A method, apparatus and computer program product are provided for implementing atomic data tracing in a processor system including an auxiliary processor unit (APU) coupled to a central processor unit (CPU). The auxiliary processor unit (APU) processes a trace instruction. When a trace instruction is identified by the APU, the APU signals the CPU with a pipeline stall signal for stalling the CPU and checks for an enabled trace engine as specified by the trace instruction. When the trace engine for the trace instruction is enabled, then the trace data is written into a trace buffer. The APU signals the CPU with an op done signal for allowing the CPU to continue with instruction processing.