vcd-parser

A Node.js parsing tool for Value Change Dump (VCD) files and generating a readable JSON document. It can be used with different hardware simulation tools such as Icarus Iverilog.

Installation

npm install --save vcd-parser

Usage example

``javascript
const VCDParser = require('vcd-parser');
VCDParser.parse(

$date
Tue Feb 12 14:01:15 2019
$end
$version
Icarus Verilog
$end
$timescale
1ns
$end
$scope module test_tb $end
$var reg 1 ! clk $end
$var wire 1 " rst $end
$upscope $end
$enddefinitions $end
#0
$dumpvars
0"
0!
$end
#15
1"
#20
1!
#40
0!
#60
1!
#80
0!
#100
1!
#115

)
.then(parsedData => {
console.log(parsedData);
// {
// "date": "Tue Feb 12 14:01:15 2019",
// "version": "Icarus Verilog",
// "timescale": "1ns",
// "endtime": "115",
// "scale": "1ns",
// "signal": [
// {
// "type": "reg",
// "size": 1,
// "refName": "!",
// "signalName": "clk",
// "module": "test_tb",
// "name": "test_tb.clk",
// "wave": [
// [
// "0",
// "0"
// ],
// [
// "20",
// "1"
// ],
// [
// "40",
// "0"
// ],
// [
// "60",
// "1"
// ],
// [
// "80",
// "0"
// ],
// [
// "100",
// "1"
// ]
// ]
// },
// {
// "type": "wire",
// "size": 1,
// "refName": "\"",
// "signalName": "rst",
// "module": "test_tb",
// "name": "test_tb.rst",
// "wave": [
// [
// "0",
// "0"
// ],
// [
// "15",
// "1"
// ]
// ]
// }
// ]
// }
})
.catch(err => {
console.error(err);
});
``

API Documentation

- VCDParser :
- [.parse(content, [opts], [cb])](#VCDParser..parse) ⇒ Promise.<ParsedData>

$3

Parse VCD text content and generate a valid JSON representation.
The function returns a promise unless a callback is provided.

Returns: Promise.<ParsedData> - that resolves with the parsed data

| Param | Type | Default | Description |
| ------- | ------------------------------------------------------- | --------------- | ------------------------------------------------------- |
| content | string | | The text content of the VCD file |
| [opts] | Options | {} | Optional configuration to customize the parsing process |
| [cb] | ParseCallback | | Optional callback if you don't prefer to use promises |

$3

The optional configuration for the VCD parser

Properties

| Name | Type | Description |
| ----------------- | -------------------- | ----------------------------------------------------------------------------------------------- |
| compress | boolean | Compress the output wave by ignoring the unchanged values |
| expandAmbigousBus | boolean | If the bus has some ambigous value (z or x), it gets expanded to represent the whole bus signal |

$3

The parsed VCD object generated by the parser

Properties

| Name | Type | Description |
| --------- | ------------------------------------------------------- | -------------------------------------------------------------------- |
| [...meta] | string | The values of different initial meta-data, e.g. date, timescale..etc |
| endtime | string | The endtime of the simulation |
| scale | string | The time-scale unit of the simulation |
| signal | Array.<Signal> | The signal values of the simulation |

$3

The object representing one signal data

Properties

| Name | Type | Description |
| ------- | ----------------------------------------------------------------- | -------------------------------------------------------- |
| name | string | The full name of the signal |
| type | string | The type of the signal, e.g. wire, reg,..etc |
| size | number | The size/width of the signal in bits |
| refName | string | The reference for this signal used inside the VCD file |
| module | string | The name of the top module for which this signal belongs |
| wave | Array.<SignalValue> | The values of the signal at different points of time |

$3

The value of a signal at a specific point of time, represnted as a tuple [time, value]

Properties

| Name | Type | Description |
| ---- | ------------------- | ------------------------------------- |
| 0 | number | The time of the event |
| 1 | number | The value of the signal at that event |

$3

The callback for the parsing function.

| Param | Type | Description |
| ---------- | ------------------------------------------------- | ----------------------------------------- |
| err | error | The error generated while parsing |
| parsedJSON | ParsedData | The JSON document generated by the parser |