Serial test patterns for mosfet testing

Abstract

Abstract A technique of decreasing the number of test patterns required to test a MOSFET module and/or provide the ability to test elements on the module which can not be tested by conventional test techniques. Conventionally, test patterns are applied to the input pins of a MOSFET module and the output monitored at the output pins of the module. Interwoven with the normal test pattern testing is the application of a serial test pattern to selected elements on the module. The serial test pattern is applied to a single input pin on the module and a serial test pattern is stored in a shift register which is on the module. Each of the stages of the shift register are used to control or monitor an element or point which may be otherwise inaccessible or untestable and the shift register is also utilized in an output mode to provide an indication serially on a single output pin as to the functioning of the points accessed on the module. The sequence then is to input onto a single input pin a serial test pattern for testing, controlling or monitoring various elements or nets on the module; reload the shift register in accordance with the test results; and then serially shift the contents of the shift register out onto the single output pin while monitoring this output to determine whether the elements or nets are functioning properly. In addition, while the serial test pattern is applied the output appearing at the output pins of the module may be monitored.

Inventors

• 👤 R James

Bibliographic Details