On-the-fly improvement of certainty of statistical estimates in statistical design, with corresponding visual feedback
View Patent ↗A system and method to analyze analog, mixed-signal, and custom digital circuits. The system and method displays to a user characteristic values of a circuit and statistical uncertainty values of the characteristic values early in a sampling or characterization run of the circuit. The characteristic values and their statistical uncertainties are updated as the sampling or characterization run progresses. The user can halt the sampling or characterization run once a desired level of uncertainty is attained. The system can automatically halt the sampling or characterization run, once the statistical uncertainty lie within a pre-determined range.
1. A non-transitory, tangible computer-readable medium containing instructions, which when executed by a processor cause the processor to perform a method to analyze an electrical circuit design (ECD), the method comprising steps of:
a) obtaining simulation data for multiple candidate designs of the ECD, the ECD having associated therewith at least one of circuit variables and circuit performance metrics;
b) processing the simulation data in accordance with pre-determined rules to obtain characteristic data of the ECD and to determine a characteristic value of the ECD, the characteristic value of the ECD depending on the at least one of circuit variables and circuit performance metrics;
c) processing the characteristic data of ECD to determine a statistical uncertainty of the characteristic value;
d) determining if the statistical uncertainty of the characteristic value is outside a pre-determined range;
e) only if the statistical uncertainty of the characteristic value is outside the pre-determined range, obtaining further simulation data for further candidate designs of the ECD to add to the simulation data and repeating steps (b) through (d); and,
f) while steps (a) through (e) are performed, and when the characteristic value and the statistical uncertainty of the characteristic value have been determined, providing runtime feedback by displaying, for assessment of the ECD, the characteristic value and the statistical uncertainty of the characteristic value,
displaying the characteristic value and the statistical uncertainty of the characteristic value including at least one of:
plotting the characteristic value and a confidence interval of the characteristic value;
plotting the characteristic value and a confidence interval of the characteristic value as a function of runtime;
plotting the characteristic value and a statistical p-value of the characteristic value; and
plotting a relative impact and a confidence interval of the relative impact of some of the circuit variables on a yield of the ECD.
2. The non-transitory, tangible computer-readable medium of claim 1 wherein:
obtaining simulation data for multiple candidate designs of the ECD includes simulating multiple candidate designs of the ECD; and
obtaining further simulation data of multiple candidate designs of the ECD includes further simulating multiple candidate designs of the ECD.
3. The non-transitory, tangible computer-readable medium of claim 1 wherein:
obtaining simulation data for multiple candidate designs the ECD includes accessing a database containing the simulation data to extract the simulation data from the database; and
obtaining further simulation data for multiple candidate designs of the ECD includes further accessing the database containing the simulation data to further extract simulation data from the database.
4. The non-transitory, tangible computer-readable medium of claim 1 wherein the circuit variables include at least one of design variables of the ECD, environmental variables of the ECD and process variables of the ECD.
5. The non-transitory, tangible computer-readable medium of claim 1 wherein the circuit performance metrics include at least a manufacturing yield of the ECD.
6. The non-transitory, tangible computer-readable medium of claim 2 wherein the step of simulating the ECD includes performing a SPICE simulation of the ECD to obtain SPICE-data and the step of processing the characteristic data of the ECD includes at least one of performing a sampling run of the SPICE-data and performing a characterization run of the SPICE-data.
7. The non-transitory, tangible computer-readable medium of claim 1 wherein the pre-determined rules include a pre-determined data-mining algorithm.
8. The non-transitory, tangible computer-readable medium of claim 1 wherein the pre-determined rules include a pre-determined model-building algorithm.
9. The non-transitory, tangible computer-readable medium of claim 1 wherein the pre-determined rules include a pre-determined statistical algorithm.