| 摘要 |
PURPOSE:To perform the prescribed information processing by means of an RAM even in case a microprocessor opens a bus by providing the RAM to which a direct access is possible from the microprocessor. CONSTITUTION:The programs or data to be executed are fetched into a built-in RAM before a microprocessor MPU opens buses AB and DB for execution of a direct memory access. Then the MPU performs the prescribed data processing based on the program fetched to the RAM after the buses AB and DB are opened and while a peripheral device is performing the prescribed information processing with use of those buses. Such data processing includes the information processing such as a floating point operation, etc. which needs a comparatively long processing time with small data quantity. |
