A View from the Top: A Virtual Prototyping Blog

It’s all about the models. We have been using this tag line here at Synopsys for a while now. Now that SystemC TLM-2.0 finds more and more adoption in the industry, the focus is shifting from proprietary simulation by itself to standards based simulation. That shift enables interoperability and with that the models become much more important, just as the productivity tools making life with simulations easier.

Sometimes the challenge with abstract models can be … that they are abstract and that they are models. Per definition they are omitting information. That may be OK for abstract are like the “Model for an Unknown Monument” to the left (Source: EspenDietrichson). It requires some thought when applied to electronic design.

At ARM TechCon3 I will present this Friday a talk on “Increasing Software Development Productivity with ARM and Synopsys Modeling Solutions”. The main theme will be that all models have their limitations and that users have to be thoughtful how to apply them. Specifically, I will talk about the eight main characteristics for choosing models, especially when used for software development in virtual platforms or on FPGA prototypes (which can be considered as yet another “model”, even though they are considerably “more real”):

• Time of Availability: Once the specifications for a specific design are frozen, the time it takes for models to become available directly determines how long software developers will have to wait before starting on the project.
• Execution Speed: Ideally models provide an accurate representation of how fast the real hardware will execute. For software regressions, execution that is faster than real time can be beneficial.
• Accuracy: The type of software being developed determines how accurate the underlying models have to be to represent the actual target hardware, ensuring that issues identified at the hardware/software boundary are not introduced by the development method itself.
• Production Cost: The cost of models is comprised of both the actual cost of production, as well as the overhead cost of bringing up hardware/software designs within it. The production cost determines how easy a development method can be replicated to furnish software development teams.
• Bring-up Cost: Any required activity needed to develop models outside of what is absolute necessary to get to silicon can be considered overhead. Often the intensity of the pressure that software teams face to get access to early representations of the hardware determines whether or not the investment in bring-up cost is considered in order to create positive returns.
• Debug Insight: The ability to analyze the inside of a design, i.e. being able to access signals, registers and the state of the hardware/software design, is a very important model characteristic to enable debug.
• Execution Control: During debug, it is important to stop the models of the target hardware using assertions in the hardware or breakpoints in the software, especially for designs with multiple processors in which all components have to stop in a synchronized fashion.
• System Interfaces: If the target design is an SoC, it is important to be able to connect the models to real-world interfaces. For example, if a USB interface is involved, for verification and software development it is important to connect the development method to real USB protocol stacks. Similarly, for network and wireless air interfaces, connection of the design representation to real world software is important to execute software development.

The talk will be at ARM TechCon3 on Friday, 10/23, at 10:00am in the MCUs & Tools track. I am looking forward to meeting you there to discuss this further.

I will also be available on the exhibition floor on Wednesday and Thursday to present our Virtual Platform solutions and the connections to the ARM Fast Model Enablement program, through which ARM and Synopsys provide a critical mass of models to get closer to the goal of drag and drop assembly of virtual platforms. Enabled through standardization with the SystemC TLM-2.0 APIs, ARM based subsystems containing Fast Models from ARM combined with busses, peripherals and infrastructure components from the DesignWare System-Level Library can be integrated into virtual platforms using the Synopsys Innovator IDE. Together with Synopsys services to enable model customization for peripherals and processors, ARM and Synopsys partner to enable developers to get to virtual platforms with the right combination of models for software development, verification and architecture as early as possible.