The XJIO board is an expansion unit that enables you to improve the test coverage for a Unit Under Test (UUT) by verifying the signals right through to the external connections. It will integrate with your XJTAG test system to provide access to otherwise inaccessible areas of your circuit.

With a range of digital and analogue I/O pins on the board, you can improve fault isolation, verify power rail levels, and dispense with costly custom test jigs – even for non-JTAG boards.

XJIO Board
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Improve the test coverage for a Unit Under Test

  • Improve reliability of your boards by increasing analogue and digital test coverage
  • Reduce your debug time by enhanced fault isolation
  • XJTAG can reduce the cost and complexity of your custom test jigs
  • Reach your devices on non-JTAG boards with ‘Black box’ testing
Improve the test coverage for a Unit Under Test


  • 208 digital I/Os with user-configurable voltage range – 1.8V to 3.3V (5V tolerant)
  • On-board 8 channel ADC and DAC, controlled using JTAG
  • Fully expandable to meet your needs
  • Switches and LEDs for user interaction
  • ‘Black box’ testing for non-JTAG boards
  • Reusable, replacing costly custom test jigs
  • Standard IDC connectors
  • USB or 12V power supply
  • RS232 / UART

Digital I/O

With 208 bidirectional digital I/Os, the XJIO board has been developed for maximum connectivity. The I/Os are all 5V tolerant. The default logic level is 3.3V, or you can re-configure the I/Os, in blocks of 16, to use any user-generated voltage between 3.3V and 1.8V.

Analogue Testing

The XJIO board has 16 analogue I/Os (8 inputs and 8 outputs). These are all controllable via the JTAG interface. The on-board 3.3V ADC devices enable basic analogue measurements – e.g. testing a power rail is within limits. The 3.3V DACs allows for UUT analogue inputs to be stimulated, improving test coverage of the target board.

RS232 interface

This interface can be used to further improve test coverage. There is a UART capable of communication up to 230KBaud and a RS232 transceiver that can be driven directly from the JTAG chain.


If more I/Os are required, the XJIO boards can be daisy-chained together via the reconfigurable external JTAG connector to reach the required density. All the connectors on the XJIO board are standard IDC, for economical and efficient cable assemblies.

Power Supplies

You can power the XJIO board from USB, for quick and portable test setup. Alternatively, if you need more than 80mA of current, there is a connector for a standard 12V power supply.

User Interaction

The switches and LEDs enable additional test control, allowing you to develop a complete and repeatable test solution.


You can use the XJIO board with the whole XJTAG product range.

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