# Synthesis

## Preparing design

In /home/debian/OpenLane/designs create a subdirectory named counter.
In the counter directory create a subdirectory src and copy counter.v to the src directory.
The most important file, besides the source files, is config.json.
Create the file config.json with a below configuration.

```
{
    "//": "Basics",
    "DESIGN_NAME": "counter",
    "VERILOG_FILES": "dir::src/*.v",
    "CLOCK_PERIOD": 10,
    "CLOCK_PORT": "clk",
    "//": "PDN",
    "PL_TARGET_DENSITY": 0.45,
    "//": "Pin Order",
    "//": "Technology-Specific Configs",
    "pdk::sky130*": {
        "FP_CORE_UTIL":20,
        "CLOCK_PERIOD": 10,
        "scl::sky130_fd_sc_hs": {
            "CLOCK_PERIOD": 8
        },
        "scl::sky130_fd_sc_ls": {
            "MAX_FANOUT_CONSTRAINT": 5
        }
    },
    "pdk::gf180mcu*": {
        "CLOCK_PERIOD": 24.0,
        "FP_CORE_UTIL": 40,
        "MAX_FANOUT_CONSTRAINT": 4,
        "PL_TARGET_DENSITY": 0.5
    }
}
```

## Running a flow

You can run command from below to generate ASIC from Verilog code.

```bash
./flow.tcl -design counter
```

## Results

The main and most important result is ASIC generated in GDSII. Besides you can find metcis.csv in /home/debian/OpenLane/designs/counter/runs/RUN_2024.05.04_23.34.47/reports/.

Use `klayout` to see GDSII of counter.

```bash
klayout designs/counter/runs/RUN_2024.05.04_23.34.47/results/final/gds/counter.gds
```

![Quartus](layout.png)

Metrics can be imported by LibreOffice Calc.

![Quartus](metrics.png)

Check the file to see the most interesting parameter like a frequency and a chip's area.