Siemens Simatic 620 Owner's Manual page 97

"Memory Cache" Submenu
The following pop-up menu appears when you select the submenu "Memory
cache" in the main menu:
F1
ESC
Figure 5-4
A cache is a fast memory buffer between the CPU and main memory (DRAM).
Recurrent memory access operations are executed in the fast cache, instead of
the main memory, if the function is enabled. In rare instances involving some
hardware and software combinations, it may be necessary to disable the cache
because the program runtimes or waits are too short on account of the fast cache.
[Disabled]
[Write Through]
[Write Back]
SIMATIC Box PC 620 Manual
A5E00131465-01
PhoenixBIOS Setup Utility
Main
System Time: [ 15:35:32 ]
[ 03/12/2002 ]
System Date:
Diskette A: [1.44 MB, 31/2" ]
Primary Master [20496 MB]
Primary Slave [None]
Secondary Master [CD–ROM]
Secondary Slave [None]
[Write Back]
Memory Cache:
Boot Options
Keyboard Features
Hardware Options
System Memory: 640 KB
Extended Memory: 121856 MB
Help Select Item
Exit Select Menu
"Memory Cache" Field
Cache is disabled
Write access is not concluded until the entry has been made in main
memory
Write access is concluded immediately; the entry in main memory
takes place in the backround (default)
Configuring the SIMATIC Box PC 620
Item Specific Help
Controls caching of
system conventional
memory and memory
above one megabyte.
Disabled
Write Through
Write Back
+ / – Change Values F9
Select
Enter
Sub-Menu F10
Setup Defaults
Save and Exit
5-9