Patent ID: 7080289

Claim:
Apparatus for processing data, said apparatus comprising: (i) a register bank having a plurality of registers and operable to store data words to be processed: (ii) processing logic operable in response to a multi-word data transfer instruction to transfer a plurality of data words between respective registers within said register bank and respective storage locations within a data memory; and (iii) tracing logic triggered by detection of a predetermined trace initiating condition to commence tracing operation generating a trace data stream of trace data part way through said multi-word data transfer instruction whereby a subset of transfers of said plurality of data words are traced within said trace data stream, wherein all transfers of said multi-word data transfer instruction subsequent to said detection of said predetermined trace initiating condition are traced within said trace data stream, wherein said predetermined trace initiating condition is triggered from a triggering transfer with subsequent transfers giving rise to trace data even though they do not meet said predetermined trace initiating condition, wherein said triggering transfer gives rise to transfer trace data within said trace data stream and said subsequent transfers give rise to place holder trace data within said trace data stream, said place holder trace data being more compact and giving less information regarding a transfer than said transfer trace data.