Prospects for using soft processors in systems-on-a-chip based on field-programmable gate arrays

Abstract

Objectives. Developing the element base of field-programmable gate arrays (FPGA) may significantly affect the design of electronic devices due to the enhanced logical capacity of such chips and the general tendency towards increased subsystem integration. The system-on-a-chip (SoC) concept is aimed at combining receiving, processing, and exchange subsystems onto a single chip, as well as at implementing control, diagnostic, and other auxiliary subsystems. The study aimed at developing a method for soft processor applications, i.e., processors based on configurable logical resources, for implementing control functions in an FPGA-based SoC.Methods. A digital system design methodology was used.Results. For soft processors, a unified design route based on selecting architectural parameters qualitatively corresponding to control tasks was considered. In particular, such parameters as instruction set addressness, number of pipeline cycles, and arithmetic logic unit configuration are adjustable at the design stage to allow the optimization of the soft processor in the discrete parameter space. An approach to rapid prototyping of the assembler based on stack-oriented programming language with regular grammar was also considered. The control of digital signal processing hardware as part of an SoC is the promising application area for soft processors. An implementation is considered on the example of an SoC based on Xilinx Virtex-7 FPGA containing several processor cores developed using the proposed methodology.Conclusions. The considered approaches to soft processor design allow the rapid prototyping of the control processor core for operation as part of an FPGA-based SoC.