SEMI EDA/Interface A Standards Overview

The Equipment Data Acquisition (EDA, also known as Interface A) standards are a collection of SEMI standards intended to facilitate and improve communication between a factory's data gathering software applications and the factory equipment. The factory uses EDA to collect specific data from equipment, and then analyze that data to determine how best to increase productivity, improve quality, and reduce costs. (For an in-depth look at 10 topics related to EDA and EDA implementation, please click here.)

EDA does not replace the SEMI GEM/SECS standards (E4, E5, E30, and E37) or the SEMI GEM300 standards (E39, E40, E87, E90, E94, E116, E148, and E157), since EDA does not provide any features for equipment control or configuration. Instead, equipment suppliers support EDA in addition to other required interfaces.

Relationship to SECS/GEM

During 2009 and 2010, IC makers started requiring integrated EDA solutions from the equipment suppliers. Since then, the demand has continued to increase as IC makers roll out plans to improve yield and equipment utilization.

EDA Freeze Versions

Because the EDA standards continue to evolve and change, ISMI and its member companies have initiated the concept of freeze versions. A freeze version allows equipment suppliers to develop new systems that can be installed into factories, and allows IC makers to develop new data-gathering client applications, while SEMI continues to develop the EDA standards. Each freeze identifies a specific version of the individual EDA standards (E120, E121, E125, E128, E132, E134, E138, and E147) that equipment suppliers and IC makers use as a unified set to implement the interface. The industry adopted the initial ISMI 1105 freeze version in 2006, and then, four years later, ISMI announced a new 0710 freeze version that includes many improvements and some new capabilities.

SEMI adopted the freeze version concept by creating two downloadable bundles of standard schema files: one for the 1105 freeze version and another for the 0710 freeze version. These are available on the SEMI website.

This page offers a brief overview of EDA/Interface A SEMI standards. For more information, download the Cimetrix Introduction to SEMI EDA Standards white paper.

SEMI EDA/Interface A Standards

Cimetrix was at the forefront of the EDA/Interface A standards development, and continues to be dedicated to support the development and use of those standards. We collaborated with SEMATECH  to develop the EDA Client Connection Emulator to support Freeze Version I (1105), and then for Freeze Version II (0710). Today, Cimetrix offers ECCE Plus, which supports both versions of the EDA standards.

EDA/Interface A is comprised of multiple SEMI standards all of which are available for download from the SEMI website. The following four are the primary SEMI standards:

  • E120 Specification for the Common Equipment Model (CEM)
  • E125 Specification for Equipment Self Description (EqSD)
  • E132 Specification for Equipment Client Authentication and Authorization
  • E134 Specification for Data Collection Management
  • E164 Specification for EDA Common Metadata

Both equipment and factory client applications implement interfaces via web services using SOAP/XML messages over HTTP or HTTPS connections, and those interfaces must comply with the specific SOAP/XML implementations standards E120.1, E125.1, E132.1, and E134.1.

EDA/Interface A Client Operations 

EDA/Interface A Operations Flow

  • Initially, each client must establish an authenticated session.
  • Next, the client can ask for the Equipment Model metadata (for an in-depth look at this topic, please view the video "E164 - EDA Common Metadata") information to see what data is available through EDA
  • With this information client can define and activate data collection plans.
  • The Equipment will continue to generate Data Collection Reports until the client deactivates the plans or becomes unavailable.
  • When shutting down properly, the client should close the session.

Mapping EDA/Interface A to SECS/GEM 

EDA (Interface A) uses many of the same concepts as SECS/GEM. Here is a mapping between the similar concepts and technologies.

SECS/GEM EDA/Interface A
Status Variables, Equipment Constants, and Data Variables Parameters
Alarms Exceptions
Collection Events (S6, F11) Events in DCP
E39 Objects SEMIObjType and Instance IDs
Trace Data Collection Traces in DCP
Reports Data Collection Plans/Reports
State Machines State Machines
Enable/Disable Collection Events ActivatePlan/DeactivatePlan
Define and Link Reports (S2, F33 and S2, F35) DefinePlan


Comparing EDA/Interface A With SECS/GEM

SECS/GEM EDA/Interface A
SECS/GEM supports only one client connection. IC makers cannot run several data gathering applications at the same time without an infrastructure to share the data. EDA requires support for multiple concurrent clients.
SECS/GEM is only partially self-describing and therefore relies on good documentation. IC makers have complained that the documentation is often not well-maintained. EDA is self-describing through the E125 standard's metadata.
SECS/GEM data is relatively flat and unorganized. The IC Maker must study the documentation, hardware, software, and processing to understand how to organize the data. EDA presents the data in a hierarchy, organized by the major hardware components.
Data in a SECS/GEM message is highly structured and relatively inflexible. Because EDA uses XML, it is inherently designed to accommodate additional metadata.
SECS/GEM is used extensively in only a few industries, which limits the number of experts in the world. SOAP/XML and HTTP are the backbone of most Internet and Intranet applications. There are many programmers worldwide that are familiar with this technology.
In most factories, the SECS/GEM interface is used for equipment configuration and control, and therefore subject to extensive oversight and lengthy change procedures. It can take at least several weeks for any data collection changes to be implemented. EDA is independent of the GEM interface and therefore immediately available for the dynamic data collection needs of the process engineers.


