
Configuring the SIMATIC Box PC 620
”Memory Cache” Submenu
The following
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Main |
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System Time: | [ 15:35:32 ] |
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System Date: | [ 03/12/2002 ] |
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Diskette A: | [1.44 MB, 31/2” ] | Controls caching of | |||||
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Primary Master | [20496 MB] |
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| memory and memory | ||||||
Primary Slave | [None] |
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| above one megabyte. | |||||
Secondary Master | [CD– |
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Secondary Slave | [None] | Disabled |
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| Write Through |
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Memory Cache: | [Write | Write Back |
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Boot Options |
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Keyboard Features |
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Hardware Options |
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System Memory: | 640 KB |
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Extended Memory: | 121856 MB |
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F1 | Help | Select Item | + / – | Change Values | F9 | Setup Defaults | |
ESC | Exit | Select Menu | Enter | Select | F10 | Save and Exit |
Figure 5-4 “Memory Cache” Field
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] | Cache is disabled |
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[Write Through] | Write access is not concluded until the entry has been made in main |
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[Write Back] | Write access is concluded immediately; the entry in main memory |
| takes place in the backround (default) |
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SIMATIC Box PC 620 Manual | |