CME136686LX Hardware Manual - RTD Embedded Technologies ...

Memory Map
The CME136686LX is a 32-bit processor with a 4GB address space (0x00000000 through 0xFFFFFFFF). The first
one megabyte of memory follows the standard x86 PC architecture, which is listed below.
WARNING Installing a peripheral that conflicts with any of the addresses listed below may prevent
the system from functioning!
Table 38
Memory Addresses Reserved for the CME136686LX cpuModule
Memory Address
Range
Device
0x00000 - 0x003FF Interrupt Vectors
0x00400 - 0x004FF BIOS Data Area
0x00500 - 0x9FFFF DOS and User Applications
0xA0000 - 0xBFFFF EGA/VGA Video Buffer
0xC0000 - 0xC7FFF Geode LX VGA BIOS
0xC8000 - 0xC9FFF PXE Firmware (address may vary) 1
0xD0000 - 0xDFFFF (Available for Memory Mapped ISA Boards)
0xE0000 - 0xFFFFF BIOS
1. The location of the PXE Firmware is dynamically allocated by the BIOS at boot time.
It uses 8KB, and is typically located at 0xC8000. However, this can change based on
BIOS settings and other devices in the system. If Ethernet is disabled, the PXE
Firmware will be removed from the memory map.
Memory addresses beyond the first megabyte can be accessed either via Protected Mode or a memory manager
such as EMS. Consult your Operating System programming documentation for more information.
Note When installing a memory-mapped ISA peripheral, make sure that the PCI-to-ISA Bridge is
configured correctly. Refer to Using ISA Peripheral Cards on page 64.
Note The cpuModule has onboard PCI devices (e.g. Ethernet) that may claim I/O resources not listed
above. Memory mapped PCI devices are typically located above 80000000h to prevent conflicts with
legacy ISA devices. Since PCI devices are dynamically configured at boot time, their memory addresses
are not fixed.
BDM-610000065 Rev C Chapter 4: Using the cpuModule 61