TCL Scripting VSD Workshop

Overview

This repository contains course materials, lab exercises, and scripts from TCL VSD Workshop focused on mastering TCL scripting. The content is aimed at enabling automation in digital design flows by providing hands-on examples in TCL scripting, Yosys-based RTL synthesis, and Quality of Results (QOR) generation.

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Key Learning Outcomes

• Master TCL scripting
• Automate constraint file generation (CSV, SDC to OpenTimer)
• Integrate TCL with Yosys for RTL synthesis and memory module generation
• Perform hierarchical design checks and error detection
• Generate and analyze QOR metrics including WNS (Worst Negative Slack) and FEP (False Path)

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Module-wise Documentation

Module	Description
Module 1	Introduction to TCL and VSDSYNTH Toolbox Usage
Module 2	Variable Creation and Processing Constraints from CSV
Module 3	Processing Clock and Input Constraints
Module 4	Complete Scripting and Yosys Synthesis Introduction
Module 5	Advanced Scripting Techniques and Quality of Results Generation

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Tools Required

• TCL Development Suite
• Yosys synthesis tool
• OpenTimer for timing analysis

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TCL Syntax used in the course

Tcl Syntax	Description
set var value	Assigns a value to a variable.
$var or ${var}	Retrieves the value of a variable.
puts "text"	Prints text to the console, followed by a newline.
puts -nonewline "text"	Prints without adding a newline.
open filename mode	Opens a file in a given mode: "r" (read), "w" (write), "a" (append). Returns file handle.
close fileHandle	Closes an open file.
gets fileHandle var	Reads a line from file into var. Returns -1 at EOF.
read fileHandle	Reads the entire contents of a file.
glob -dir path *.ext	Lists files matching a pattern (e.g., all .v files) in a directory.
foreach var list {}	Iterates over each item in a list.
proc name {args} {body}	Defines a procedure with name, arguments, and body.
return	Exits the current procedure and returns to caller.
[expr {...}]	Evaluates an arithmetic or logical expression.
incr var ?amount?	Increments variable by 1 or optional amount.
lindex list index	Retrieves the item at a specific index from a list.
llength list	Returns the number of elements in a list.
lsearch list pattern	Finds index of first element in list matching pattern.
lsearch -all -inline list pattern	Returns all matching elements in a list.
lappend list_var value	Appends a value to the list.
split string sep	Splits a string into a list using a separator.
join list sep	Joins a list into a string using separator.
lsort -unique list	Sorts a list and removes duplicates.
regexp pattern string	Returns 1 if regex pattern matches string.
regexp -all -- pattern string	Returns number of matches of pattern in string.
regsub pattern string replacement	Replaces first match of pattern. Use -all for all.
string match pattern string	Checks if string matches pattern (supports wildcards).
string map {pattern replacement} string	Replaces all pattern occurrences in string.
[command args]	Executes a command and returns its result.
exec command	Executes an external shell/system command.
catch {script} resultVar	Runs script, stores error flag in resultVar.
exit	Terminates the script immediately.
source filename	Executes another Tcl script from a file.
format formatStr args	Formats strings like C’s printf (e.g., %04d).
# comment	Comment line — ignored by interpreter.
::namespace::command	Calls a command from a specific namespace.
array set arr {key val ...}	Initializes an associative array.
array get arr	Returns key-value pairs from the array.
switch -- $var { case {...} }	Matches value to defined cases. Use -glob for patterns.
file exists path	Checks if a file exists.
file isdirectory path	Checks if a path is a directory.
file normalize path	Converts path to full normalized form.
[file dirname path]	Extracts the directory from a file path.
[file tail path]	Gets the filename from a path.
time {script} count	Measures execution time of script repeated count times.
lassign list var1 var2	Assigns values from a list to variables.
"\n" or "\\n"	Newline character in strings.
&> or >& (in exec)	Redirects both stdout and stderr to a file.

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Acknowledgements

I extend my sincere gratitude to Mr. Kunal Ghosh, VSD for sharing his profound expertise throughout the workshop.