User manual

Kontron Compact Computers AG SMX945 Detailed Manual V1.1

3.4. CMOS RAM Map

Systems based on the industry-standard specification include a battery backed Real Time Clock chip. This

clock contains at least 64Bytes of non-volatile RAM. The system BIOS uses this area to store information

including system configuration and initialization parameters, system diagnostics, and the time and date. This

information remains intact even when the system is powered down.

The BIOS supports 128Bytes of CMOS RAM. This information is accessible through I/O ports 70h and 71h.

CMOS RAM can be divided into several segments:

 Locations 00h - 0Fh contain real time clock (RTC) and status information

 Locations 10h - 2Fh contain system configuration data

 Locations 30h - 3Fh contain System BIOS-specific configuration data as well as chipset-specific

information

 Locations 40h - 7Fh contain chipset-specific information as well as power management configuration

parameters

3.5. System Memory Map

The PENTIUM CPU, used as a central processing unit on the MICROSPACE, has a memory address

space which is defined by 32 address bits. Therefore, it can address 4GBytes of memory. The memory

address map is as follows:

CPU Pentium

Address Size Function / Comments

000000 - 09FFFFh 640kBytes Onboard DRAM for DOS applications

0C0000 - 0CBFFFh

0CC000 - 0CFFFFh

48kBytes

16kBytes

VGA BIOS, selected by the hardware

BIOS extensions, selected by the hardware

0D0000 - 0D4000h

0D4000 - 0D8000h

0D8000 - 0DFFFFh

16kBytes

32kBytes

Free for user

0E0000 - 0FFFFFh 1024kBytes Core BIOS, selected by the 945GM chipset

100000 - 1FFFFFh 1MByte DRAM for extended onboard memory

200000 - FFFFFFh 14MBytes DRAM for extended onboard memory