‘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 could only represent a single static JTAG chain. With our new functionality, multiple JTAG chain variations can be defined, set up and run within a single XJTAG project in a single test run. […]
When using JTAG with a Device Under Test (DUT) connected to a bed-of-nails test fixture, often little attention is paid to the way the JTAG signals are wired. This article (published in SMT magazine last year) gives a helpful explanation of why it is important to get this right, and gives tips for best practice.