Method for Testing Paths to Pull-Up and Pull-Down of Input/Output Pads

摘要

A SCAN chain architecture for each path in a circuit having combinational paths includes a control mechanism to control one or more flip flops and multiplexers to direct operational or test signals. Operational signals are sent along at least one combinational path to a pull-up/pull-down for at least one input/output pad and an operational voltage is recorded. Test signals are sent along at least one alternative path to an alternative input/output and a test voltage is recorded. The operational voltage is compared to the test voltage to identify a combinational path fault.

主权项

1. A circuit, comprising:
a test control logic having at least one input and at least one output; a first flip flop; a first multiplexer; and a first three-state gate, wherein:
an output from the first flip flop is configured as an input to the first multiplexer;a first output of the at least one outputs of the test control logic is configured as an input to the first multiplexer; andthe output of the first multiplexer is a combinational path to a pull-up/pull-down of an input/output pad.