Method and apparatus for monitoring automated testing of electronic circuits
First Claim
1. A method for continuously applying and monitoring a test bias signal at a node of a device under test including digitally programmed source means having a preselected programmed voltage-current characteristic defined by not-to-exceed voltage rail and current rail levels for supplying a test bias signal to the node, comparison means connected to the node, and means for latching the output signal produced by the comparison means, the method comprising the steps of:
- connecting the test bias signal to the node;
continuously comparing the voltage applied to the node with the preselected programmed voltage rail level;
providing an indication of the relative magnitude of the voltage applied to the node with respect to the voltage rail level;
setting first latching means when the voltage applied to the node reaches the voltage rail level;
continuously comparing the current at the node with the preselected programmed current rail level;
providing an indication of the relative magnitude of the current at the node with respect to the current rail level; and
setting second latching means when the current at the node reaches the current rail level.
3 Assignments
0 Petitions
Accused Products
Abstract
A plurality of signal applying and monitoring circuits are coupled to pins of an electronic device being tested to force test stimuli signals representing logic states or other parameters onto input pins of the device under test. The responses to the stimuli signals are monitored while the device is being tested. Each signal applying and monitoring circuit includes a node to be coupled to a pin of the device under test, a device power supply connected to the node for supplying a test bias signal, a comparison circuit connected to the node for indicating the relative magnitude of the test bias signal with respect to the bias level at the node, and a latch circuit responsive to the output signal produced by the comparison circuit. The device power supply is included for providing test bias signals to test power drain during functional testing. The transitions of the device power supply are monitored and latched for providing a record of the power drain of the device being tested. Other features are also disclosed.
143 Citations
12 Claims
-
1. A method for continuously applying and monitoring a test bias signal at a node of a device under test including digitally programmed source means having a preselected programmed voltage-current characteristic defined by not-to-exceed voltage rail and current rail levels for supplying a test bias signal to the node, comparison means connected to the node, and means for latching the output signal produced by the comparison means, the method comprising the steps of:
-
connecting the test bias signal to the node; continuously comparing the voltage applied to the node with the preselected programmed voltage rail level; providing an indication of the relative magnitude of the voltage applied to the node with respect to the voltage rail level; setting first latching means when the voltage applied to the node reaches the voltage rail level; continuously comparing the current at the node with the preselected programmed current rail level; providing an indication of the relative magnitude of the current at the node with respect to the current rail level; and setting second latching means when the current at the node reaches the current rail level. - View Dependent Claims (2, 3, 4, 5)
-
-
6. Apparatus for continuously applying and monitoring a test bias signal to a node of a device under test, comprising:
-
digitally programmed source means connected to the node, the digitally programmed source means having a preselected programmed voltage-current characteristic defined by not-to-exceed voltage rail and current rail levels for supplying test bias signals to the node; first comparison means connected to the node for continuously comparing the voltage applied to the node with the preselected programmed voltage rail level; first latching means for providing an indication when the voltage applied to the node reaches the voltage rail level; second comparison means connected to the node for continuously comparing the current at the node with the preselected programmed current rail level; and second latching means for providing an indication when the current at the node reaches the current rail level. - View Dependent Claims (7, 9, 11)
-
-
8. fifth latching means for providing an indication when the test bias signal voltage applied to the node is negative and the test bias signal current at the node is negative;
- and
sixth latching means for providing an indication when the test bias signal voltage applied to the node is negative and the test bias signal current at the node is positive. - View Dependent Claims (10, 12)
- and
Specification