Patent ID: 6781958
Filing Date: 2004-08-24
Classification: H04J

Abstract:
A monitor circuit for extracting administration information in a communication frame including a plurality of administration information and a plurality of communication data, the monitor circuit comprising:a storage circuit including: (a) a high-speed storage circuit temporarily storing one of the plurality of administration information inputted through the change-over switch at high speed; and (b) a low-speed storage circuit receiving the one of the plurality of administration information from the high-speed storage circuit through the change-over switch, the low-speed storage circuit storing all of the plurality of administration information at low speed, and a change-over switch to receive the communication frame, the change-over switch operable to output the administration information in the communication frame to the storage circuit in accordance with a predetermined input signal only when administration information is received, wherein the change-over switch is changed over to output the one of the plurality of administration information to the high-speed storage circuit when the change-over switch receives the one of the plurality of administration information in the communication frame, wherein the change-over switch is changed over to output the one of the administration information stored in the high-speed storage circuit to the low-speed storage circuit when the change-over switch receives one of the plurality of communication data in the communication frame, and wherein all of the plurality of administration information in the communication frame are stored and extracted in the low-speed storage circuit.