chip__ADV7513-Example__Verilog___pattern_vg___112318f044/testbench/tb_response.txt

```python
#!/usr/bin/env python3
"""
Testbench for pattern_vg module.
"""

import random
import sys
from pathlib import Path

import cocotb
from cocotb.clock import Clock
from cocotb.triggers import RisingEdge, FallingEdge, Timer
from cocotb_tools.runner import get_runner


@cocotb.test()
async def test_reset(dut):
    """Test that reset clears the internal ramp_values register."""
    # Create clock
    clock = Clock(dut.clk_in, 10, units="ns")
    cocotb.start_soon(clock.start())
    
    # Apply reset
    dut.reset.value = 1
    await RisingEdge(dut.clk_in)
    await RisingEdge(dut.clk_in)
    
    # Check that control signals pass through
    dut.vn_in.value = 1
    dut.hn_in.value = 0
    dut.dn_in.value = 1
    await RisingEdge(dut.clk_in)
    assert dut.vn_out.value == 1, "vn_out should follow vn_in"
    assert dut.hn_out.value == 0, "hn_out should follow hn_in"
    assert dut.den_out.value == 1, "den_out should follow dn_in"
    
    # Release reset
    dut.reset.value = 0
    await RisingEdge(dut.clk_in)
    
    # Set pattern to 4 (RAMP) and check initial behavior
    dut.pattern.value = 4
    dut.ramp_step.value = 256  # 1.0 in 8.12 fixed point
    dut.x.value = 0
    dut.y.value = 0
    dut.dn_in.value = 1
    await RisingEdge(dut.clk_in)
    
    # With pattern 4 and x=0, dn_in=1, ramp_values should be set to ramp_step
    # Output should be ramp_values[19:12] = 256 >> 12 = 0
    assert dut.r_out.value == 0, f"r_out should be 0 after reset, got {dut.r_out.value}"
    assert dut.g_out.value == 0, f"g_out should be 0 after reset, got {dut.g_out.value}"
    assert dut.b_out.value == 0, f"b_out should be 0 after reset, got {dut.b_out.value}"


@cocotb.test()
async def test_pattern_border(dut):
    """Test pattern 1 (border) functionality."""
    clock = Clock(dut.clk_in, 10, units="ns")
    cocotb.start_soon(clock.start())
    
    # Initialize
    dut.reset.value = 1
    await RisingEdge(dut.clk_in)
    dut.reset.value = 0
    await RisingEdge(dut.clk_in)
    
    # Set display parameters
    dut.total_active_pix.value = 640
    dut.total_active_lines.value = 480
    
    # Set pattern to border
    dut.pattern.value = 1
    dut.dn_in.value = 1
    dut.r_in.value = 0x12
    dut.g_in.value = 0x34
    dut.b_in.value = 0x56
    
    # Test top border (y=0)
    dut.x.value = 100
    dut.y.value = 0
    await RisingEdge(dut.clk_in)
    assert dut.r_out.value == 0xFF, f"Top border should be white, got {dut.r_out.value}"
    assert dut.g_out.value == 0xFF, f"Top border should be white, got {dut.g_out.value}"
    assert dut.b_out.value == 0xFF, f"Top border should be white, got {dut.b_out.value}"
    
    # Test left border (x=0)
    dut.x.value = 0
    dut.y.value = 100
    await RisingEdge(dut.clk_in)
    assert dut.r_out.value == 0xFF, f"Left border should be white, got {dut.r_out.value}"
    assert dut.g_out.value == 0xFF, f"Left border should be white, got {dut.g_out.value}"
    assert dut.b_out.value == 0xFF, f"Left border should be white, got {dut.b_out.value}"
    
    # Test right border (x = total_active_pix - 1)
    dut.x.value = 639
    dut.y.value = 100
    await RisingEdge(dut.clk_in)
    assert dut.r_out.value == 0xFF, f"Right border should be white, got {dut.r_out.value}"
    assert dut.g_out.value == 0xFF, f"Right border should be white, got {dut.g_out.value}"
    assert dut.b_out.value == 0xFF, f"Right border should be white, got {dut.b_out.value}"
    
    # Test bottom border (y = total_active_lines - 1)
    dut.x.value = 100
    dut.y.value = 479
    await RisingEdge(dut.clk_in)
    assert dut.r_out.value == 0xFF, f"Bottom border should be white, got {dut.r_out.value}"
    assert dut.g_out.value == 0xFF, f"Bottom border should be white, got {dut.g_out.value}"
    assert dut.b_out.value == 0xFF, f"Bottom border should be white, got {dut.b_out.value}"
    
    # Test non-border area
    dut.x.value = 100
    dut.y.value = 100
    await RisingEdge(dut.clk_in)
    assert dut.r_out.value == 0x12, f"Non-border should pass through r_in, got {dut.r_out.value}"
    assert dut.g_out.value == 0x34, f"Non-border should pass through g_in, got {dut.g_out.value}"
    assert dut.b_out.value == 0x56, f"Non-border should pass through b_in, got {dut.b_out.value}"


@cocotb.test()
async def test_pattern_moirex(dut):
    """Test pattern 2 (moireX) functionality."""
