Methods and structure for utilizing external interfaces used during normal operation of a circuit to output test signals

Abstract

Methods and structure are provided for routing internal operational signals of a circuit for output via an external interface. The structure includes an integrated circuit. The integrated circuit comprises a block of circuitry components operable to generate internal operational signals for performing designated functions during normal operation of the circuit, a control unit, a test signal routing hierarchy, and an external interface. The test signal routing hierarchy is coupled to receive the internal operational signals and controllably selects the internal operational signals for acquisition and applies them to the control unit. The external interface provides communications between the integrated circuit and an external device during normal operation of the integrated circuit. The control unit receives the selected internal operational signals from the test signal routing hierarchy, and applies the selected internal operational signals to the external interface during normal operation of the integrated circuit.

Dependencies are inferred from the claim text.