Testability architecture and techniques for programmable interconnect architecture

In a suer-configurable integrated circuit including a plurality of conductors which may be connected to one another, to functional circuit blocks having first connection nodes for inputs and outputs thereto, and to input/output circuit blocks having second connection modes for inputs and outputs thereto, by programming user-programmable elements to form electronic circuits, at least one of said conductors comprising one of said first and second connection nodes, apparatus for testing for connectivity defects in the form of ohmic connections between different ones of said conductors prior to formation of said electronic circuits by a user, including:

• means, responsive to signals provided to said integrated circuit from an external source, for temporarily connecting together a first group of said conductors to form a first circuit node during a first time period;
• means, responsive to signals provided to said integrated circuit from an external source, for temporarily connecting together a second group of said conductors to form a second circuit node during said first time period;
• means for placing an electrical charge onto said first circuit node during a second time period within said first time period such that a selected dynamic voltage is placed on said first circuit node;
• means for driving said second circuit node to a voltage different from said selected dynamic voltage during a third time period subsequent to said second time period and within said first time period;
• means for sensing the voltage on said first circuit node at a predetermined time after the start of said third time period and within said first time period;
• means for storing a signal related to the voltage on said first circuit node at said predetermined time after the start of said third time period;
• and
• means for communicating said signal to an input/output pad of said integrated circuit.

In a user-configurable integrated circuit including a plurality of conductors which may be connected to one another, to functional circuit blocks having first connection modes for inputs and outputs thereto, and to input/output circuit blocks having second connection nodes for inputs and outputs thereto, by programming user-programmable elements to form electronic circuits, at least one of said conductors comprising one of said first and second connection nodes, apparatus for testing for connectivity defects in the form of charge leakage paths from selected ones of said conductors prior to formation of said electronic circuits by a user, including:

• means, responsive to signals provided to said integrated circuit from an external source, for temporarily connecting together said selected ones of said conductors during a first time period to form a node;
• means for placing an electrical charge onto said node during a second time period within said first time period such that a selected dynamic voltage is placed on said node;
• means for sensing the voltage on said node at a predetermined time after the start of said third time period and within said first time period;
• means for storing a signal related to the voltage on said node at said predetermined time after the start of said third time period;
• and
• means for communicating said signal to an input/output pad of said integrated circuit.