Inovys Corporation

Stylus™ Tester Operating System and Emulator

Product Description
Stylus is the control software for Inovys Corporation semiconductor automated test equipment (ATE). Prior to first silicon, Stylus can be used by engineers to refine the ATE programs and patterns for production test by connecting to a Verilog simulation in lieu of a device under test.

Stylus directly reads and executes IEEE 1450 Standard Test Interface Language (STIL) without translation or compilation to a proprietary language. The result of this capability is reduced complexity and effort involved in preparing efficient test patterns for ATE. Stylus accomplishes this by providing a standardized means of pattern delivery to Inovys ATE through STIL. Stylus offers a direct link to automated test pattern generation (ATPG) tools. Mentor Graphics' ASIC Vendor Interface (AVI) option for FastScan ATPG produces STIL patterns readable by Stylus without translation.

Stylus also collects device failure data from Inovys ATE and reports it in the formats directly readable by failure diagnosis tools. This makes the diagnosis of device failures possible, rapid, and easy. In particular, Mentor Graphics' FastScan Diagnosis can isolate a defect to the gate-level using failure data collected by ATE. Such failure data must be represented with respect to scan architectures and FastScan syntax in particular. Stylus collects fail data in FastScan format, resulting in a translation-free flow for diagnosis.

When connected through the Verilog PLI to Mentor Graphics' ModelSim, Stylus validates test patterns by emulating the tester hardware. By applying the test patterns to the Verilog model in exactly the same way that the ATE hardware operates and detecting any mismatches or incompatibility, Stylus provides test engineers a high degree of confidence in pattern acceptability before parts become available. . In addition, because Stylus is aware of hardware constraints, test patterns and test programs can be validated for tester applicability and efficiency as well as logical correctness.

Benefits to End User of Product and Interface to MGC

• Shorter time to market through simplified test program generation flow
• Eliminated cost for third party pattern translation tools
• Eliminated delay associated with pattern translation
• Reduced development costs allocated to debugging errors in test patterns on the tester
• Improved yield through vastly improved failure diagnosis capabilities

Company Background
Inovys was founded by Clyde Armstrong, Phil Burlison, Ric Dokken and Tommie Berry in 1999. Our strategy is to proliferate the adoption of standard over proprietary tester languages, promote testability methodologies at every stage, and dramatically improve the profitability of new semiconductor products to their manufacturers by addressing the total cost of testing. Since then, we have delivered our first product to market and are aggressively developing advanced hardware and software solutions to the economic crisis in profitability due to semiconductor test.

Description of Integration
The process of using the integration features between Inovys Stylus and Mentor Graphics' FastScan involve:

1. Producing STIL formatted test patterns by using FastScan and Mentor Graphics' ASIC Vector Interface.
2. Loading these patterns into Stylus along with a test program and driving the target device.
3. Collecting complete failure data for the target device and reporting it in FastScan defect diagnosis format.
4. Loading the design description, patterns, and failure data into FastScan and using the diagnosis function.

The process of validating test patterns without the device or tester by using Inovys Stylus with ModelSim involve:

1. Making ModelSim aware of the Inovys PLI module through ModelSim's configuration files
2. Instantiating and connecting the tester interface and the target device design in a top level Verilog module.
3. Initiating ModelSim simulation in lieu of a tester and a physical device.
4. Loading the patterns to be validated into Stylus and connecting to ModelSim.
5. Executing the patterns in Stylus and reviewing error messages to discover incompatibilities.

Platforms Supported

Distribution and Contact Information