EDA/Interface A Freeze Versions I and II

Unless the client and equipment are implementing the same version of the EDA standards, they cannot fully communicate and might be incompatible. This is the nature of SOAP/XML Web Services technology. In 2006, ISMI announced Freeze Version 1105 of the EDA standards in order to ensure the interoperation of equipment and client software implementations.

This version, Freeze Version I, includes the following standards:

Standard Document Revision Schema Namespace Version WSDL Namespace Version
E120 Common Equipment Model 1104 E120-1.V1104 N/A
E125 Equipment Self-Description 1105 E125-1.V0305 E125-1-V0305
E132 Client Authentication and Authorization 1105 E132-1.V0305 E132-1-V0305
E134 Data Collection Management 1105 E134-1.V1105 E134-1-V1105
E138 Common Components 0305 V0305 N/A

In 2010, ISMI announced a new Freeze Version of the EDA standards known as the 0710 Freeze Version or Freeze Version II. This defined the specific version of each of the individual EDA standards that should be used by equipment manufacturers to create an EDA interface.

Freeze Version II includes the following standards:

Standard Document Revision Schema Namespace Version WSDL Namespace Version
E120 Common Equipment Model 0310 E120-1-V0310 N/A
E125 Equipment Self-Description 0710 E125-1-V0710 E125-1-V0310
E128 Specification for XML Message Structures 0310 E128-1-V0706 N/A
E132 Client Authentication and Authorization 0310 E132-1-V0310 E132-1-V0310
E134 Data Collection Management 0710 E134-1-V0710 E134-1-V0710
E138 Common Components 0709 E138-1-V0305 N/A

Equipment suppliers need to ensure they implement the version of the standard that is implemented on the client side at the manufacturing site.

EDA/Interface A Terminology and Acronyms

Term Definition
Access Control List (ACL) Part of E132, the Client Authorization details that grant or deny Client sessions and impose restrictions on Clients access to specific Interface A information and operations.
Client Consumer An Interface A Client that receives the Data Collection Reports and other E134 consumer operations.
Data Collection Plan (DCP) Part of E134, a data gathering request that includes a set of Events (with a configurable set of Parameters), Exceptions (with a fixed set of Parameters), and Traces (with a configurable set of Parameters). After successfully creating a Data Collection Plan, it must be activated. Then the Client will receive the respective Data Collection Reports as configured in the plan.
Data Collection Report (DCR) The Equipment sends the requested data in this standard format.
EDA Equipment Data Acquisition, also known as Interface A. The combination of SEMI standards E120, E125, E128, E132, E134, E138, and E164.
Equipment Equipment refers to the hardware and software received from equipment suppliers to perform work for the IC maker. In some context of Interface A, Equipment refers to the Interface A Server that represents the hardware and software to the Clients.
Freeze Version A stable set of guidelines for implementing SEMI EDA/Interface A standards. There are currently two freeze versions:
  • 1105, commonly referred to as Freeze Version I
  • 0710, commonly referred to as Freeze Version II
Host The software an IC maker is running to communicate with the Equipment. A host typically refers to the SECS/GEM connection but could also refer to a client using Interface A.
Metadata Information that describes the data, such as when an Event occurs or the interpretation of a Parameter's value.
Operation An Interface A transaction, method, or message initiated by an Interface A client or server. Each operation has a name, well-defined format, and meaning. E125, E132, and E134 each define a set of operations for the client and server.
Parameters The set of data available for gathering from the Equipment's Interface A connection.
Session Also called an Authenticated Session, a session is established between the Server and Client by following the E132 procedures. Once a session is established, the Client can send authorized operation messages.
SOAP Simple Object Access Protocol (SOAP): In order to make the Interface A standards easier to implement, they use the SOAP protocol. It is a lightweight, XML-based protocol for exchange of information in a decentralized, distributed environment. See for more information.

For more EDA terms and acronyms, download the Cimetrix Introduction to SEMI EDA Standards white paper.

E164: Enabling Consistent Metadata

The new SEMI E164 standard, approved in July 2012, provides a single, agreed, interpretation of the various SEMI standards as represented in a common metadata definition (for an in-depth look at this topic, please view the video "E164 - EDA Common Metadata"), which will help drive consistency in how equipment suppliers implement the EDA standards. The Common Metadata will help remove some of the uncertainty that may have prevented many companies from developing host-side client applications that can use the EDA data produced by the equipment.

EDA developers may download and use the Freeze I (1105) version of the Metadata Conformance Analyzer and the Freeze II (0710) version of the Metadata Conformace Analyzer.

To support equipment integration into the fab, the EDA interface can provide descriptions of the equipment's structure and behavior to the factory control systems. These metadata sets include the equipment components, the events and exceptions that can be reported, and all the available data parameters. A predictable and reliable interface definition enables faster equipment integration and lower installation cost.

Testing EDA/Interface A Connectivity

EDA developers may download and use both the EDA 1105 freeze version and the EDA 0710 freeze of the Metadata Conformance Analyzer at the MCA.