JTAG Technologies, a leading world-wide provider of IEEE std. 1149 compliant boundary-scan products, has introduced the JT 2111/MPV Digital I/O Scan (DIOS) module. The module retains a legacy form-factor and default settings but adds programmable voltages to facilitate the enhanced testing of complexprinted circuit boards.

When connected to a circuit board via edge connector or fixture test pins the module enhances regular interconnect tests by exercising the board's connections in synchronisation with native boundary-scan components. What's more, the module features PLDs (Programmable Logic Devices) and a 10MHz oscillator, so can be programmed to perform more custom functional and pattern tests.

James Stanbridge, JTAG Technologies' Sales Manager UK, comments: "The JT 2111/MPV DIOS DIMM Test Module provides a 'best-of-both-worlds' solution when it comes to implementing boundary-scan and functional tests. For example, a target circuit board may contain elements, such as board-edge connectors and non-boundary-scan logic clusters, which cannot be accessed directly by boundary-scan. In such cases, the overall testability of the board is compromised, allowing some manufacturing faults to go undetected. The DIOS module overcomes this problem by extending the reach of boundary-scan to include the testing of circuit board edge connectors and by providing extra test points internal to the PCB to improve fault coverage."

In addition, the module's hot-swap feature offers improved test throughput by allowing test targets to be connected/disconnected from the fixture without cycling power.

100% backward compatibility with previous versions is ensured by simulation of the former DIOS devices. What's more both output and input thresholds can be programmed to 1.5, 1.8, 2.5 or 3.3V making the module
ideally suited to testing modern low-voltage logic families. The I/O channels are grouped into blocks of 16 channels and, to reduce scan chain length and improve test efficiency, any number of 16-channel
groups can be bypassed.

Selected channels can be interfaced with custom cabling to the board under test (low volume apps) or interfaced with bed-of-nails fixtures for higher volume production. The I/O channels are individually programmable as input, output, bi-directional or tri-state signals.

Up to 10 JT 2111/MPV DIOS modules can be daisy-chained together to provide a massive 640 I/O channel count.

Stanbridge concludes: "The JT 2111/MPV DIOS is extremely versatile and offers a low-cost and modular method for adding JTAG compliant I/O to any test strategy. Moreover, they're manufactured and supported by the market-leading and longest-established boundary-scan company in the business."

The JT 2111/MPV DIOS is available immediately from JTAG's UK sales office.