Chapter 3
Hardware
22
Reference Manual
CoreModule 720
I/O Address Map
Table 3-3
shows the I/O address map. These are DOS-level addresses. The OS typically hides these physical
addresses by way of memory management.
Table 3-3. I/O Address Map
Address (hex)
Subsystem
0000-00F
Primary DMA Controller0
0020-0021
Master Interrupt Controller
0040-0043
Programmable Interrupt Timer (Clock/Timer)
0060-006F
Keyboard Controller
0070-007F
CMOS RAM, NMI Mask Reg, RT Clock
0080-009F
DMA Page Registers
00A0-00BF
Slave Interrupt Controller
00C0-00DF
Slave DMA Controller #2
00F0-00FF
Math Coprocessor
02E8-02EF
Serial Port 4 (COM3)
02F8-02FF
Serial Port 2 (COM1)
03B0-03BB
Video (monochrome)
03C0-03DF
VGA
03E8-03EF
Serial Port 3 (COM2)
03F8-03FF
Serial Port 1 (COM0)
0400-041F
SMBus Configuration Ports
0500-053F
PCH GPIO Configuration Ports
0800-087F
PCH Power Management Ports
0A79h
ISA PnP Ports
0CF8-0CFF
PCI bus Configuration Address and Data
NOTE
0A79h is the ISA PnP port used by the BIOS and an OS that supports this feature to
recognize ISA PnP (Plug and Play) cards.
The Intel I/O hub PCH EG20T does not support ISA DMA.