To Design a Real Time Scheduler for Embedded Systems using Hardware and Software Co Design Approch

Abstract

Embedded systems can no longer depend on independent hardware or software solutions to real time problems due to cost, efficiency, flexibility, upgradeability, and development time. System designers are now turning to hardware/software co-design approaches that offer real time capabilities while maintaining flexibility to support increasing complex systems. Although long desired, reconfigurable technologies and supporting design tools are finally reaching a level of maturity that are allowing system designers to perform hardware/software co-design of operating system core functionality such as time management and task scheduling that allow the advantages of higher level program development while achieving the performance potentials offered by execution of these functions in parallel hardware circuits. All event-scheduling functionality was migrated into hardware with a standard FPGA-based address mapped register set interface for the remainder of the operating system. This hardware-based event scheduling functionality liberated the CPU from performing the overhead processing associated with managing event queues, and provided microsecond resolution scheduling of events. The scheduler component of the Operating Systems was implemented in hardware using VHDL language and simulations were done using Model SIM software and synthesis using Leonardo Spectrum software. This work represented a critical first step towards achieving a full hardware/software co-design of key operating system functions into a hybrid system for embedded applications.