Online information, tools and references to complement Esperan training classes. You may also be interested in the Esperan tutorial section - freely downloadable PDF's on current and emerging languages and technologies.
Tools and Reviews
jGRASP (reviewed)
Free parsing and folding text editor with VHDL mode and Control Structure Diagram (CSD) intended to improve readability of source code.
Regex Coach (reviewed)
The Regex Coach is a great interactive application to help learn, create and debug Regular Expressions (Regex), used in many languages such as Perl and Tcl as well as being a key component of many UNIX utilities.
LFSR Testbench
Small application for creating Linear Feedback Shift Registers (LFSR's) up to 16 bits in length with automatic generation of HDL code. Xilinx have a great application note XAPP052 (PDF) describing the background and application of these very useful circuits.
GHDL - Free VHDL Linux Simulator
Free, open-source VHDL simulator for Linux released under the GNU license.
SymphonyEDA
Fully-featured, low cost VHDL tool suite, including simulator, Graphical User Interface, waveform viewer, project manager and language-sensitive editor. There is a free restricted version useful for learning VHDL.
BlueHDL Simulator
Download a free Student version of the Blue Pacific BlueHDL simulator for VHDL, Verilog and SystemC. Unfortunately this software is now only available for Windows95, 98 and NT.
FreeHDL Project
Project to create a free VHDL simulator for Linux under the GPL license.
Open Source HDL Tools
Listing of open-source tools from SourceForge.
Doxygen
Superb documentation system for C++, C, SystemC and other object-oriented languages. Creates an online, fully linked graphical represention of any source code automatically, making it a great tool for extracting the code structure of unknown or undocumented code. See it in action with the SystemC2.1 release.
VHDL to HTML Converter
VHDLDOC is a tool to generate automatically hyperlinked html-documentation of VHDL code. Not quite as sophisticated as the Verilog HTML convertor below, and with some strict coding conventions, but useful for exploring undocumented or unfamiliar code.
Verilog to HTML Converter
Cool Verilog documentation tool which turns Verilog code into HTML pages. Includes linked hierarchial references, color syntax highlighting, signal/object tracing and index of design objects.