BUS TRACE DEVICE AND METHOD

摘要

PURPOSE: To provide a bus trace device of high performance which can eliminate the discontinuation of the system operation in a fault detection mode and the change of the circuit constitution that is required in response to the fault detection mode by using a bus trace function that is connected to the system and adaptive to the different fault detection modes. CONSTITUTION: A bus trace device is connected to a system bus 2 and traces the bus information necessary for detection of faults. Then the bus trace device is provided with a trace memory 13 of large capacity consisting of a DRAM of a double memory block system and a fast trace memory 14 which serve as the trace memories that store the trace data. A bus trace control circuit 15 controls the trace operations and also controls the write operations of both memories 13 and 14 in accordance with the trace start/stop conditions that are set by an SVP 4.