Digital IC design, design methodology and electrical engineering
An article about log file naming? Well, somebody’s got to do it, because so few software tools get it right.
CAD software runs a long time in batch mode, so the log file is often the users’ sole feedback. When running a flow, I constantly check progress by listing the log files with the ls command. Repeatedly. All day. Their names and their sort order matter. More
You might hope that error messages will rarely appear, but whenever your program or design flow does output an error message, users will try to interpret its every nuance. Depending on how they react to messages, enormous amounts of time can be saved or wasted. The tragedy is that good messages are actually quite inexpensive–they consume little run time or memory, they require no exotic algorithms. More
It was during my first job as a computer technician in high school that I developed the maxim: first check power, then check clocks. More
At DAC 2011 I gave a presentation on the architecture of oaScript at Si2’s OpenAccess Scripting Language Workshop.
Many people think that the RioMagic package/chip co-design tool was killed after Magma acquired Rio Design Automation in 2007. I did too. In fact it lives on, as Zuken RioMagic.
Chip design is an iterative process. The design flow is run repeatedly as it is extended and refined into a program that can automatically build the entire chip. Your flow needs software to make sure that only the necessary steps are executed, in the correct order, on the correct data. Different hierarchical blocks must be constructed similarly, yet differently.
This is one of a series of articles on simple, specific techniques that will make your chip design flow easy to use. In this installment, I will explain how to control your chip design flow, and rules to keep it organized. More
When a user wants chip design data, a script or a log file, how do they find it? They look at the file and directory names. In fact, this may be the only documentation available.
As an IC design flow architect, proper file naming is the most important thing you can do to guide your users to the data they need. Further, you need to use safe names that can be used without transformation for any purpose, on any computing platform. More
When you read an SDC file from the command line, it works fine. When you read it using a Tcl procedure, it won’t work, because the global variables cannot be accessed. Here’s how to fix this annoying problem.
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This is an old, old post, but over the years it continues to be one of my most popular pages. I leave it here in the hope that it is still useful. Please add your corrections or comment. –John
It is good design practice to use as few SDC files as possible. This post describes a way to create a single SDC file that can be used both before and after clock tree synthesis (CTS), and by both Cadence PKS and SoC Encounter. More
