Patent ID: 8055950

Claim:
A data processing apparatus having one or more trace data sources, said trace data sources operating to generate respective streams of trace data, at least one of said trace data sources comprising: a trace data generator responsive to activity in monitored circuitry to generate trace data representing said activity; a synchronization marker generator coupled to said trace data generator, said synchronization marker generator, responsive to a synchronization request, to generate a synchronization marker and insert said synchronization marker into said trace data stream, said synchronization marker identifying a synchronization position in said trace data stream; and a controller coupled to said synchronization marker generator, said controller operating to initiate said synchronization marker generator to generate and insert said synchronization marker into said trace data stream; wherein said controller controls the timing of initiation following the synchronization request in dependence on behaviour of said data processing apparatus downstream of said trace data generator with respect to trace data flow to delay the insertion of a synchronization marker into the trace data stream until sufficient bandwidth is determined to be available downstream.