Tips, links and resources.
http://home.europa.com/~celiac/ver_eda.html
The ERC32 VHDL models consists of fully functional, timing accurate VHDL models of the SPARC integer unit, floating-point unit and memory controller.
http://www.estec.esa.nl/wsmwww/erc32/docs.html
Example simple Verilog program
http://www2.latech.edu/~acm/helloworld/verilog.html
VHDL filter design, pole-zero demo, MOS calculator
http://www.ee.oulu.fi/electronics/
A high-level processor specification language. it views a processor as a machine that executes a set of instructions. syntax, image, functionality (side-effect), resource-usage and timing of each instruction are described in a hierarchical form.
http://www.cse.iitk.ac.in/sim-nml/
Provides Verilog, VHDL, TDML, logic analyzer, pattern generator, and SPICE tools.
http://www.syncad.com/
A fast VHDL Compiler/Simulator [Freeware].
http://www.symphonyeda.com/products.htm
SEAMS is a mixed-signal simulator for models written in the VHDL-AMS language
http://www.ececs.uc.edu/~dpl/