verification.md

Verification

We run the following verification:

• behavioral-level simulation and testing
• gate-level simulation and testing
• unit-tests for the assembler, and for the test runner scripts themselves

Continuous Integration (CI)

The CI server runs the following verification scripts:

• python: /cicd/run-py.sh.
• behavioral: /cicd/run-behav.sh.
• gate-level simulation: /cicd/run-gls.sh.

Behavioral-level simulation and testing

Concept

We use the iverilog simulator to run simulation of our design at the behavioral level. This is the first stage of verification, since these simulations run fastest, and are easiest to debug.

Pre-requisites

• python3
• iverilog
• have cloned this repo, and be at the root of this repo

Procedure

bash test/behav/run_sv_tests.sh

This will run various behavioral-level unit-tests at /test/behav. The script is /test/behav/run_sv_tests.sh.

bash test/behav/run_examples.sh

• under the hood, this will run many of the examples in examples/direct, and check the outputs against the expected outputs, which are in the paired files, with suffix _expected.txt, in the sub-folder examples/direct/expected folder.

Gate-level simulation and testing

Concept

Gate-level simulation runs on partially synthesized verilog, where the behavioral-level code, such as always blocks and if blocks has been converted into purely combinatorial logic and flip-flops, and then further converted into actual cells, using osu018 technology.

We use yosys to simulate down to cell-level, using asu018 technology, then use iverilog to run simulation of the resulting netlist.

Results

You can view execution of these tests in the CI server linked above.

Pre-requisites

• python3
• yosys
• iverilog
• have cloned this repo, and be in the root of this cloned repo

Procedure

bash test/gls/gls_tests.sh

See test/gls/gls_tests.sh.

Unit-tests for the assembler and some of the test scripts themselves

Concept

The assembler is written in python, as are some of the test scripts, such as for timing. We use pytest to verify these scripts.

Pre-requities

• have python3
• from this repo, have done:
  • pip install -e .
  • pip install -r test/py/requirements.txt

Procedure

pytest -v

Verification guidelines

See docs/verification_guidelines.md.

Coding guidelines

In order to ensure succesful gate-level simulation and tape-out, we have created coding guidelines at docs/coding_guidelines.md