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Comment by williadc | Hacker News Reader

Tcl is more-or-less required if you're involved with the physical design of silicon (most EDA tools only provide a Tcl interface). It's a good fit for that purpose. If you need a language which is easy to embed and you want non-programmers to be able to use it, Tcl is a good choice, though I've heard that Lua has supplanted Tcl for that purpose.

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That's been my job for the last 30 years.

Our flow is thousands of lines of Tcl code around all the cadence and synopsys tools. Then we write more Tcl to create the power grid, create blockages, etc.

In the silicon industry it’s definitely tcl only. Zero Lua. But every tcl script I have seen is extremely simple, often just a bunch of commands to the EDA tool that reads like a list of bash commands.

I'd say python starts to make some strides, likely due to the AI hype train. But it's still mostly Tcl.

Tcl scripting gets more interesting when you want to talk to a design running in an FPGA over JTAG. I have a toy CPU project which I've so far tested on Altera/Intel, Xilinx and Lattice FPGAs, and a debug interface where a C-based ncurses debugger connects over TCP/IP to a Tcl bridge which talks to the appropriate JTAG interface for the particular type of chip.

I'm also a big fan of the full-fat Tk-capable Tcl in Altera's SignalTap / Virtual JTAG - I used it recently to plot histograms on-demand for profiling RAM / Cache accesses.

That's one of the benefits of tcl, having a bunch of commands require as little syntax as possible.

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