Detailed descriptions
16.4 System resources
SIMATIC Rack PC 840 V2
Operating Instructions, Edition 05/2006, A5E00248055-04
16-21
16.4.2.3 Memory address assignments
PCI VGA modules can be operated with an expansion ROM of a size up to 48 K.
Address
from
up to
Size
Description of the basic
function
Possible alternative
function
0000 0000
0007 FFFF
512K
Conventional system
memory
0008 0000
0009 F7FF
127k
Conventional system
memory extended
0009 F800
0009 FFFF
2K
XBDA, extended Bios Data
Area
000A 0000
000A FFFF
64K
VGA graphics refresh
memory
Shared SMM for power
management
000B 0000
000B 7FFF
32K
Monochrome graphics/text
refresh memory
Unused
000B 8000
000B FFFF
32K
VGA graphics/text refresh
memory
000C 0000
000C BFFF
48K
VGA-BIOS expansion
000C C000
000C FFFF
16K
USB
Always occupied
000D 0000
000E 7FFF
96K
1)
unused (device driver or ISA
hardware)
via EMM High DOS
Memory
000D 0000
000D 97FF
38K
2)
RAID
000D 0000
000D 93FF
37K
2)
SATA RAID
000D 9400
000E 97FF
65K
2)
Unused
000D 9800
000E 97FF
64K
2)
Unused
000D 0000
000D 65FF
26K
2)
SCSI
000D 65FF
000E 97FF
76K
2)
Unused
000E 8000
000F FFFF
96K
2)
System BIOS
000E 9800
000F FFFF
96K
2)
System BIOS
0010 0000
00EF FFFF
14M
System memory
00F0 0000
00FF FFFF
16M-15M=1M System memory or memory
hole
Via ISA memory setup
(memory hole)
0100 0000
7FFF FFFF
Max. 2 GB -
16 MB
System memory, 512
Kbytes of top of memory are
reserved for USB.
Depends on memory
configuration
7000 0000
FFF7 FFFF
PCI memory address space For PCI expansion
cards
FFF8 0000
FFFF FFFF
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