The development of multi-tasking application and architecture improvement introduce the need of virtual memory management in embedded processors. Virtual memory management is implemented through a hardware memory management unit ( MMU ) that supports address translation and protection on the fly. 随着体系结构的不断发展和多任务嵌入式系统的开发,嵌入式处理器需要提供虚拟内存管理的支持,虚拟内存管理是通过内存管理单元硬件实现在系统运行时的地址转换和地址空间保护。