Trying to verify Verilog/VHDL designs with formal methods and tools

vhdl verilog assertions formal yosys systemverilog sva

T. Meissner 4adea23c43 Fix chformal selection parameter; add reset restrict to top-level		4 years ago
alu	Use PSL functions instead of workarounds; add forgotten always to asserts in alu	5 years ago
counter	Use PSL functions instead of workarounds; add forgotten always to asserts in alu	5 years ago
fifo	Add simple FIFO model incl. formal tests	4 years ago
vai_fifo	Fix chformal selection parameter; add reset restrict to top-level	4 years ago
vai_reg	Use PSL functions instead of workarounds; add forgotten always to asserts in alu	5 years ago
.gitignore	Makefile: add clean target; fixed Reset_n_i port dir in alu_t.sv	6 years ago
LICENSE.md	Inital commit	6 years ago
README.md	Fix chformal selection parameter; add reset restrict to top-level	4 years ago

README.md

The original repository is located on my own git-server at https://git.goodcleanfun.de/tmeissner/formal_hw_verification

It is mirrored to github with every push, so both should be in sync.

formal_hw_verification

Tests and examples of using formal verification to check correctness of digital hardware designs. All tests are done with SymbiYosys, a front-end for formal verification flows based on Yosys.

All stuff in the master branch uses ghdl-yosys-plugin and GHDL as VHDL front-end plugin for (Symbi)Yosys. Using GHDL as synthesis frontend allows using PSL as verification language. The alu, counter & vai_reg designs can be verified with that combination at the moment.

Some examples in the verific branch use the commercial VHDL/SystemVerilog frontend plugin by Verific which isn't free SW and not included in the free Yosys version. See on the Symbiotic EDA website for more information.

alu

A simple ALU design in VHDL. The formal checks contain various simple properties used by assert & cover directives which are proved with the SymbiYosys tool.

counter

A simple counter design in VHDL. The testbench contains various simple properties used by assert & cover directives which are proved with the SymbiYosys tool.

fifo

A simple synchronous FIFO with various checks for write/read pointers, data and flags.

vai_fifo

A simple FIFO with valid-accept-interface. Consists of fifo as sub-unit and some glue logic doing fifo<->vai interface conversion. This design serves as an example how to verify designs with sub-units containing formal checks.

vai_reg

A simple register file with VAI (valid-accept-interface) which serves as test design to try formal verification of FSMs.