COMMUNICATION CIRCUIT MONITORING DEVICE

摘要

PROBLEM TO BE SOLVED: To acquire a protocol data unit frame in an on-line monitor recording mode without deteriorating the on-line recording transfer efficiency by assembling the physical layer cell extracted from a communication circuit into a unit that is adaptive to the form of a host layer and recording this unit to plural storage means. SOLUTION: This device monitors a communication circuit which performs the communication via a protocol architecture including a physical layer and a host layer having a higher rank than the physical layer. A cell extraction circuit 10 extracts the cell and the clock of the physical layer from the communication circuit to be monitored. A PDU(protocol data unit) frame assembling circuit 12 assembles the extracted cell into a unit that is adaptive to the data form of the host layer with a primary buffer memory 14 used as a work memory. Then the assembled unit is recorded to a secondary buffer memory 16 and also a unit used for the on-line reference is recorded to a tertiary buffer memory for the on-line recording of the assembled unit.