Siemens SIMATIC RI 45 PIII Series, Руководство пользователя

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2-40
RI 45 PIII, Manual
C79000-G7076-C817-01
The following pop-up menu appears when you select the option “Memory
cache” in the main menu:
PhoenixBIOS Setup Utility
Item Specific Help
System Time:
F1
ESC
Help
Exit
System Date:
[ 15:35:32 ]
Select Item
Select Menu
+ / -
Enter Select
Change Values
Sub-Menu
F9
F10
Setup Defaults
Save and Exit
Diskette A:
[ Disabled ]
Diskette B:
[ Disabled ]
Primary Master
[8455MB]
Primary Slave
[8455 MB]
Memory Cache:
Boot Options
Keyboard Features
[Write
Hardware Options
System Memory:
Extended Memory:
Main Security Power Version Advanced
Secondary Master
[CD-ROM]
Secondary Slave
[None]
[ 04/05/1999 ]
640 KB
64512 KB
Controls caching of system
conventional memory and
memory above one megabyte
Disabled
Write Through
Write Back
Exit
Boot Sequence
Figure 2-13 “Memory Cache” Submenu
A cache is a fast intermediate memory located between the CPU and the
memory (DRAM). Repeated memory access operations are executed in the
fast cache, and not in the main memory, provided the feature is enabled. It
may be necessary to disable the cache with certain hardware and software
because intentional program runtimes or delay times are prevented by the fast
cache.
[Disabled] Cache is disabled.
[Write Through] Write access is only concluded when an entry is made in the
main memory.
[Write Back] Write access is concluded immediately, the entry in the RAM
takes place in the background.
Option “ Memory
Cache”
Motherboard