| 摘要 |
PURPOSE:To economically protect a memory without applying excess load to software by switching a current bank to a corresponding bank only when an external memory card is accessed, and when the memory card is not accessed, switching the current bank to an unused bank. CONSTITUTION:When a memory card access request is generated from an application, an operating system (OS) 200 switches the memory bank used by the memory card 43 for the hardware of a handy terminal. After completing said operation, the CPU 1 can be allowed to access the memory card 43. After completing the access to the memory card 43, the OS 200 immediately switches the current bank to an unused bank and then returns the control to the application. Consequently, memory protection can be economically attained without applying excess load to the software. |
