Add sync signal validation #9

	name: CI Verification

	on:
	push:
	branches: [main]
	pull_request:
	branches: [main]

	jobs:
	verify:
	runs-on: ubuntu-24.04
	timeout-minutes: 15

	strategy:
	matrix:
	video_mode:
	- VGA_640x480_72
	- VGA_800x600_60
	fail-fast: false
	max-parallel: 2

	steps:
	- name: Checkout repository
	uses: actions/checkout@v4
	with:
	fetch-depth: 1

	- name: Install dependencies
	run: \|
	sudo apt-get update -qq
	sudo apt-get install -y --no-install-recommends \
	verilator \
	libsdl2-dev \
	python3 \
	make \
	g++

	- name: Check Verilator version
	run: verilator --version

	- name: Cache Verilator build artifacts
	uses: actions/cache@v4
	with:
	path: \|
	obj_dir
	build/nyancat-frames.hex
	build/nyancat-colors.hex
	key: verilator-${{ runner.os }}-${{ matrix.video_mode }}-${{ hashFiles('rtl/*/.v', 'rtl/*/.vh', 'sim/*/.cpp') }}
	restore-keys: \|
	verilator-${{ runner.os }}-${{ matrix.video_mode }}-

	- name: Lint Verilog code
	run: \|
	verilator --lint-only -Wall -Wno-fatal \
	-DVIDEO_MODE_${{ matrix.video_mode }} \
	-Irtl rtl/vga-sync-gen.v rtl/nyancat.v rtl/vga-nyancat.v

	- name: Build simulation
	run: make build VIDEO_MODE=${{ matrix.video_mode }}

	- name: Run verification
	run: make check VIDEO_MODE=${{ matrix.video_mode }}

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