Synthesizing the instruction stream executed by a microprocessor from its branch trace data

摘要

A system for capturing the data necessary for synthesizing an instruction stream for a microprocessor. An embodiment uses a microprocessor that is adapted to write its branch trace data to the main memory. This branch trace data includes whether the microprocessor took each conditional jump encountered during the execution of a program as well as the target location of each indirect jump. The preferred embodiment further includes a logic analyzer coupled to the primary expansion bus of the target computer system. The logic analyzer captures input/output reads and writes as well as DMA transactions to the main memory. Finally, a synthesis control card controls starting a data capture as well as facilitating the transfer of information from buffers in the main memory to the control computer system. Using this information, a user may reconstruct the instruction steam as actually executed during a particular run of a program which may aide the user in performance analysis and design improvements for microprocessors.