Issue link: https://iconnect007.uberflip.com/i/1457913
86 DESIGN007 MAGAZINE I MARCH 2022 respins. You'll have validated, tested data that you know works, and validated designs that you know work. And the PDK interfaces well with the tools we use, such as the HyperLynx and Xpedition systems from Siemens EDA. Now let's look at an example of an application of an FHE PDK for a flexible row driver that's turning on each call of the temperature sensor array, one by one, sequentially so that the read- out circuitry and IO number can be shared and the pin count minimized. e graph on the le of Figure 3 was generated using the HyperLynx simulation tool. e design artwork and layout are ported into the tool, which simulates what the data is expected to be at different ports or different pins in the design. is allows us to accurately model and modify our designs to meet the requirements we want. is repre- sents the intended, ideal model of the system and how it should act. e graph on the right shows the measured data of that same system. It reveals that the intended behavior is represented very accu- rately. It's so accurate because we're using the FHE PDK. In other words, we're using vali- dated, tested models when we're running the simulation. If we didn't have the PDK, then we could still achieve these results, but it would require a lot more cycle time. We'd have to go through multiple redesigns and potentially feed all that measured data into the simulation to refine it to get to this level of results. With the FHE PDK, all you do is pull out the known components, the known modules, into your design, simulate it, and you know you're going to get a manufacturing result that matches your simulation. FHE PDK DRC Now let's examine how we use the PDK for design rule checking (DRC). For DRC, we can import a design. Let's say we just finished a new layout for a new FHE design. It's a great device, with a lot of different sensors and LEDs, and we want to see if we can manufacture it. Let's say we want to manufacture it at the NextFlex facil- ity using a screen print. We'd load up the DRC, load in the rule check for screen print, and we'd run it, and the DRC would do all the hard work. It will generate the violation report if there's any violations. It will tell us if the vias are too close, if it's below the minimum spacing allowed, or if a trace is too thin or too thick. And it makes it easy to see what design changes are needed, if any, to run it through a specific manufacturing process. It can be run for any of the printing processes: screen print, inkjet, extruded, etc. Overall, we see that the PDK plays an instru- mental role in reducing the amount of time and Figure 3: Expected and actual behavior of an FHE.