The 845E-ANT MAINBOARD
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DRAM RAS# Precharge
If the DRAM is not continually refreshed it’s data will be lost. DRAM is normally
refreshed as a result of a single request. This field lets you select the number
of CLKs allocate for the RAS to accumulate its charge before the DRAM is re-
freshed. If there is not sufficient time then the refresh may be incomplete and
some of the data can be lost.
DRAM Data Integrity Mode
Error Checking and Correction (ECC) should only be used in conjunction with a
special 72-bit ECC RAM. If you are using ECC RAM you should select ECC.
This feature will enable the system to detect and correct single-bit errors and
detect (not correct) double-bit errors. If you do not have ECC RAM then select
Non-ECC (the default mode).
Memory Frequency For
This field allows you to manually select the frequency of the memory modules
you are using. This mainboard supports both PC100 and PC133 SDR modules.
If you do not know what the frequency of your memory modules is then select
auto and the system will automatically decide.
System BIOS\ Video BIOS Cacheable
These fields enable (disable) the caching of the System BIOS and the Video
BIOS. The Sysem BIOS is cached at F0000h-FFFFFh, and the Video BIOS is
cached at C0000h-C7FFFh, Both System and Video BIOS are cached via the L2
cache. If these options are enabled, access to the system BIOS may speed up
BUT if any other program tries to write to the memory locations specified
above then the system will crash. We recommend that you disable these op-
tions. Note The System/Video BIOS can only be cached when the System
BIOS/Video BIOS has been shadowed.
Memory Hole At 15M-16M
Some old add-in cards need this enabled to work properly. If you have such a
card then enable this, otherwise disable it.
Delayed Transaction
The chipset has an embedded 32-bit posted write buffer to support delay
transactions cycles. Select Enabled to support compliance with PCI
specification version 2.1.
AGP Aperture Size
This field selects the size of the Accelerated Graphics Port (AGP) aperture. The
aperture is a portion of the PCI memory address range dedicated for graphics
memory address space. Host cycles that hit the aperture range are forwarded
to the AGP without any translation. The default is 64MB. You may increase this
memory when you need to have faster access for 3D graphics applications (e.
g. games).
Managing The PC BIOS
