.. _general_standards_overview:

=================
General standards
=================

Overview
========

General standards are intended to cover methods which may be used in EPDA
for multiple purposes. They include :ref:`data format<openepda_data_format>`,
:ref:`format for analytic expressions<analytic_expressions>` and vocabulary of standard terms.


openEPDA data format
====================
The data is the core of the EPDA. The data may be numeric or analytic,
tabular or scalar, may originate from measurements, analysis, or physical
simulations, and may include metadata. The data format we standardize
on is a serialization format which allows representing all of these in a
similar form.

The format is used to represent e.g. building block performance data in
the PDK (both in tabular numeric form and as compact models), measurement
data resulting from a PIC testing / characterization, etc.

See more details on :ref:`openepda_data_format`.


Analytic expression format
==========================

In many cases, coordinates, sizes, locations, and other numeric
values can be represented as real numbers. However, often an analytic
expression which is evaluated at runtime is more convenient. openEPDA defines
a standardized analytic expression format, which can be used anywhere where
a numeric value is expected.

Example use cases are parametric building blocks (positions of it's pins
may be functions of the length / width), compact models for
building block performance (i.e. functional dependencies instead of
tabulated numeric values).

See more details on :ref:`analytic_expressions`.


Vocabulary of standard terms
============================

Most of the data files in the EPDA are represented as sets of
`attribute-value pairs <https://en.wikipedia.org/wiki/Name%E2%80%93value_pair>`_.
The vocabulary defines a list of the standard attributes, with
their meaning, allowed value type, dimensionality, etc.

The vocabulary is currently under development.