分段分页和分页分段之间的区别或相似之处? [英] Differences or similarities between Segmented paging and Paged segmentation?

问题描述

我正在研究组合式分页/分段系统，在我的书中，有两种方法可以解决此问题:

I was studying combined paging/segmentation systems and in my book there were two approaches to this :

1.paged segmentation
2.segmented paging

我无法分辨两者之间的区别.我认为在分页细分中，该细分分为页面，而在分页分页中，该页面又分为细分，尽管我不知道我是对还是错.同时，在因特网上，仅使用一种方案来描述组合的寻呼/分段.我不知道为什么在我的课程手册中有两种方案.任何帮助将不胜感激.

I could not make out the difference between the two. I think in paged segmentation the segment is divided into pages and in segmented paging the pages are divided into segments, though I don't know if I am right or wrong. Meanwhile on the internet the combined paging/segmentation is described using one scheme only. I can't figure out why in my coursebook there are two schemes for this. Any help would be deeply appreciated.

推荐答案

因此，在大力搜索这两个术语之间的区别或相似之处之后，我得出了最终答案.首先，我要写下来相似之处:

So,after vigorously searching on net for the difference or similarity between these two terms,I have come up on a final answer.First of all I would write down the similarities:

• 它们(分段分页和分页分段)都是寻呼/分段组合系统的一种(分页和分段可以通过将每个分段分成页面来组合).
• 在两个系统中，细分都分为几页.

现在要描述差异，我将不得不分别定义和描述每个术语:

Now to describe the differences I will have to define and describe each term separately:

• 分段分页-分段分为页面.实现需要STR(段表寄存器)和PMT(页面映射表).在此方案中，每个虚拟地址均由段号组成，该段内的页码和该页内的偏移量.段号索引到段表中，从而产生该段的页表的基地址页码索引到页表中，每个表项都是页框.将PFN(页框号)和偏移量相加会得到物理地址.因此可以通过以下功能来描述寻址:

• Segmented paging- Segments are divided into pages.Implementation requires STR(segment table register) and PMT(page map table).In this scheme, each virtual address consists of a segment number, page number within that segment and an offset within that page.The segment number indexes into segment table which yields the base address of the page table for that segment.The page number indexes into the page table,each of which entry is a page frame.Adding the PFN(page frame number) and the offset results in the physical address.Hence addressing can be described by the following function :

va =(s，p，w)其中，va是虚拟地址，| s |确定数量 段(ST的大小)，| p |确定每段的页数(大小为 PT)，| w |确定页面大小.

va = (s,p,w) where, va is the virtual address, |s| determines number of segments (size of ST), |p| determines number of pages per segment (size of PT), |w| determines page size.

address_map(s, p, w)
{
pa = *(*(STR+s)+p)+w;
return pa;
}

图在这里:

• 分页分段-有时，分段表或页表可能太大而无法保存在物理内存中(它们甚至可以达到MB).因此，分段表也被分为几页，因此有一个页表的ST页已创建. 段号分为ST页的页表的页号(s1)和页偏移量(s2).地址可以描述为:

• Paged Segmentation- Sometimes segment table or page table may too large to keep in physical memory(they can even reach MBs).Therefore,the segment table is divided into pages too and thus a page table of ST pages is created. The segment number is broken into page no.(s1) and page offset(s2) of page table of ST pages.So,the virtual address can be described as :

va =(s1，s2，p，w)

address_map
(s1, s2, p, w)
{
pa = *(*(*(STR+s1)+s2)+p)+w;
return pa;
}

图的描述在这里:

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