vte

Verification Template Engine is a Jinja2-based template engine targeted at verification engineers. It is designed to make it easy for engineers to leverage a pre-built library of templates for creating content, such as UVM elements (tests, sequences, agents, etc). Also, for engineers to easily create libraries of templates to create custom content.

Getting VTE

VTE is available as a source release on GitHub (https://github.com/fvutils/vte).

• Download a release tarball
• Add the vte-/bin directory to the PATH
• Start creating content!

vte command

VTE usage is shown below:

usage: vte [-h] {generate,list} ...

positional arguments:
  {generate,list}
    generate       generate source files
    list           list available templates

optional arguments:
  -h, --help       show this help message and exit

Environment Variables

The VTE_TEMPLATE_PATH environment variable is used to specify directories that contain templates. The path is colon-delimited.

list command

The list sub-command shows the available templates, along with a brief description.

Example:

% vte list
project.ivpm.googletest-hdl - IVPM project with Googletest-HDL dependence
verif.ip.googletest-hdl     - IP verification environment using Googletest-HDL
verif.uvm.test              - Creates a UVM test class

generate command

The generate sub-command creates template content using the specified template ID.

usage: vte generate [-h] [-force] template name [KEY=VALUE [KEY=VALUE ...]]

positional arguments:
  template    ID of template
  name        Name to use in the template
  KEY=VALUE   Specify other template variables

optional arguments:
  -h, --help  show this help message and exit
  -force      force overwrite of existing files

Example:

% vte generate project.ivpm.googletest-hdl my_proj
Note: processing template etc/ivpm.info
Note: processing template etc/packages.mf
Note: processing template etc/env.sh
Note: processing template scripts/ivpm.py
Note: processing template scripts/ivpm.mk
% find -type f
./etc/ivpm.info
./etc/packages.mf
./etc/my_proj_env.sh
./scripts/ivpm.py
./scripts/ivpm.mk

Template Structure

Elements on the VTE_TEMPLATE_PATH are considered to be repositories of templates. A template is identified based on the presence of a .vte file. All files in the directory containing the .vte file and its subdirectories are assumed to be part of the template.

The template ID is derived from the directory structure between the template-path entry and the directory containing the .vte directory. For example, the .vte file for the built-in template verif.uvm.test is located in the following directory:

verif
  uvm
    test
      .vte

Template Descriptor File

The template descriptor file (.vte file) conforms to Python config-file format. Sections are marked with [<section>], and values within the section are specified using key=value format.

Template Section

The template section specifies global information about the template. This section is optional.

Template Description

The desc entry in the template section specifies the text that will be displayed when the user lists templates using the vte command. If this entry is not specified, the description of the template will be blank.

Example:

[template]
desc = Creates a UVM test class

Parameter Section

Templates can accept parameters beyond the built-in name parameter. A parameters must be declared in the .vte file using a parameter section. The parameter name is specified as part of the parameter section. Example:

[parameter:base_class]
desc = Base class
default = uvm_test

The example above declares a parameter named base_class. The UVM Test template uses this parameter as the name of the base class for the new UVM test.

Parameter Description

A description of the parameter can be specified using a desc entry in the parameter section.

Parameter Default Value

A parameter can be given a default value using the default entry. For example, the base_class parameter has a default of uvm_test.

VTE will issue an error of the user does not provide a value for a parameter that does not have a default value.

Template Files

Template files use Jinja2 format to refer to template parameters. This means that parameters are referenced using {{parameter}} format. Directives are specified using {% directive %} format.

Here is an example of the template for creating a UVM test:

/****************************************************************************
 * {{name}}.svh
 * 
 ****************************************************************************/
{%set filename = "{{name}}.svh" %}
/**
 * Class: {{name}}
 * TODO: Document UVM Test {{name}}
 */
class {{name}} extends {{base_class}};
	`uvm_component_utils({{name}})
	
	function new(string name, uvm_component parent=null);
		super.new(name, parent);
	endfunction
	
endclass

Note how the built-in name parameter is used to form various identifiers in the file. Note, also, how the template-specific base_class parameter is used to specify the base class for the UVM test.

filename directive

By default, VTE will create an output file that has the same name as the template file, and is located at the same relative path in the output directory.

The output file namd and path can be changed using the filename directive. Template variables can be used in the value specified for the filename directive.

The UVM test template above specifies that the output filename will be the same as the name of the UVM test class.

chmod directive

Often, project templates contain scripts that must be made executable. The chmod directive allows a template file to specify the permissions for the output file. By default, files are created using the active umask.

Example: The template for the status script, shown below, uses chmod to specify that the script must be executable.

#!/bin/sh
#****************************************************************************
#* status.sh
#****************************************************************************
{% set chmod = "+x" %}

testname=$1
seed=$2

if test ! -f simx.log; then
  echo "FAIL: $testname - no simx.log"
else
  n_passed=`grep "PASSED: $testname" simx.log | wc -l`
  n_failed=`grep "FAILED: $testname" simx.log | wc -l`

  if test $n_passed -eq 1 && test $n_failed -eq 0; then
    echo "PASSED: $testname"
  elif test $n_failed -ne 0; then
    echo "FAILED: $testname ($n_failed)"
  else
    echo "FAILED: $testname ($n_passed $n_failed)"
  fi
fi

Developing VTE

Building VTE

VTE depends on several other Python packages. Currently, the 'setup.py' for VTE is incomplete, and not really used. Fetch dependent packages as follows: % cd scripts % make -f ivpm.mk

This will fetch Jinja2 and other dependent packages and unpack them in the 'lib' directory

Running VTE in Development Mode

Running VTE in development mode is nearly identical to running it in release mode: run the 'vte' script in the bin directory, which will set PYTHONPATH appropriately.