Accessory to Ruggedize
Boundary-Scan Test Hardware
for Vital Applications
The Corelis ScanTAP-IsoPod is an add-on
accessory that provides a complete electrical isolation barrier
between the target system and the JTAG Test Access Port (TAP).
It provides electrical isolation of the JTAG controller TAP
signals from the unit under test and enhances the protection of
the equipment against harsh electrical environments. The digital
isolation offered by the
ScanTAP-IsoPod protects boundary-scan
controller hardware from ground potential differences that are
often present in production floors and in other industrial
environments. The ground potential differences are especially
harmful when using computer powered USB based test and
measurement equipment where the computer and the target system
are powered from different AC power lines sources in a noisy
While the Corelis boundary-scan controllers are highly robust
and reliable, their use is often extended to harsh environment
conditions and where isolation is required between the
boundary-scan controller and the target system. While electrical
isolation often limits the performance of the equipment on both
sides of the isolator, the
ScanTAP-IsoPod was designed with high
speed in mind, supporting test clocks with rates up to 40 MHz.
The ScanTAP-IsoPod is a drop in replacement for most of the
Corelis TAP cables as it utilizes the standard 20 pin universal
Corelis TAP connector pinout and it eliminates signal stress
that might be caused by ground loops or voltage/ground potential
mismatches in the test setup.
useful on the manufacturing line to prevent an entire
line from going down when a controller is damaged and
for development where untested targets pose the highest
risk of damaging the target. It is compatible with
Corelis ScanExpress boundary-scan and functional test
tools and most Corelis boundary-scan controllers. The
current global economic condition is stressing our
clients’ limited budgets and we are committed to develop
products that reduce their test costs.
Prevent time loses due to
manufacturing lines and development grinding to a halt when
a boundary-scan controller is damaged.
Cut costs from repairing test
machines, controllers, and targets due to damage.
Limit damage to the
boundary-scan controller caused by operator error.
Simple to use, the
ScanTAP-IsoPod is functionally transparent so no changes to the
hardware test setup are needed.
Compatible with all Corelis
boundary-scan controllers without the need for custom test
Who can benefit from using
ScanTAP-IsoPod is useful on the manufacturing line to
prevent an entire line from going down when a controller is
damaged and for development where untested targets pose a
Customers who currently own Corelis ScanExpress
boundary-scan and functional test tools.
ScanTAP-IsoPod is compatible with most Corelis boundary-scan
ScanTAP-IsoPod Performance and Features
ScanTAP-IsoPod provides a
hardware environment with higher fault tolerance. The following list itemizes some of IsoPod's features:
4 kV isolation barrier helps
prevent damage to hardware
3.3 V TAP interface
Supports JTAG test clock (TCK)
frequencies up to 40 MHz
Supports I2C and SPI
programming speeds up to 1 MHz
Compatible with Corelis
Compatible with the ScanExpress™
family of boundary-scan
and functional test products
Standard Corelis 20-pin TAP
ScanTAP-IsoPod Installation and Usage
The Corelis ScanTAP-IsoPod module connects to Corelis
boundary-scan controllers through a 20-pin flat ribbon cable.
External power is required and the required 5V power supply is
ScanTAP-IsoPod System Connection Diagram
There are two 20-pin connectors on
the ScanTAP-IsoPod. The connector marked Controller connects to
the Corelis boundary-scan controller and the connector marked
Target connects to the target unit under test (UUT).
ScanTAP-IsoPod product consists of the following components:
Corelis P/N ASF4020100
Manual (pdf version)
Two 20-pin to 20-pin TAP
Cables (12”), Corelis P/N 15312-2
5V Power Supply, Corelis
Power Cord, Corelis P/N
The following optional interface cables are also
available from Corelis:
20-pin to 20-pin TAP Cable
(8”), Corelis P/N 15312-1
20-pin HD (high-density) to
20-pin TAP Cable (12”), Corelis P/N 15392-2
20-pin HD (high-density) to 20-pin TAP Cable (8”),
Corelis P/N 15392-1
Connecting to the Controller and the Target
Corelis ScanTAP-IsoPod module connects to Corelis boundary-scan
controllers and to targets through a 20-pin flat ribbon cable.
The top view of the 20-pin controller connector (0.100” x 0.100”
spacing), including the pin numbering, is shown in the
ScanTAP-IsoPod 20-pin Controller Connector diagram
ScanTAP-IsoPod 20-pin Controller Connector (top view)
The ScanTAP-IsoPod power must be supplied by the included 5V
power supply provided by Corelis (Corelis P/N 4000-05V4A1R3MM).
The power supply must be plugged into the same outlet or power
strip as the host PC.
Test Setup Integration
The procedure for integrating the
ScanTAP-IsoPod into an
existing test setup or a new one is simple. There are three
major components to the test setup: (1) a Corelis boundary-scan
controller, (2) a ScanTAP-IsoPod unit, and (3) a target UUT.
Follow the instructions below to integrate the
into a test setup. The images below shows a typical test setup
where the ScanTAP-IsoPod is placed in series between the
controller and the UUT.
Test Setup Using
Aside from ground loop prevention, the
provides additional advantages in the testing environment. The
ScanTAP-IsoPod’s isolation circuitry adds additional tolerance
against overvoltage and excessive current. This protection is
useful to prevent damage to the controller from a user
accidentally connecting the TAP cable backwards into the target.
It will also help prevent damage from shorts caused by
manufacturing defects or other operator errors. Development is
also a common environment to use extra protection where the
operational results have not yet been verified on untested
Typical ScanTAP-IsoPod Application
Pin Connection Diagram
ScanTAP-IsoPod with ScanExpress Tools
The ScanTAP-IsoPod module is compatible with ScanExpress Runner,
ScanExpress Debugger and ScanExpress Programmer. For more
information on these software tools,
USB-1149.1/E Controller Configuration Screen in
Datasheet if you would like to learn more about
For additional information, please refer to
Corelis Application note # 09-0106.
To speak with a
Sales Engineer, please click here.