I recently found another free tool (in addition to LASI) that allows users to play around with CMOS layout (and some very basic simulation). The tool is from Microwind Inc with the lite version aptly named “Microwind“. Once the user form is filled out with minimal information, unhealthy various tools can be downloaded with an assortment of papers including a 4-bit microprocessor example. The lite version of the tool is somewhat limited, but there are some simple layout examples. Furthermore, this is the tool used to demonstrate all of the examples in Basic CMOS Cell Design (Amazon) and Advanced CMOS Cell Design (Amazon) by Sicard (author of the software) and Bendhia. I have read most of the first book and am working on the second one and will write a short review when both are completed. So far, the first (Basic) one is all-right for a reference but requires some thinking to understand a few of the layouts. The image above is a example layout for a 3-bit DAC.