US Patent 9158720 System and method for scalable trace unit timestamping

An integrated circuit includes a trace subsystem that provides timestamps for events occurring in a trace source that does not natively support time stamping trace data. A timestamp inserter is coupled to such a trace source. The timestamp inserter generates a modified trace data stream by arranging a reference or references with the trace information from the trace source on a trace bus. A trace destination receives the modified trace data stream including the reference(s). In some embodiments, a timestamp inserter receives a timestamp request and stores a reference in a buffer. Upon later receipt of trace information associated with the request, the timestamp inserter inserts the reference, a current reference and the received trace information into the trace data stream.