Application Initiated Tracing of Its Operation Beginning With Reset

摘要

This invention includes a state machine entering a first state upon cold reset of the data processing system. Trace information collection and trace information export are prohibited in the first state. The state machine transits from said first state to a second state upon a change in a predetermined bit to a first state. Direct memory access setup is enabled in the second state. The state machine transits from the second state to a third state upon set up of the direct memory access. Trace information collection is enabled in the third state. The state machine transits from the third state to a fourth state upon a direct memory access request corresponding to the direct memory access setup in the second state. Trace data export via direct memory access from the trace collection unit is enabled in the fourth state.