Building a SoC for industrial applications based on LEON microprocessor and a GNU/Linux distribution

This paper presents the design of a complete RTU (remote terminal unit) with a system-on-chip solution based completely on both open hardware and software platforms, and developed in conjunction with two industrial companies. The target implementation of the embedded system is a Spartan family FPGA from Xilinx. The article presents the main features of the base system, which consists of the LEON microprocessor and a Linux operating system distribution (Debian) running on it. Moreover, it shows a complete example of how to add new peripherals to the system. The peripheral that has been added is the UART 16550 compatible peripheral available in OpenCores. Given that the design has been prepared for the WishBone bus, it was necessary to adapt it to the APB bus within the LEON core. Furthermore, it has been adapted to work with the Linux driver for that UART to get a full coupling of peripheral with the system. The experimental results confirm the work done.