Abstract: A system on a circuit board includes a plurality of devices designed to access an electronic system on the circuit board, and a programmable logic device (PLD) connected to the plurality of devices. Each of the plurality of devices complies with a test port architecture. The PLD interfaces the plurality of devices with a test port. The PLD is capable of configuring different connectivity among the plurality of devices based on the program implemented and the assertion of input control signals. A method and apparatus configures a plurality of devices on a circuit board into a desired configuration using the PLD. The configuration includes (a) receiving a control signal at the PLD, (b) configuring at least one of the plurality of devices into a chain based on the control signal, and (c) coupling the configured chain to the test port via the PLD.

Abstract: A method for testing a transmission system is disclosed. The method comprises receiving a time division multiplexed (TDM) stream on an input of the transmission system. The method also comprises inserting test data in one or more of the plurality unused fields of the TDM stream. Additionally, the method comprises transferring the TDM stream along a plurality of components of the transmission system and comparing the test data against the transferred test data.

Abstract: An integrated circuit is provided for a trunk interface which can test a trunk interface card. Switching circuitry couples tip and ring leads to signal detection circuitry which detects the typical ring and lead signal information. During testing, a test signal is generated which causes the detection circuitry to be coupled to sets of simulated ring and tip test signals which can test the functionality of the integrated circuit and the signal detection circuitry.