RadiSys EPC-26A/27, Руководство пользователя

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EPC-26A/27 Hardware Reference
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Memory Expansion
A single 72-pin SIMM socket is provided for memory expansion. A standard SIMM
module is used for expansion, and must meet the following criteria:
- 3.3 Volt
- fast page mode
- 72-pin
- 70 nanosecond DRAM or better
- single-sided or double-sided
There are four different 72-pin SIMM modules that can be installed into the SIMM
socket. The different sizes available are 4, 8, 16 and 32 MBytes.
Memory Map
The Intel DX2/DX4 SL Enhanced CPU supports a 32-bit physical memory address.
Memory at addresses between 0 and 32 MB is mapped as follows:
Range Content
0000000 - 009FFFFh
DRAM (first 640 KB)
00A0000 - 00BFFFFh Mapped to EXM expansion interface; almost always
used by a video controller as video RAM
00C0000 - 00C7FFFh Shadowed video BIOS (if video is used)
(write protected)
00C8000 - 00DFFFFh Mapped to EXM expansion interface
00E0000 - 00EFFFF System Upper Memory
00F0000 - 00FFFFFh Write-protected DRAM containing BIOS
0100000 - 13FFFFFh Extended memory when installed or mapped to EXM
expansion interface
1400000 - 1FEFFFFh Mapped to EXM expansion interface
1FF0000 - 1FFFFFFh Mapped to BIOS ROM
Table 3-2. Memory Map.
0C8000 - 0EFFFF may be used either as page frame, BIOS extension, I/O buffer
(i.e. for extended memory managers, Ethernet, etc.) or may be used by DOS as upper
memory blocks if an extended memory manager driver is installed.