The JTAG standard contains definitions for various different types boundary scan cells, each of which have different capabilities, and these allow an IC vendor to accurately describe how the pins on their chips behave. But because not every eventuality can be foreseen the JTAG specification also allows IC vendors to create their own types of [...]
(This article has now been replaced by an updated version, here.) […]
Until now, XJRunner tests have been limited to functions which have no input arguments and a single return argument (which returns the result). XJTAG v3.5 relaxes that restriction, allowing input in XJRunner tests, though there is still a requirement to have a single return argument for the result. […]
Alongside other improvements to the XJRunner test setup, XJTAG v3.5 has a new interface to specify bus access from the test system using the XJRunner Setup screen. When you edit a test there is now a Bus Access tab on the dialog, which allows full control of which pins are used to read and/or write [...]
It has always been possible to construct tests in XJEase which were conditional on something else having happened, or a previous test having passed, but the new v3.5 release includes a number of major enhancements to the setup, running and control of tests in XJDeveloper and XJRunner, some of which make conditional testing much easier to [...]
This post is an update to the original “Debugging Connection Test (part 1)” post – over time several features in XJTAG have changed considerably and may be hard to find by following my original post. […]
Recently one of our newer customers started on their first solo board setup. They had previously seen XJTAG demonstrated and had also had their initial board setup done by an XJTAG engineer. When they came to setting a board up for themselves they tried to follow the path that the XJTAG engineer had talked them [...]
Transistors are one of the things we get asked about quite a bit: “How should I categorise the transistors in my project?” […]
1149.6 testing is coming of age, and though XJTAG has supported IEEE Std. 1149.6 since software version 2.1 (released in 2008) it seems to us that 1149.6 devices are becoming much more common in the last couple of years. […]
‘Dynamic Chains’ is a term we’ve coined to describe a test system that has the ability to drive more that 1 JTAG chain configuration. This may be possible if it has multiple chains driven by different TMS or TCK pins, or a single chain that has multiple JTAG device variations (for example using a Scan Bridge). Before v3.3, XJTAG projects [...]