    clock = Clock(dut.clk_in, 10, units="ns")
    cocotb.start_soon(clock.start())
    
    # Initialize
    dut.reset.value = 1
    await RisingEdge(dut.clk_in)
    dut.reset.value = 0
    await RisingEdge(dut.clk_in)
    
    # Set pattern to moireX
    dut.pattern.value = 2
    dut.dn_in.value = 1
    
    # Test with odd x (LSB = 1)
    dut.x.value = 5  # binary 101, LSB = 1
    dut.y.value = 10
    await RisingEdge(dut.clk_in)
    assert dut.r_out.value == 0xFF, f"Odd x should be white, got {dut.r_out.value}"
    assert dut.g_out.value == 0xFF, f"Odd x should be white, got {dut.g_out.value}"
    assert dut.b_out.value == 0xFF, f"Odd x should be white, got {dut.b_out.value}"
    
    # Test with even x (LSB = 0)
    dut.x.value = 4  # binary 100, LSB = 0
    await RisingEdge(dut.clk_in)
    assert dut.r_out.value == 0x00, f"Even x should be black, got {dut.r_out.value}"
    assert dut.g_out.value == 0x00, f"Even x should be black, got {dut.g_out.value}"
    assert dut.b_out.value == 0x00, f"Even x should be black, got {dut.b_out.value}"
    
    # Test with dn_in = 0 (should output black regardless of x)
    dut.dn_in.value = 0
    dut.x.value = 5  # odd x
    await RisingEdge(dut.clk_in)
    assert dut.r_out.value == 0x00, f"With dn_in=0 should be black, got {dut.r_out.value}"
    assert dut.g_out.value == 0x00, f"With dn_in=0 should be black, got {dut.g_out.value}"
    assert dut.b_out.value == 0x00, f"With dn_in=0 should be black, got {dut.b_out.value}"


@cocotb.test()
async def test_pattern_ramp(dut):
    """Test pattern 4 (RAMP) functionality."""
    clock = Clock(dut.clk_in, 10, units="ns")
    cocotb.start_soon(clock.start())
    
    # Initialize
    dut.reset.value = 1
    await RisingEdge(dut.clk_in)
    dut.reset.value = 0
    await RisingEdge(dut.clk_in)
    
    # Set display parameters
    dut.total_active_pix.value = 10  # Small value for testing
    dut.dn_in.value = 1
    
    # Set pattern to RAMP
    dut.pattern.value = 4
    dut.ramp_step.value = 4096  # 1.0 in 8.12 fixed point (1 << 12)
    
    # Start at x=0, should set ramp_values to ramp_step
    dut.x.value = 0
    dut.y.value = 0
    await RisingEdge(dut.clk_in)
    # ramp_values = 4096, output = 4096[19:12] = 4096 >> 12 = 1
    assert dut.r_out.value == 1, f"At x=0, r_out should be 1, got {dut.r_out.value}"
    assert dut.g_out.value == 1, f"At x=0, g_out should be 1, got {dut.g_out.value}"
    assert dut.b_out.value == 1, f"At x=0, b_out should be 1, got {dut.b_out.value}"
    
    # Move to x=1, should