Fast window test method of hysteresis test

The conventional method of hysteresis test for digital input pin, as defined by (Vih-Vil), performs two VLS (Voltage Level Search) to measure the actual Vih and Vil. A typical tester spends an average of 120 ms for each VLS, resulting in a test time of 240 ms for each pin requiring a hysteresis test. This paper introduces a new method which is 70 times faster than the conventional method. The presented test algorithm is in pseudo-code format for easy translation to PASCAL, C, FORTRAN, or other language.