Waveform-analysis tool speeds complex-IC validation
-- EDN, July 6, 2000
Integrated Measurement Systems' IMS-Waves on Vanguard waveform-analysis tool could do even more than the company's tester hardware to simplify the jobs of IC-design and product engineers. IMS' IC-validation testers are unlike typical IC automatic-test systems (Picture). The IMS systems allow quick reconfiguration, a capability that design and product engineers especially prize. However, the testers operate more slowly than do production testers and hence cost less. The ideas behind this hardware-design philosophy are that test throughput is not an issue in design validation and that those who don't need high throughput shouldn't have to pay for it. Prices for the so-called big D (for digital), little A (for analog) complex-IC testers start at $700,000, including IMS-Waves on Vanguard.
The new software adds more capabilities tailored to the needs of engineers who characterize devices and troubleshoot manufacturing- and test-process problems. These capabilities include a simulation display of waveforms the device under test should be producing, a timing-diagram display of signals the tester should be producing, a logic-timing-analyzer-like display of signals the device is actually producing, and an oscilloscopelike display of actual analog waveforms from the device.
The tester builds the analog displays by repetitively sampling the signals and varying the comparator's reference voltage with each new sample. The simulation-display tool includes an automatic pattern translator that currently accepts inputs from Verilog and generic simulators and will soon also accept inputs from IMS' DVT (digital-virtual-test) tools. To simplify finding errors, you can time-align the simulator display with the timing-diagram display. On bidirectional pins, the timing-diagram display uses arrows in user-configurable colors to indicate the direction of signal flow.
The software can store waveforms from a golden device for comparison with waveforms from the current device under test. This capability is especially valuable to quality-assurance and product engineers. Another capability that should help engineers track down failure-producing conditions is the ability to define waveform patterns and search through long records for them.
Integrated Measurement Systems, 1-503-626-7117, www.ims.com.
at www.rscahners.ims.ca/ednmag
—by Dan Strassberg
