Systems and methods for analyzing transactions on a bus. A software module can cause a trace packet to be generated and sent out on a bus to an invalid address. The trace packet triggers a protocol analyzer and permits the bus data flowing on the bus when the software module detected a problem to be analyzed. The trace packet causes the protocol analyzer to trigger even though the bus protocol is normal and the protocol analyzer would not otherwise trigger. The trace packet can be used to analyze and debug communications flowing on a bus when the software module detects a problem.