A Low-Cost, Expandable PXI-Based Solution for Mixed-Signal ASIC Test
Print
Cal-Bay designed control software with two NI PXI-6552 modules to help develop a flexible verification system to test mixed-signal ASICs.
The Challenge
Developing a flexible test system for characterizing new application-specific integrated circuits (ASICs).
The Solution
Implementing a PXI-based system complete with software written in NI LabVIEW to easily expand channel count using the NI Synchronization and Memory Core (SMC) architecture and high-speed digital instruments.
A semiconductor startup company challenged National Instruments and Cal-Bay Systems to develop a verification platform to test its mixed-signal ASICs. Debugging and characterizing a new ASIC is an iterative process, and delays associated with running custom tests on traditional automated test equipment (ATE) can result in unacceptable time-to-market delays.
We used LabVIEW software and PXI hardware to develop custom characterization systems that would previously have been difficult to create. We used several NI PXI-6552 high-speed digital I/O (HSDIO) modules to create a custom scan-chain test system to rapidly debug an ASIC design.
The key requirement in this application was to give test engineers the ability to quickly define digital waveforms to generate and compare against. The customer wanted to use text files to accomplish this task. As such, the system software used native LabVIEW file I/O libraries to read millions of vectors from text files. We used the NI-HSDIO driver libraries to implement the digital waveform generation and hardware compare features on the PXI-6552 for real-time bit comparison of the acquired data. Hardware compare reduces the overhead associated with the comparison task through the use of an onboard field-programmable gate array (FPGA) with software calls through the NI-HSDIO driver. We can make these comparisons with no coding or very little postprocessing.
Another main factor driving the costs in ATE hardware is channel count. Generally, more channels drive the cost of a data acquisition system higher. By using the modular approach of NI products, we can easily add more channels through additional instruments, and with NI T-Clock technology for timing and synchronization, we can easily synchronize all of the instruments with minor modifications to existing hardware and software.
After we completed the development phase for 20 digital I/O channels, the customer expressed desire to use the same software architecture with 40 channels. We completed the upgrade flawlessly thanks to NI T-Clock technology on the hardware front using two PXI-6552 modules.
Because the original software design incorporated modular architecture principles, adding extra channels was a relatively minor task. LabVIEW native software libraries and free drivers reduced the time and risk associated with the usual software development process. In addition, NI SMC technology helped to easily introduce additional instruments and delivered high performance.
– N.D. Smith and M. Cem Karahan
Cal-Bay Systems
Get more information about the advanced digital stimulus/response features of the PXI-6552 module.
This article first appeared in the the Q1 2008 issue of Instrumentation Newsletter.
Print
Reader Comments | Submit a comment »
Legal
This material is protected under the copyright laws of the U.S. and other countries and any uses not in conformity with the copyright laws are prohibited, including but not limited to reproduction, DOWNLOADING, duplication, adaptation and transmission or broadcast by any media, devices or processes.