Network Interfacing Unit (NIU) Test Circuit

摘要

end. FIELD OF THE INVENTION The present invention relates to circuitry for independently testing a network interfacing unit.;I. The technical problem to be solved by the present invention is to provide a network interfacing unit test circuit capable of independently testing and maintenance in the ATM set-top box irrespective of the signal received from the remaining functional block circuit unit other than the network interfacing unit unit. .;All. Summary of the Invention Solution of the Invention: A network interfacing unit connected to a physical communication transmission medium such as a telephone line for modulating and transmitting ultra-high speed data, and a circuit unit for converting the data received from the network interfacing unit to be displayed on a display device. In the asynchronous transmission mode set-top box having a signal, the signal blocking / passing circuit for blocking or passing the signal transmitted from the circuit portion to the network interfacing unit according to the open or short state of the jumper, and the jumper of the signal blocking / passing circuit And a gate circuit unit for generating and outputting signals for independently initializing the network interfacing unit while all signals transmitted to the network interfacing unit are blocked by the operation.;la. Significant Uses of the Invention: Can be used for ATM set-top boxes or standalone network interfacing units.