28 CPCI-7806/CPCI-7806RC Pentium/Celeron M Universal CompactPCI Single Board Computer
Publication No. 500-657806-000 Rev. G
2.3 I/O Port Map
Like a desktop system, the CPCI-7806/CPCI-7806RC include special input/output
instructions that access I/O peripherals residing in I/O addressing space (separate
and distinct from memory addressing space). Locations in I/O address space are
referred to as ports. When the CPU decodes and executes an I/O instruction, it
produces a 16-bit I/O address on lines A00 to A15 and identifies the I/O cycle with
the M/I/O control line. Thus, the CPU includes an independent 64 Kbyte I/O
address space, which is accessible as bytes, words or longwords.
Standard hardware circuitry reserves only 1,024 byte of I/O addressing space
from I/O $000 to $3FF for peripherals. All standard PC I/O peripherals, such as
serial and parallel ports, hard and floppy drive controllers, video system, real-
time clock, system timers and interrupt controllers are addressed in this region of
I/O space. The BIOS initializes and configures all these registers properly;
adjusting these I/O ports directly is not normally necessary.
The assigned and user-available I/O addresses are summarized in the I/O Address
Map,
Table 2-1 CPCI-7806/CPCI-7806RC I/O Address Map
I/O ADDRESS RANGE SIZE IN BYTES
HW DEVICE PC/AT FUNCTION
$000 - $00F
16
DMA Controller 1 (Intel 8237A Compatible)
$010 - $01F
16
Reserved
$020 - $021
2
Master Interrupt Controller (Intel 8259A Compatible)
$022 - $03F
30
Reserved
$040 - $043
4
Programmable Timer (Intel 8254 Compatible)
$044 - $05F
28
Reserved
$060 - $064
5
Keyboard, Speaker, System Configuration
(Intel 8042 Compatible)
$065 - $06F
11
Reserved
$070 - $071
2
Real-Time Clock
$072 - $07F
14
Reserved
$080 - $08F
16
DMA Page Registers
$090 - $091
2
Reserved
$092
1
Alt. Gate A20/Fast Reset Register
$093 - $09F
11
Reserved
$0A0 - $0A1
2
Slave Interrupt Controller (Intel 8259A Compatible)
$0A2 - $0BF
30
Reserved
$0C0 - $0DF
32
DMA Controller 2 (Intel 8237A Compatible)
$0E0 - $16F
142
Reserved
$170 - $177
8
6300ESB
Secondary Hard Disk Controller
$178 - $1EF
120
User I/O
$1F0 - $1F7
8
6300ESB
Primary Hard Disk Controller
$1F8 - $277
128
User I/O
$278 - $27F
8
I/O Chip*
LPT2 Parallel I/O*
$280 - $2E7
104
Reserved
$2E8 - $2EE
7
6300ESB
COM4 Serial I/O*
$2EF - $2F7
9
User I/O