Alec Stanculescu, Fintronic USA Alex Zamfirescu, ASC MAPLD 2004 September 8-10, 2004...
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Transcript of Alec Stanculescu, Fintronic USA Alex Zamfirescu, ASC MAPLD 2004 September 8-10, 2004...
Alec Stanculescu, Fintronic USAAlex Zamfirescu, ASC
MAPLD 2004September 8-10, 2004
[email protected] [email protected]
Design Verification Method forRadiation Hardness using
Simulation Farms
Fintronic USA
Stanculescu 2 2004 MAPLD/104
Summary
• Problem Addressed• Solution Proposed• Conclusion• Proposed Plan
Fintronic USA
Fintronic USA
Stanculescu 3 2004 MAPLD/104
Introduction
• Circuits malfunction due to radiations– Transient errors may lead to Soft
errors if an erroneous data is latched– Cumulative effects may lead to
permanent ( hard) errors (total dose)
Fintronic USA
Stanculescu 4 2004 MAPLD/104
Problem Addressed
• Reduce the cost of assessing the behavior of very large circuits under different radiation conditions by providing fast feedback to circuit designers regarding:– statistics of faults – reliability – nature of degradation
Fintronic USA
Stanculescu 5 2004 MAPLD/104
Solution Proposed
• Simulate radiation effect by injecting faults in the simulation based on the radiation failure susceptibility of the library cells used
• Use efficiently a simulation farm• Automate the analysis of results
Fintronic USA
Stanculescu 6 2004 MAPLD/104
Radiation Hardness Analyzer
Fintronic USA
Stanculescu 7 2004 MAPLD/104
Radiation Failure Susceptibility
• For each cell, for each wire, record– <time window> <fault_info_triplet>+
• <fault_info_triplet> ::= <p of a given fault-type occurring in the
given window>, <type of fault>, <p of at most one fault of the given
type occurring in the given window>;where p stands for probability
Fintronic USA
Stanculescu 8 2004 MAPLD/104
Creation of Radiation Failure Susceptibility Data
• Calibration of Simulation– High correlation between simulation
results and manufactured circuit
• Calibration Methods– Test all cells at various radiation
environments
Fintronic USA
Stanculescu 9 2004 MAPLD/104
Calibration Methods
• Fabricate all supported cells on tested chip – selection of tests may affect calibration
• Use existing circuits for testing• Use an un-hardened version of the
actual circuit• Use transistor susceptibility based
on specific measurements
Fintronic USA
Stanculescu 10 2004 MAPLD/104
FinFarm:Verilog Simulation Farm
• Enables one engineer to manage many simultaneous simulations – Network of computers– Farming methodology – Farming tools
• Current farms use between 10 and more than 1000 licenses
Fintronic USA
Stanculescu 11 2004 MAPLD/104
Farming Methodology
• Un-partitioned circuits • small footprint & 64-bit simulation helps
• Split stimulus• Simultaneous verification of
alternative components• Program feedback-based
verification
Fintronic USA
Stanculescu 12 2004 MAPLD/104
Farming Tools• Perform automated
– simulation launching – simulation queuing– collection & reporting of simulation
results– collection & merging of code
coverage results• Perform real-time monitoring• Perform programmed re-launching
of simulations
Fintronic USA
Stanculescu 13 2004 MAPLD/104
FinFarm™ Usage
• Regression Testing• Extensive Exploration of Design
Space• Evaluation of Reusable IPs• Analysis of Design Trade-Offs: Power,
Size, Speed and search for optimal solution using feedback loop
• Radiation Hardening
Fintronic USA
Stanculescu 14 2004 MAPLD/104
Rad. Hard. Simulation
• Describing effects on circuit by a given radiation environment, using VCD-F format (VCD fault format)
• VCD-F Reader injects corresponding faults in simulation
• Launching simultaneous simulations using simulation farm
• Collecting and processing results
Fintronic USA
Stanculescu 15 2004 MAPLD/104
VCD-F Format
• VCD IEEE std 1364 results• VCD-F specifies random faults, i.e.
values are replaced by:– Fault types– Randomization info
Fintronic USA
Stanculescu 16 2004 MAPLD/104
VCD-F Reader
• VCD-F Reader injects faults in simulation.
• Nature of faults: permanent, transient
• Kind of faults: stuck at, bridging, cross talk, gate rupture, value toggle, timing, etc.
Fintronic USA
Stanculescu 17 2004 MAPLD/104
Simulation Launching
• Save simulations at various check points, just before inserting faults
• Re-start simulation at latest checkpoint before the injected fault which caused errors
• Launch simultaneous simulations on FinFarm™
Fintronic USA
Stanculescu 18 2004 MAPLD/104
Collecting and Processing Results
• Record results databases• Compare Results Databases• Isolate circuits containing at least
one error, for detailed analysis• List of possible fault type• Produce reports
Fintronic USA
Stanculescu 19 2004 MAPLD/104
Summary of Solution
• Cells are measured once and results are stored in IEEE standard
• Use Monte Carlo technique to establish radiation susceptibility of complex ICs using simulation
• Fast feedback to designers• Major cost reduction
Fintronic USA
Stanculescu 20 2004 MAPLD/104
Proposed Plan
• Establish a radiation assessment lab
• Create oversight task force – Government– Industry – Academia
• Create standards for describing– Radiation failure susceptibility of cells– Distribution of faults in circuits in time