Method, system, and computer program product embodiments of a time-based trace facility for facilitating software debugging without interfering with the run-time behavior, performance or resource usage of the traced software are provided. The trace facility resides in a different address space than the target address space and uses different time-slices of CPU resources to execute the instructions in the address spaces. The trace facility uses a cross-memory mode to read the state data from the target address space in accordance with a time schedule. The trace facility writes the state data to a trace area, which may be located in either the target or trace address spaces or external storage. With this approach, the trace facility can read a large amount of state data frequently to construct the type of historical record needed to analysis run-time behavior, performance and resource usage.