![]() It therefore doesn’t make use of the explicit configuration logic of the host FPGA, increasing the amount of normal LUT resources used. This logic, which is used to configure the application bitstream onto the V-FPGA and to store the configuration for the V-FPGA Lookup Tables (LUTs), is usually implemented in host FPGA user logic. Area overhead is further caused by the structures of the V-FPGA itself, especially the configuration logic. Some of the difference is caused by different synthesis tools for the host FPGA and the V-FPGA: Whereas commercial vendor tools are used for host FPGAs, V-FPGA architectures commonly use the open source tool Versatile Place and Route (VPR). One example is area overhead of placed user applications, comparing total area required on the host FPGA including the virtualization layer to direct placement on the host FPGA. overhead of various kinds caused by the virtualization layer. V-FPGA architectures have to address various issues and limitations, some inherent in the very idea of a virtualization layer, such as e.g. Third, using the V-FPGA as a basic FPGA architecture: Here it is realized using standard synthesis approaches for silicon targets and can be used to evaluate the usage of different logic cell technologies in FPGAs. This becomes especially useful when investigating heterogeneous System-on-Chip (SoC) solutions, which may combine processing systems and reconfigurable logic. Second, V-FPGAs can be used for FPGA architecture research: Novel ideas can be integrated in the architecture and tested on a hardware implementation, which can provide additional insight compared to simulation. ![]() This allows using features such as partial dynamic reconfiguration on FPGAs which do not natively support this. V-FPGA architectures have been applied for three main use cases: First, as an abstraction layer, providing a common bitstream format independent of commercial FPGA architectures. ![]() User applications are synthesized using a custom toolchain for the V-FPGA layer and the resulting application bitstream is programmed onto it. The virtual layer is implemented as a bitstream to be programmed onto the host FPGA. Unlike common commercial and academic FPGAs, the V-FPGA is an FPGA architecture layered onto a base FPGA architecture: A commercial host FPGA architecture is synthesized for a silicon chip target, and the V-FPGA layer is synthesized for that host FPGA architecture. In recent years, virtual Field Programmable Gate Array (FPGA) architectures (V-FPGAs) have been been introduced in academia. Third, after evaluating Vivado synthesis strategies, we extend the timing model for non-uniform timings, achieving improvements of up to 28 %. Second, we propose a framework for automated timing extraction, enabling individual characterization of each V-FPGA design. We propose three approaches to attenuate these effects: First we introduce uniformity metrics and manual V-FPGA placement strategies for more uniform placement, improving achievable frequency by 16 %. The abstraction layer inherently induces overhead, but this aspect is reinforced by nonuniformity effects: When V-FPGA cells perform worse locally, basic architecture modeling generalizes these worst-case path delays to the whole device, limiting applications to a lower frequency than theoretically achievable. In these usecases, the achievable clock frequencies of V-FPGA user applications are a major concern. Virtual FPGAs (V-FPGAs) are used as vendor-independent virtualization layers, to retrofit features which are not available on the host FPGA and to prototype novel FPGA architectures.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |