Chapter 3 Hardware Description
3.8 I/O Port Address Map
Each peripheral device in the system is assigned a set of I/O port addresses which also becomes the identity of the device. There are a total of 1K port address space available. The following table lists the I/O port addresses used on the motherboard.
| Address |
|
| Device Description |
|
| 000h - 01Fh |
| DMA Controller #1 |
| |
| 020h - 03Fh |
| Interrupt Controller #1 |
| |
| 040h - 05Fh |
| Timer |
| |
| 060h - 06Fh |
| Keyboard Controller |
| |
| 070h - 07Fh |
| Real Time Clock, NMI |
| |
| 080h - 09Fh |
| DMA Page Register |
| |
| 0A0h - 0BFh |
| Interrupt Controller #2 |
| |
| 0C0h - 0DFh |
| DMA Controller #2 |
| |
| 0F0h |
| Clear Math Coprocessor Busy Signal |
| |
| 0F1h |
| Reset Math Coprocessor |
| |
| 1F0h - 1F7h |
| IDE Interface |
| |
| 278 - 27F |
| Parallel Port #2 (LPT2) |
| |
| 2F8h - 2FFh |
| Serial Port #2 (COM2) |
| |
| 2B0 - 2DF |
| Graphics adapter Controller |
| |
| 378h - 3FFh |
| Parallel Port #1(LPT1) |
| |
| 360 - 36F |
| Network Ports |
| |
| 3B0 - 3BF |
| Monochrome & Printer adapter |
| |
| 3C0 - 3CF |
| EGA adapter |
| |
| 3D0 - 3DF |
| CGA adapter |
| |
| 3F0h - 3F7h |
| Floppy Disk Controller |
| |
| 3F8h - 3FFh |
| Serial Port #1 (COM1) |
| |
3.9 DMA Channels
There are seven DMA Channels available on the motherboard. Only DMA2 is used by the floppy controller. In the case that ECP mode on the parallel port is used, DMA1 or DMA3 will be used.
10 | AI5VG Pentium VP3 Baby AT Motherboard User’s Manual |