As we saw earlier in the section on linux and segmentation , each segment descriptor uses same set of addresses for linear addressing , minimizing the need to use the segmentation unit to convert logical addresses to linear addresses 前面介绍linux分段模型时已提到,每个分段描述符都使用相同的地址集进行线性寻址,从而尽可能降低使用分段单元将逻辑地址转换成线性地址的需要。
Adopting the method of top - down , the virtual memory is divided into memory mange related unit ( segment unit and page unit ) and protection mode related unit ( protection test unit , debug test unit and exception detect unit ) . data buses and control bused are designed separately for all of the units . vhdl codes are written and simulated Amex86的虚拟存储器采用自顶向下的设计方法,把虚拟存储器划分为地址管理相关单元(又包括分段单元和分页单元) 、保护模式相关单元(又包括保护测试单元、调试异常单元利异常检测单元等) ,分别确立其数据通路和控制通路,完成了vhdl的编码和仿真工作,通过测试程序仿真验证了其功能的正确性并测定了基本性能。