SECOMX-945/N270
User Manual
- Rev. First Edition: 0.1 - Last Edition: 2.1 - Author: S.B. - Reviewed by G.M.
Copyright © 2011 SECO s.r.l.
SECOMX-945/N270
pag. 36
4.7 I/O MAPPING - IRQ
4.7.1 ISA Addressing
On conventional ISA bus, addressing space ranges from 00 Hex to 3FF Hex: some of these I/O
addresses are occupied by system resources, therefore they cannot be used for direct I/O access.
Please notice, however, that free I/O addresses can change, since PCI dynamical allocation can
occupy some of the spaces that are left from BIOS settings. Disabling, via BIOS, some resources
can also free some I/O addresses. Finally, additional I/O addresses can be occupied by non-
standard devices placed on the Carrier Board of SECOME-945/N270 module.
Therefore, for an exhaustive list of I/O addresses used, it is better to look into your O.S. Device
Manager, to see what addresses are effectively free
Here following, however, there is a list of addresses usually occupied for system resources.
Device
Range
Note
0x00-0xFF
RESERVED FOR MOTHERBOARD PRIMARY RESOURCES
IDE1 Master
0x170-0x177
Available if Internal IDE/SATA Mode is set to Disabled
IDE0 Master
0x1F0-0x1F7
Available if Internal IDE/SATA Mode is set to Disabled
COM2
0x2F8-02xFF
Available if "Internal COMB base address" is "Disabled" via Setup
IDE1 Slave
0x376-0x377
Available if Internal IDE/SATA Mode is set to Disabled
LPT
0x378-0x37F
Available if "Internal LPT" is "Disabled" via Setup
VGA standard
0x3B0-0x3DF
Available if "Internal video memory Mb" is "Off" via Setup and there is not
any additional video board
FDC
0x3F0-0x3F7
A
vailable if “FDC Controller” is Disabled via Setup
IDE0 Slave
0x3F6-0x3F7
Available if Internal IDE/SATA Mode is set to Disabled
COM1
0x3F8-0x3FF
Available if "Internal COMA base address" is "Disabled" via Setup
0x400-0x47F
RESERVED FOR MOTHERBOARD PRIMARY RESOURCES
0x4D0-0x4D1
RESERVED FOR MOTHERBOARD PRIMARY RESOURCES
0x800-0x80F
RESERVED FOR MOTHERBOARD PRIMARY RESOURCES
PCI / PCIe
0xCF8-0xCFF
PCI configuration register
PCI / PCIe Devices
0x1000-0xEFFF
PCIO BIOS starts to assign I/O resources from 0xFFF0 downwards
0x162E-0x162F
RESERVED FOR SUPER I/O CONFIGURATIONS
0x164E-0x164F
RESERVED FOR SUPER I/O CONFIGURATIONS
0xF000-0xFFFF
RESERVED FOR MOTHERBOARD PRIMARY RESOURCES
