| 摘要 |
An apparatus and method for processing data is disclosed. The apparatus comprises a data processing circuit operable over a sequence of processing cycles to perform data processing operations in response to program instructions and a tracing circuit configurable to perform a selected one of a number of tracing activities in which corresponding trace data is generated indicative of operation of the data processing circuit in response to the program instructions. The tracing circuit is operable to be responsive to trace instructions inserted into the program instructions to control execution of the selected one of a number of tracing activities in order to generate the trace data, each trace instruction being operable to control execution of each of a number of the tracing activities. Hence, the tracing circuit is operable to perform a number of tracing activities and is configurable to perform a selected one of those tracing activities. Trace instructions are inserted into the program instructions of the software code to be analysed. The occurrence of the trace instructions in the program instructions controls the execution of the selected tracing activity. Hence, each occurrence of a trace instruction can control the tracing activity. By controlling the execution of the tracing activity using trace instructions rather than by using trigger logic, the number of conditions under which trace data is generated can be greatly increased. Because each tracing instruction controls a number of tracing activities the number of different tracing instructions required to be provided can be limited. Hence, it will be appreciated that the effect of any particular trace instruction will vary depending on the configuration of the tracing circuit and the tracing activity which has been selected. Accordingly, the same trace instruction can have a different effect depending on the arrangement of the trace circuit. Such an arrangement enables a wide range of tracing activities to be performed and a variety of trace data to be generated whilst still being controlled by a small number of trace instructions.
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