First and foremost, it appears that GreenSocs has just released GreenBus using an open source ESL package management system. There are two points of interest here: GreenBus itself and the package management system.

GreenBus
With regard to GreenBus, this really isn't a bus! In fact, GreenBus is a versatile SystemC framework with which to model busses, aiming at simulation models of complex on-chip communication architectures. In addition to the bus fabric itself, GreenBus also provides other related services such as logging and configuration. There are three main parts to the GreenBus fabric as follows:

1. A bus core protocol definition known as the TAQ. This includes both the data types that are transported across the bus (byte lane enables, lock, read-not write, etc) and the representation of arbitrary timing and arbitration protocols. GreenBus comes complete with a set of data types that minimize the "conversion" required.
2. A user API layer, which enables users to define their own bus independent API.
3. A communication router, which is bus- and user-API-independent. The router takes the application-specific protocol definition and provides a well implemented fast communication router which works at several abstraction levels.

The advantage of this approach is that it enables easy IP reuse since the user API is independent of the bus fabric, and as standards are developed (i.e. the OSCI TLM standard which is currently being worked on), GreenBus will remain compliant with it, while user code can remain unchanged.

The package management system
The package management system makes installing, trying, upgrading, and discarding packages (software applications) very easy. Also, you can use it as a user – there's no need to be the 'root' – and it works on all Linux's.

Of particular interest is the fact that this system is based on open source, which means that any EDA company could use it to release their own kit and benefit from the ease of use and known user environment (although it's open source, the packages inside it can be proprietary, FLEXlm guarded etc.)

Mark says that in his humble opinion, this is the most important piece of ESL environmental infrastructure that they have built, and it's free for ESL companies to use.

As Mark notes: "One of the biggest costs for user companies is evaluating new ESL tools (just the 'install' and 'remove' can often be a real pain) – this package management system make all of this stuff very much easier."

GreenSocs meeting at DAC (and free socks)
One of the surprisingly hot items at last year's DAC was GreenSoc's "Birds of a Feather" meeting. Mark plans on keeping the ball rolling at this year's DAC with a public meeting in room 111 on Thursday 27th July between 11:00 am and 1:30 pm.

As part of this meeting there will be a tutorial covering the following topics:

• GreenBus is available to all – it's Open Source – so how do you get it?
• How GreenBus achieves interoperability, safety, and speed.
• Fundamentals of the GreenBus interconnect framework.
• Support for the TLM WG 1.0 interfaces.
• Defining your own protocols.
• Integrating GreenBus into your SystemC environment.

There will also be some demos on Eclipse environments (which will become open source), and on analysis and profiling tools which will also become open source. And, of course, let's not forget the free socks! Perhaps you'll see me there (I'll be easy to spot; I'll be the only one in a Hawaiian shirt, shorts, and bright green socks!)