100 MHz High Speed SPI Master: Design, Implementation and Study on Limitations of using SPI at High Speed

Abstract

SPI or Serial Peripheral Interface is among the fastest synchronous serial communication protocols used in embedded systems. High throughput and simplicity of SPI communication has made SPI protocol; a de facto standard. Designs based on FPGAs (Field Programmable Gate Arrays) enhance reusability, flexibility and faster prototyping of digital systems, especially serial buses, which are inevitable in almost all designs. This paper discusses the design and implementation of a 100 MHz High Speed SPI Master Core on FPGA. State machine approach is employed for the RTL (Register Transfer Level) design of the core. The paper also discusses the challenges and limitations of implementing such a high speed SPI bus in digital systems. The SPI Master Core was successfully implemented on Altera Cyclone III FPGA for a speed of 100 MHz.