A flexible, object-oriented SDR-framework in VHDL for the interconnection of HW and FW components

A universal software defined radio (SDR) system places high demands on performance, flexibility, reconfigurability and upgradeability. In order to realize all these characteristics, an FPGA is often the best choice. The effective interconnection of necessary hardware (HW) and the digital signal processing (DSP)-firmware (FW) requires a powerful framework. The target of this paper is to develop a best practice method for the concept of such a framework. The pragmatic use of the object-oriented (OO) opportunities like abstraction, encapsulation, records (classes) and instances is aimed to obtain the desired flexibility. Dynamic flexibility is supported by routing with multiplex-arrays in runtime. In order to save resources, static flexibility is implemented by static routing in the synthesis. The development of versatile HW- and FW-modules is enabled through uniform interfaces to the framework. These interfaces afford a top-level design with multifaceted input-output (IO) management. Plain VHDL (very-high-speed integrated circuits hardware description language) is used to meet these requirements. A central variant management is applied, so the FPGA (field-programmable gate array) can be configured easily and efficiently via multiple setup possibilities. The framework features a configuration and hardware description concept for rapid prototyping. It is perfect for employing modules from automated code generators and for partial FPGA reconfiguration. With this concept the developer can focus on development and implementation of the digital signal processing and only touches the connection issues of periphery and DSP-FW.