Microcomputer executing compressed program and generating compressed branch addresses

摘要

An executable program is stored in compressed form in a ROM, from which compressed program data is fetched to be expanded by an expandor to a pre-compression form. The expanded data is then decoded by an instruction decoder for execution. This novel setup reduces a memory usage amount in main storage including the ROM. If a branch instruction appears, a controller converts a pre-compression branch destination address to a corresponding post-compression branch destination address and sets a value thereof to a program counter.