Patent ID: 7571413
Filing Date: 2009-08-04
Classification: G01R,H03K

Abstract:
1. A method of testing programmable power supply voltage selection switches on a programmable integrated circuit having a plurality of test circuits, each test circuit being associated with a respective one of the programmable power supply voltage selection switches, comprising: loading a test pattern of configuration data into the programmable integrated circuit that is used in adjusting the programmable power supply voltage selection switches to produce selected voltages at their outputs; and using the test circuits to measure the selected voltages to produce test results, wherein the programmable integrated circuit contains a plurality of power supply voltage distribution lines each having a different associated power supply voltage, each programmable power supply voltage selection switch having inputs connected respectively to the plurality of power supply voltage distribution lines and having an output, wherein each test circuit has a first input connected to one of the plurality of power supply voltage distribution lines and a second input connected to the output of its associated programmable power supply voltage selection switch, and wherein using the test circuits comprises producing the test results by using the test circuits to compare voltages on the first and second inputs.