Scripting languages such as Tcl can help you automate design-for-test processes.
Have you ever wanted an enhancement from an EDA (electronic design automation) tool but couldn't wait the months or years for delivery of the improvement? Of course you have. Wouldn't it be great if you could take matters into your own hands and put together a script to accomplish the task? I believe you'd also respond "yes." Many EDA tools let you script your own, and now Mentor’s DFT tools do too. In case you haven’t heard about it yet, it’s called the Tessent Shell platform.
Tessent Shell includes a Tcl shell environment and design data model that provides a unified Tcl command set and command naming convention. What does this mean? Basically, Tessent Shell lets you accomplish your DFT (design for test) work by combining DFT tool commands along with Tcl scripting, which gives you powerful capabilities to interact with and even edit the design.
Why did we choose Tcl when there so many other/newer/better scripting languages available? Tcl, which stands for Tool Command Language, was designed to be a general purpose scripting language that could be embedded in any application. Numerous EDA tools use Tcl and have for many years, so it seems to be the de facto industry standard. Because many EDA users have tools from a variety of tool suppliers, using Tcl allows them to have one common tool command language across all their EDA tools. With Tcl, users can integrate different tools together into a design flow.
As I mentioned earlier, Tessent Shell is a platform for running the various Tessent tools. For example, in one tool session you could use Tessent Scan to perform scan test insertion on a design, then switch tools to create combined hybrid TK/LBIST (logic built-in self-test) compression logic. These types of design flows can be scripted for automation and reuse, which helps keep your DFT development time under control. The tool commands meld seamlessly with the Tcl commands to perform whatever tasks you need.
In addition to providing access to the Tessent tools, Tessent Shell lets you manipulate and query your design data. These capabilities are commonly referred to as design editing and introspection, respectively. These functions are very powerful and allow you to make simple or complex design changes easily, without having to leave the DFT environment to make the design changes in a synthesis tool.
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