A method and processor for debugging a target processor. The method comprises: executing code on the target processor to generate trace information for debugging; and during execution of that code, periodically incrementing a value of a counter on the target processor. The execution of the code includes executing a plurality of timestamp instructions on the target processor each to associate a respective timestamp with the trace information. The execution of each timestamp instruction comprises generating the respective timestamp by reading the value of the counter into a software accessible storage location and subsequently resetting the counter.