Testability Analysis - TurboCheck
TurboCheck is a Testability Analyzer and Test Assistant for both RTL (Register-Transfer-Level) and gate-level digital designs. TurboCheck analyzes the testability of sequential circuits and assists the designer in selecting test solutions that are most likely to improve the circuit's final fault coverage. TurboCheck operates on non-scan, partial-scan, or full-scan circuits. Because it is a static tool operating on the topology of the circuit, no vectors are needed for the analysis.
Two Levels of Checking
SynTest offers two versions of TurboCheck: TurboCheck-RTL and TurboCheck-Gate, to support different levels of checking throughout the design cycle. Each of these versions offers its own benefits.
TurboCheck-RTL identifies testability problems at the earliest stage of the design cycle - right after RTL coding. By checking the RTL codes, the designers can check for testability rule violations sooner, even before the often time-consuming logic synthesis process. This reduces design iterations, and helps designers achieve design-for-test goals quicker. With TurboCheck-RTL, up to 80% of the testability problems can be detected at RTL coding before synthesis.
TurboCheck-Gate is used after the design is synthesized into gates. Since the RTL design has been checked by TurboCheck-RTL before synthesis, TurboCheck-Gate can perform a structural-level check once or twice on the final design to further identify and zero-in on the final testability violations that cannot be detected at RTL coding.
Provides Immediate Feedback
TurboCheck provides fast feedback about potential design and testability problems during the design phase of the circuit, allowing changes to be made early in the design process. This flow minimizes the impact of testability considerations on other important constraints of the design.
Since TurboCheck-RTL checks your RTL codes, it does not depend on the type of technology libraries used in the design. Therefore, designers will get immediate benefits from TurboCheck-RTL without having to learn a new design flow.
Computes Controllability and Observability Values
TurboCheck computes controllability and observability values according to the structure of the design. These testability values are used to identify test problems that could possibly affect the fault coverage of the design. In addition to average controllability and observability values for the design, TurboCheck reports the nodes that are either uncontrollable or unobservable. This allows a designer to quickly isolate and review potential problem areas.
Highlights Potential Circuit Testability Issues
Beyond just computing testability values, TurboCheck identifies test problems such as combinational feedback loops, generated clocks, gated clocks, floating buses, and many other logical design guidelines for testable circuit design. These reports direct the designer to the precise location in the design where the problem occurs, enabling quick scan of the design for test issues.
Selects Scan and Test Points
With TurboCheck-Gate as Test Assistant, you select manual or automatic insertion of test points. With automatic scan selection, TurboCheck-Gate will recommend a near-optimal set of test points for test control, test access, or both. When scan selection is done manually, TurboCheck-Gate allows selection of test points using any external scan selection algorithm, and analyzes the effect of the selection on the testability of the circuit. By manually selecting or excluding scan points, timing-critical circuitry can be excluded from the scan chain to minimize the impact of scan on design performance.
Testability Problems Identified
- Floating Nets and Ports
- Combinational Feedback Loops
- Uncontrollable or Unobservable Nodes
- Potential Bus Contention
- Floating Busses
- Combinationally Gated Clocks
- Sequentially Generated/Gated Clocks
- Sequentially Generated/Gated Asynchronous Set/Reset
- Transparent Latches
Supported Input Formats
- TurboCheck-RTL: Synthesizable Verilog RTL
- TurboCheck-Gate: Structural-Level Verilog, VHDL
- Sun Solaris