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XJTAG is a global, market leading provider
of boundary scan solutions.
Our products are used by hardware engineers
around the world in design, development
and manufacture to reduce costs
throughout the product lifecycle.
The XJTAG Development System
consists of three main applications.
XJAnalyser is a graphical
debugging application, which allows you
to interact in real time
with the JTAG devices on your boards.
XJDeveloper is a powerful application
that allows you to check connections
not only between your JTAG devices,
but also your non-JTAG devices.
XJRunner provides you with an easy-to-use
graphical interface for running the tests
that are exported from XJDeveloper.
These three products together,
make up the XJTAG Development System.
When you have Ball Grid Array
or BGA devices on a board,
fault-finding gets very difficult.
There are hundreds of connections
all hidden under here,
where you can't see them,
can't get to them and can't test them.
XJTAG can help you see exactly what's happening,
without lifting the device from the board.
The XJTAG Development System
comes with an installation CD,
USB cable, XJLink2 and a demo board.
The XJLink2 provides the connection
between the USB and the JTAG chain.
The XJDemo board is used in the tutorials
that come with the system.
It has two JTAG devices
and several non-JTAG devices
and will be used in most of the following examples.
I have already installed XJTAG onto my PC.
All I need to do now
is connect the XJLink2 to my demo board
and plug the USB cable into my PC.
XJAnalyser is a fantastic tool
if you are looking to debug a fault with a board.
With virtually no setup required, XJAnalyser gives you
a graphical representation
of the devices in your JTAG chain.
As soon as you start the scan,
XJAnalyser automatically shows
the values of the pins on those devices.
From the Colour Legend
you can see that red means high,
blue is low, yellow is oscillating
and black is for linkage pins
such as power or JTAG connections.
If anything causes the value
of one of these pins to change,
its colour will change in real time
to highlight that change.
If you are working with BGA devices,
the lack of physical access
means that this is the easiest way
to check the value of a pin.
You can Monitor Changing Pins in the
Pin Watch window, at the bottom of the screen.
You can also use XJAnalyser
to drive values out onto the board
by simply double clicking on a pin.
The pin whose value has changed
has automatically been added to the Watch window,
where you can see,
on the right of the highlighted line
that it is Outputting.
I am now going to zoom in
on the BGA device on the left.
Here the pin is connected to an LED.
We are now going to set this pin to toggle slow
so you can see the LED flashing on the demo board.
It has also been added to the Watch window
as we are still monitoring changes on our board.
I am now going to disable that pin.
If I set another pin, E4 to toggle,
you will notice that D3 has started to toggle
at the same time.
If you suspect that you have a short under a device,
this a great way to confirm it.
Again, both E4 and D3 have been added
to the Watch window.
From the Watch window we can easily locate the pin
by using the Goto function.
This is particularly useful
on a larger board with many more devices.
Setting pins to a particular value,
or setting them toggling
is a very effective way of confirming faults,
or verifying connections between devices.
Here we have a board with 8 JTAG devices.
The screen can be split to see different views.
This allows you to view different parts of the chain
at the same time. You may want to scroll down
to see the devices further down the chain,
or zoom in on one area of particular interest.
XJTAG can save you time and money
when developing hardware, debugging prototypes
and later in production.
To find out more or to take a free trial,
contact sales@xjtag.com