In-circuit-emulation tools are being prepared to debug 16 and 32-bit microprocessor and microprocessor-based-system software and hardware. One emulator features totally transparent operation implemented through a dual-bus structure for real-time control and monitoring. During emulation, software and hardware analyses are controlled through trace, counter, snapshot-memory, histogram, and time and event displays. It runs continually, eliminating user-refresh and direct-memory-access problems. Support for the system is implemented through a 24-bit address bus and a 16-bit data bus. Both are expandable to 32 bits to support coming processors.