EBX-22 Reference Manual
70
System Resources and Maps
Memory Map
The lower 1 MB memory map of the EBX-22 is arranged as shown in the following table.
Table 35: Memory Map
Start Address End Address
Comment
E0000h
FFFFFh
System BIOS
D0000h
DFFFFh
PCI or ISA BIOS
extensions or boot ROMS
C0000h
CFFFFh
Video BIOS
A0000h
BFFFFh
Video RAM
00000h
9FFFFh
System RAM
I/O Map
The following table lists the common I/O devices in the EBX-22 I/O map. User I/O devices
should be added with care to avoid the devices already in the map shown in below.
Table 36: I/O Map
I/O Device
Standard I/O Addresses
Reserved
1B0h – 1BFh
ADC Data Registers
1C0h – 1CFh
PLED and Product ID Register
1D0h
Revision and Type Register
1D1h
Video BIOS Select Register
1D2h
Reserved 1D3h
GPO 1D4h
ADC, DIO, SPI Bit Bang Registers
1D5h – 1D7h
Legacy SPI interface
1D8h – 1DDh
IRQ, Resource ISA Enable Registers
1DEh
SPI, DIO, ADC Mode Register
1DFh
Watchdog Timer
1E0h – 1E3h
Primary Hard Drive Controller
1F0h – 1F7h
COM4 Serial Port
2E8h – 2EFh
LPT1 Parallel Port
378h – 37Fh
COM3 Serial Port
3E8h – 3EFh
COM2 Serial Port
2F8h – 2FFh
COM1 Serial Port
3F8h – 3FFh
Note
The I/O ports occupied by on-board devices are freed up when the device is
disabled in CMOS Setup. This does not apply to SPI and reserved registers.
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