如何在YosysJS中使用write_json命令生成Verilog的JSON描述

Hey there! Since you're already comfortable with Yosys commands and have the RTL visualization flow working in YosysJS, generating the JSON description is just a matter of adding the right Yosys command to your ys.run() sequence.

The Core Command: write_json #

In standard Yosys, you use the write_json command to export the design's structural description as JSON. This works exactly the same in YosysJS—you just need to integrate it into your existing command pipeline, then read the output file using YosysJS's file utilities.

Modified Code Example #

Here's how to adjust your existing code to generate and retrieve the JSON output:

// Write your input Verilog to a temporary file
ys.write_file("input.v", document.getElementById("code").value);

// Run Yosys commands: reset design, read Verilog, synthesize, export JSON
ys.run("design -reset; read_verilog input.v; synth; write_json output.json");

// Read the generated JSON file
const designJson = ys.read_file("output.json");

// Use the JSON as needed—print to console or display on page
console.log("Design JSON:", designJson);
// Example: Display in an HTML element with id "json-output"
document.getElementById("json-output").textContent = designJson;

Customize the Synthesis Stage #

You don't have to run the full synth flow if you don't want to. If you need the JSON for a specific intermediate stage (e.g., pre-synthesis, after coarse synthesis), adjust the command sequence to match your needs:

• Pre-synthesis (only parsed/elaborated design):

  design -reset; read_verilog input.v; hierarchy; proc; write_json pre-synth.json
  

• After coarse synthesis (matching your existing RTL flow):

  design -reset; read_verilog input.v; synth -run coarse; write_json coarse-synth.json
  

Key Notes #

• YosysJS mirrors standard Yosys command behavior—any command you'd run in the Yosys CLI can be passed to ys.run().
• Use ys.read_file() to retrieve the output JSON file, just like you used it to read the show.dot file for SVG generation.

内容的提问来源于stack exchange，提问作者Aidar