Test-and-measurement giant Agilent Technologies (Palo Alto, Calif.) is debuting what it says is the semiconductor test industry's first high-speed production tester for identifying the maximum number of product defects at the lowest cost. Agilent's BIST Assist 6.4 enables signal integrity testing of high-speed serial links operating as fast as 6.4-Gbits/s.
The BIST Assist 6.4 product uses a loopback/BIST (built-in self-test) approach. An extension to Agilent's 93000 SOC Series of scalable testers, the company claims that BIST Assist 6.4 will deliver cost savings in excess of 50% over conventional at-speed production approaches.
Existing Test Tradeoffs
To date, testing devices with high-speed links has forced a compromise. Conventional at-speed test approaches of automated test equipment (ATE) and bench instruments offer the highest fault coverage, but at a price that's typically too high for volume manufacturing of cost-sensitive, consumer-driven products.
On the other hand, loopback testing offers low cost but doesn't provide adequate defect identification. With adjustable and precise jitter injection, DC access and at-speed level control, this approach can provide insights during production tests.
Agilent claims that its BIST Assist 6.4 offers the best of both worlds: the fault coverage of ATE, at the low cost associated with loopback test. "BIST Assist 6.4 can revolutionize the way companies conduct high-speed interface test," avows Tom Newsom, VP of Agilent Technologies and general manager of Agilent's SOC Business Unit.
Newsom adds that BIST Assist 6.4 provides a unique high-volume test approach for interfaces such as PCI Express, Serial ATA, Fibre Channel and Serial RapidIO. These interfaces are pervasive in current and future-generation media PCs, disk drives, set-top boxes, and digital video recorders.
The key feature that differentiates Agilent's approach is the ability to split the device test into test pattern generation and a Pass/Fail decision, in addition to signal integrity validation. While the device in loopback mode provides the pattern generation and pass/fail information, BIST Assist adds real world stress (i.e., adjustable jitter injection) to the signal, which exercises the link performance.
In addition, BIST Assist permits level programming together with level detection to verify the at-speed level performance of the device. Other features include common-mode detection, common-mode signal injection, and DC or low speed vector access.
BIST Assist 6.4 provides adjustable jitter injection (up to 430-ps), exercising high-speed link performance and expanding fault coverage, with BIST Assist 6.4 calibrated within a test head. Here's a table summarizing the system's specs.
Click for larger table of specs
These capabilities can be used to test graphics ICs, chipsets, switches, and SERDES (serial-de-serializer) devices in BIST or loopback mode (e.g., SATA, PCI-Express and Fibre Channel) that require high-fault coverage and high-speed data rates at the lowest cost in production.
Each BIST Assist 6.4 card provides four loops (16 differential pins) operating up to 6.4-Gbits/s. Each loop contains a programmable differential receiver and driver (4-pin equivalent), and a high-speed delay line that provides the jitter injection. An on-board sinewave generator modulates the jitter signal, or as an alternative, an external source can be used.
DC or low-speed vector boards can be routed into the BIST Assist board to provide connectivity for DC and/or scan resources. That means that existing DC or scan channels can be used and connected without additional relays on a system's loadboard.
In addition, a BIST Assist setup tool provides a graphical user interface that ensures rapid test-program creation and implementation.
With BIST Assist, an Agilent 93000 tester for PCI Express costs about $995,000. It provides full test capability for a PCI Express bridge device requiring 64 pins at 6.4-Gbits/s, and up to 256 digital pins at 400-Mbits/s, as well as requisite software, support, and services.
For more information, contact Agilent Technologies, Automated Test Group, 815 SW 14th St., Loveland, Colorado 80537. Phone: 970-679-3399.
Or, visit Agilent's BIST Assist Web site for more details.