Abstract: An integrated circuit is provided with latency detecting circuitry for detecting signal generation latency within one or more functional circuits and in response thereto to generate a wearout response. The wearout response can take a variety of different forms such as reducing the operating frequency, increasing the operating voltage, operating task allocation within a multiprocessor system, manufacturing test binning and other wearout responses.

Abstract: A trace data formatter 30 assembles trace data frames 50. These trace data frames 50 include bytes which may either serve to carry a trace data source identifier ID or trace data. A system being traced has multiple trace data sources 12, 14, 16, 18 and when the trace data source which is generating the current trace data stream changes then a trace data source identifier ID is inserted within the trace data stream.

Abstract: A trace data system is provided in which flush request signals are generated and passed to trace data sources to trigger them to output any buffered trace data they are storing which was generated prior to the flush request being signalled. When the trace data has been flushed from these trace data sources, they signal this by generating a flush complete signal. The flushing of trace data may advantageously be performed prior to a power-down operation and using a trace bus bridge.

Abstract: Within an integrated circuit 2 independently controllable domains 4, 6, 8, 10, 12, 14 may be unable to complete pending transactions taking place between domains. Each domain is provided with a transaction level state machine 20, 22 which is responsive to the state of the state machine within the other domain and when this indicates that the other domain is not capable of communicating triggers default behavior ensuring that the predetermined transaction protocol is not broken.

Abstract: An integrated circuit 2 is provided with multiple sources 12, 14, 16, 18 of trace data streams that are input via respective dedicated trace buses 20, 24 to a trace data stream combiner 22, 26. The trace data bus has trace data signal lines ATDATA for carrying trace data signals and trace source identifying signal lines ATID for carrying trace source identifying signals. A trace data stream replicator 28 may be used to replicate a single trace data stream such that the resulting multiple trace data streams may be subject to different post-replication processing/filtering as desired.

Abstract: An integrated circuit is provided with multiple data processing components associated with respective sources which generate trace data streams. A reference timestamp generator is provided and the trace data streams are annotated such that they are output off-chip together with reference timestamp data. Outputting the reference timestamp data together with the trace data streams enables temporal correlation between points in different trace data streams by trace analysis tools.