Patent ID: 9316684
Filing Date: 2016-04-19
CPC Classification: G01R

Claim Text:
1. A semiconductor device for detecting degradation which occurs in a semiconductor integrated circuit having a detection target circuit portion where a test is executed, comprising: a decision unit that judges whether the test is executed within an allowable test timing in the detection target circuit portion at each test operation frequency or not and decides a maximum test operation frequency at which the test can be executed; a measurement unit that measures variables indicating test environment, the variables being a temperature and a voltage of where the detection target circuit portion is; and a calculation unit that converts the maximum test operation frequency decided by the decision unit based on the temperature and the voltage measured by the measurement unit into a maximum test operation frequency at a standard temperature and a standard voltage, and calculates, based on a converted maximum test operation frequency, a degradation amount which indicates degree of degradation; wherein the semiconductor integrated circuit has a monitor block circuit that monitors a value used by the measurement unit to measure the temperature and the voltage; the measurement unit has an estimation unit that estimates a temperature and a voltage of where the detection target circuit portion is, every time a test is executed, based on a monitored value by the monitor block circuit which operated at a temperature and a voltage of where the detection target circuit portion is; the calculation unit uses the temperature and the voltage estimated by the estimation unit as the temperature and the voltage measured by the measurement unit and converts the maximum test operation frequency decided by the decision unit into the maximum test operation frequency at the standard temperature and the standard voltage; the semiconductor device further comprises n (n is an integer equal to or more than 2) of the monitor block circuits; the measurement unit measures a measured frequency F the estimation unit estimates the temperature T and the voltage V of where the detection target circuit portion is by calculating coefficients α