Abstract: An in-circuit emulator (ICE) for hardware/software development and debugging microprocessors. Program execution reconstruction is extracted from an on-board cache memory. An external ICE enclosure interfaces to a target system microprocessor via a cable and a buffer/interface pod. A control program directs a non-intrusive emulation and a monitor program resides in a personal computer host and supports ICE commands. The monitor program allows a user to follow a target system's program flow, to capture related processor information, to make program modifications, and allows the user to restart programs. An on-line disassembler presents a display so as to allow the designer to examine memory, using instruction mnemonics rather than hexadecimal values, thus improving the designer's ability to read program memory. A bit trace buffer records the state of each the microprocessor's signals during each cycle of each instruction.