HW/SW Co-design Toolset for Customization of Exposed Datapath Processors

Customized processors are an interesting option for implementing software defined radios; they bring benefits of tailored fixed function hardware while adding new advantages such as reduced implementation verification effort and increased post-fabrication flexibility. To reduce the engineering costs and the time-to-market of platforms with new computing devices, the processor customization process should be supported with automated design flows that include tools like retargeting compilers, instruction-set simulators, and RTL generators. This chapter presents an open source processor co-design toolset that is based on a computation resource oriented design methodology where the primary design choices are the set of resources to include in the processor at hand, instead of focusing on instruction encoding details. The toolset is based on a retargetable high-level language compiler and a scalable exposed datapath template which support different styles of parallelism available in applications. In addition to various published academic processor design examples for SDR algorithms, the tools have been used to design and program processors that have been implemented down to silicon layout level and integrated in commercial grade chips.