an FPGA, this configuration is very easily accomplished.Keyword: Embedded Controller, VHDL (VHSIC Hardware Description Language), FPGA (Field Programmable Gate Arrays), Electronics Switch.
I. INTRODUCTIONFPGAs are increasingly used to implement embedded digital systems because of their low time-to-market and low costs compared to integrated circuit design, as well as their superior performance and area over a general purpose microprocessor. However, the hardware design necessary to achieve this superior performance and area is very difficult to perform causing long design times and preventing wide-spread adoption of FPGA technology. The amount of hardware design can be reduced by employing a microprocessor for less-critical computation in the system. Often this microprocessor is implemented using the FPGA reprogrammable fabric as a soft processor which can preserve the benefits of a single-chip FPGA solution without specializing the device with dedicated hard processors. Current soft processors have simple architectures that provide performance adequate for only the least-critical computations. Embedding a processor inside an FPGA has many advantages. Specific peripherals can be chosen based on the application, with unique user-designed peripherals being easily attached. A variety of memory controllers enhance the FPGA embedded processor system. interface capabilities. FPGA embedded processors use general-purpose FPGA logic to construct internal memory, processor busses, internal peripherals, and external peripheral controllers (including external memory controllers). Soft processors are built from general-purpose FPGA logic as well. As more pieces (busses, memory, memory controllers, peripherals, and peripheral controllers) are added to the embedded processor system, the system becomes increasingly more powerful and useful. However, these additions reduce performance and increase the embedded system cost, consuming FPGA resources. Likewise, large banks of external memory can be connected to the FPGA and accessed by the embedded processor system using included memory controllers. Unfortunately, the latency to access this external memory can have a significant, negative impact on performance.FPGA manufacturers often publish embedded processor performance benchmarks. Like all other companies running benchmarks, these FPGA manufacturers purposely construct and use an FPGA embedded processor system that performs the best for each specific benchmark. This means that the FPGA processor system constructed to run the benchmark has very few periph...
