| 摘要 |
PURPOSE:To eliminate requirement of special time for switching of memory, by making a selected program instruction arbitrarily out of the program instructions of memory access exclusively used one of hidden memory access. CONSTITUTION:An operation code coincidence detection circuit 6 interprets the operation code detected from a memory 4. When a selected access is detected out of program instructions of memory access, a memory change signal HCHG is outputted from the circuit 6, to switch a data bus switching circuit 7 to the hidden memory 2. Thus, even after the memory is switched, the switched memory is accessed in the normal instruction reading and execution cycle and no special time is required for the access. Since this switching is independently of the program progress, the address designation of the switched memory is done, allowing to attain memory usage efficiently. |
