How to handle multiple boundary scan chains

Posted on November 1, 2019

That’s an easy one. With onTAP’s TAP CONNECT JTAG Controller, you can run an unlimited number of chains simultaneously. Each TAP CONNECT JTAG Controller has two channels which provides the opportunity to run two chains at once. Furthermore, additional chains are handled with ease by additional Controllers. In fact, there are no restrictions on the number of chains running together using onTAP and the TAP CONNECT JTAG Controller.

Each Controller conveniently connects to USB ports with off-the-shelf A-to-mini USB cables and industry-standard fly leads or ribbon cables are used to connect to your board.  These components are included with each TAP CONNECT JTAG Controller. To meet the requirements of lower voltage boards, Flynn Systems offers both a Low Voltage Controller and a Low Voltage/Low Impedance Controller. The different voltage ranges are:

Standard Controller

The standard high-speed Controller operates at 1.8 to 5.0 DVC.

Low Voltage

This Controller operates at 0.99 to 3.6 VDC. It works the same as the standard Controller but is more stable for handling lower voltages.

Low Voltage/Low Impedance

While the Low Voltage/Low Impedance Controller is similar to the low voltage Controller, this Controller supports the 50 Ohm pull-up and pull-down resistors and common TDI/TDO pin connections for multiple chains, all found in Intel’s Core i7 and Atom applications. In addition, this Controller can operate at variable voltages and that makes it perfect for use with Intel’s Core i7 and Atom applications.

If you’re still unsure about which Controller is right for you, don’t hesitate to contact Flynn Systems for help. We’ve got experts on boundary scan available to show how you can make boundary scan testing as simple and straightforward as possible.