Motorola M68000 User's Guide download pdf (Page 227)

The 68030 213

3. Each cache is 256 bytes.

4. A write-through is used. Whenever a data location is modified in the

cache, it is also modified in the corresponding memory location.

5. Three.

6. Pipelining is a technique that allows more than one instruction to be

executing at a time.

7. The 68030 instruction pipe is three words long.

8. The 68030 PMMU implements a sophisticated version of paging.

9. A logical address consists of a page number and an offset into the

page.

10. A frame is a unit of the physical memory that corresponds in size to

a page in the logical address space. A frame can be used to hold any

page.

11. An exception is generated so that the operating system can find the

missing page on secondary storage, bring it into memory, and then

allow the program to continue.

12. The page number is used as an index into a page table where the

actual physical location (frame) of the page is found.

13. The ATC is used to speed up the process of page mapping by keeping

current mappings in fast internal associative memory.

14. The ATC can hold 64 mappings.

15. Locality of reference is the property of a program that results in

references to only a small portion of its total addressing space over

particular intervals of time.

16. A working set is the set of pages a program is currently referencing.

This is normally a subset of the total number of pages. The working

set slowly changes as the program advances.

17. Translation descriptors.

18. A rooted tree.

19. Four.

20. By use of the CPU root pointer, CRP, or the supervisor root pointer,

SRP. These are registers available in supervisor mode only.

1 2 ... 222 223 224 225 226 227 228 229 230 231 232 ... 255 256

No comments

Motorola M68000 User's Guide Page 227