Method and apparatus for increasing the effectiveness of system debug and analysis

摘要

A trace array for recording states of signals includes N-storage locations for k trace signals. In the write mode, an address generator combines the outputs of an event signal counter and a cycle clock counter to generate trace array addresses. A start code is written each time an event signal occurs and event addresses are saved. Recording is stopped by a stop signal and the stop address is saved. A compression code and time stamp code are written when no state changes occur in any trace signals at the cycle clock times to compress recorded trace signal data. An output processor reads out stored states of the trace signals and uses the start codes, event addresses, stop address, compression code and time stamp to reconstruct the original trace signal sequences for analysis.