Siemens SIMATIC Field PG P4 Manual page 76

Configuring the SIMATIC Field PG P4
"Memory Cache" Field
The following pop-up menu appears when you select the option "Memory cache" in
the main menu:
Fig. 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
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]
5-8
PhoenixBIOS Setup Utility
Main Advanced Security
System Time: [ 15:35:32 ]
System Date:
[ 02/06/2003]
Diskette A: [ 1,44MB 3 1/2" ]
Primary Master [10056MB]
Primary Slave [None]
Secondary Master [CD-ROM]
Secondary Slave [None]
[Write
Memory Cache:
Boot Options
Keyboard Features
Hardware Options
System Memory:
Extended Memory: 128511 KB
F1 Help Select Item
ESC Exit Select Menu
"Memory Cache" Menu
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 background (default)
Power Boot Version
Item Specific Help
Controls caching of
system conventional
memory and memory
above one megabyte.
Disabled
Write Through
Write Back
Back]
640 KB
+ / – Change Values F9
Enter Select
Sub-Menu F10
SIMATIC Field PG P4 Manual
Exit
Setup Defaults
Save and Exit
A5E00180080-04