What is the History of PoC?

In the past years, a lot of “IP cores” were developed at the chair of VLSI design [1] . This lose set of HDL designs was gathered in an old-fashioned CVS repository and grow over the years to a collection of basic HDL implementations like ALUs, FIFOs, UARTs or RAM controllers. For their final projects (bachelor, master, diploma thesis) students got access to PoC, so they could focus more on their main tasks than wasting time in developing and testing basic IP implementations from scratch. But the library was initially for internal and educational use only.

As a university chair for VLSI design, we have a wide range of different FPGA prototyping boards from various vendors and device families as well as generations. So most of the IP cores were developed for both major FPGA vendor platforms and their specific vendor tool chains. The main focus was to describe hardware in a more flexible and generic way, so that an IP core could be reused on multiple target platforms.

As the number of cores increased, the set of common functions and types increased too. In the end PoC is not only a collection of IP cores, its also shipped with a set of packages containing utility functions, new types and type conversions, which are used by most of the cores. This makes PoC a library, not only a collection of IPs.

As we started to search for ways to publish IP cores and maybe the whole PoC-Library, we found several platforms on the Internet, but none was very convincing. Some collective websites contained inactive projects, others were controlled by companies without the possibility to contribute and the majority was a long list of private projects with at most a handful of IP cores. Another disagreement were the used license types for these projects. We decided to use the Apache License, because it has no copyleft rule, a patent clause and allows commercial usage.

We transformed the old CVS repository into three Git repositories: An internal repository for the full set of IP cores (incl. classified code), a public one and a repository for examples, called PoC-Examples, both hosted on GitHub. PoC itself can be integrated into other HDL projects as a library directory or a Git submodule. The preferred usage is the submodule integration, which has the advantage of linked repository versions from hosting Git and the submodule Git. This is already exemplified by our PoC-Examples repository.

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Footnotes

[1]	The PoC-Library is published and maintained by the Chair for VLSI Design, Diagnostics and Architecture - Faculty of Computer Science, Technische Universität Dresden, Germany http://tu-dresden.de/inf/vlsi-eda