Digital Design Methodology

At Plextek, we like to keep things as simple as possible. We understand that you require products that perform technically. However, we also fully understand the commercial pressures such as keeping down NRE costs, time to market and product cost.

When we embark on a development with you, we will ascertain what are the key drivers for your project. We will work with you in order to make the appropriate design decisions. You will find that our methods are very open, ideally so that we can achieve a mutual trust at an early stage for the benefit of the project. Plextek's client relations philosophy places a great deal of importance on achieving customer satisfaction. This is shown in our performance in winning repeat business.

In order to manage the design, we use effective tools that allow us to communicate throughout the development to those involved. In particular, Plextek adopt a system solution strategy to develop the appropriate solution for your specific needs

In very many cases, digital signal processing is a part of the solution. To Plextek, DSP is a function. We are able to identify its performance requirements and take into account other major factors such as cost, power consumption, client preferences, etc, in order to choose appropriate technologies for realising a practical system solution.

Our normal design flow is initiated with achieving a thorough understanding of the requirement. In parallel with this, an outline architecture for the solution is drafted. As the outline architecture evolves test strategies are developed. Subsequently the outline architecture is developed using top down, followed by bottom up techniques to develop into the implementation.

Our preferred design entry utilises hierarchical decomposition, which can only be performed effectively with a sound and effective knowledge of the capabilities of the target silicon. After the architecture of a device is identified to sufficient detail, we are able to code the leaf levels of the design, with VHDL our preferred language.

Our typical test strategy starts by performing functional unit testing to an appropriate level utilising logic simulators. We then integrate blocks into functional units, and again prove via simulation. Finally, we perform device level simulations and ideally prove the design in functional hardware. We have experience of a wide range of test and development solution strategies.

For typical product developments, Plextek will design PCB level products in parallel with the device designs. One very major advantage of programmable systems is that they can be tested in-situ at a very early stage. We recognise this and use it to great advantage. With ASIC and FPGA/PLD developments, the risk of a design flaw is the same, however the impact is very much greater with an ASIC. It is very cost effective to implement a relatively immature design quickly in programmable logic and run it in the laboratory. Very many more test vectors are run in real time on real hardware than in any simulator. Granted, there may not be as much control, but it is a tradeoff. We do however have the power of the simulation tools to identify the causes of problems after we have identified symptoms.

In some cases, we have generated sign-off test vectors from the simulations and used them for development and/or production sign-off of PCB level hardware.

In most cases, we adopt a synchronous design style. This allows us to concentrate our simulation efforts on functional verification. Timing closure is performed using static path techniques and tools.

Our methods have been proven over many years of digital logic and system design. We are always willing to devise new flows to meet particular requirements, for example safety critical designs. Please contact us with your requirements.

Back to the Programmable Design page.