Abstract: Diagnostic operations upon a target apparatus 2 having a target transaction master 8 which initiates memory transactions with one or more target transaction slaves 12, 14, 16 are provided by halting operation of the target transaction master 8 while permitting continued operation within the target apparatus 2 of at least some of the target transaction slaves 12, 14, 16. Opening state data representing an operating state of the target transaction master 8 is transferred to a model transaction master 32. Further operation of the target transaction master 8 is emulated using the model transaction master 32 using the opening state data. Diagnostic operations are performed upon the model transaction master 32. When the model transaction master 32 emulates initiation of a memory transaction with a memory address mapped to one of the target transaction slaves 12, 14, 16, this initiates the memory transaction to be performed with the target apparatus 2.

Abstract: A trace data capture device has trace storage circuitry for storing trace data captured from a data processing apparatus. Detection circuitry detects source identifiers identifying which trace source generated the trace data. Output circuitry outputs to a diagnostic apparatus, independently from the trace data, source identifying data which indicates which source identifiers were detected for the trace data stored in at least a portion of the trace storage circuitry. By allowing the diagnostic apparatus to determine which source identifiers have been detected for which region of the memory, this can allow more targeted uploads of trace data, to reduce the time required for uploading the trace data and reduce the time to determine if data is not present for a particular source.

Abstract: Diagnostic operations upon a target apparatus 2 having a target transaction master 8 which initiates memory transactions with one or more target transaction slaves 12, 14, 16 are provided by halting operation of the target transaction master 8 while permitting continued operation within the target apparatus 2 of at least some of the target transaction slaves 12, 14, 16. Opening state data representing an operating state of the target transaction master 8 is transferred to a model transaction master 32. Further operation of the target transaction master 8 is emulated using the model transaction master 32 using the opening state data. Diagnostic operations are performed upon the model transaction master 32. When the model transaction master 32 emulates initiation of a memory transaction with a memory address mapped to one of the target transaction slaves 12, 14, 16, this initiates the memory transaction to be performed with the target apparatus 2.

Abstract: A trace data capture device has trace storage circuitry for storing trace data captured from a data processing apparatus. Detection circuitry detects source identifiers identifying which trace source generated the trace data. Output circuitry outputs to a diagnostic apparatus, independently from the trace data, source identifying data which indicates which source identifiers were detected for the trace data stored in at least a portion of the trace storage circuitry. By allowing the diagnostic apparatus to determine which source identifiers have been detected for which region of the memory, this can allow more targeted uploads of trace data, to reduce the time required for uploading the trace data and reduce the time to determine if data is not present for a particular source.