2-6 P55-IT
2-5 Integrated PCI Bridge
The
P55-IT
utilizes
Intel's Triton 82430 PCIset
chipset to support Intel Pentium
P54C/P54CS/P55C/P55CT Processor PCI/ISA system. The Intel Triton 82430FX
PCIset chipset consists of the 82437FX Triton system controller (TSC), two
82438FX Triton Data Path (TDP) devices, and one 82371FB PCI ISA/IDE Accel-
erator (PIIX) bridge chip. It provides an interface which translates CPU cycle into
PCI bus cycle, and PCI burst read/write capability. In addition, it provides high
performance PCI arbitor to support four PCI Masters, Rotating Priority Mecha-
nism, and Hidden Arbitration Scheme Minimizes Arbitration Overhead.
There are four interrupts in each PCI slot : INTA#, INTB#, INTC#, and INTD#.
Since the
P55-IT
adapts the PCI auto-configuration with the system BIOS Setup
utility. When the system is turned on after adding a PCI add-in card, the BIOS
automatically configure interrupts, DMA channels, I/O space, and other
paramaters. You do not have to configures jumpers or worry potential resource
conflicts. Because PCI cards use the same interrupt resource as ISA cards, you must
specify the interrupt used by ISA add-in cards in the BIOS Setup utility.
If however, a "Legacy card" (such as plug paddle card and cable into the ISA slot.)
is plugged in the system, modification in the
ROM SETUP UTILITY
become
necessary. First, enter
PCI CONFIGURATION SETUP
utility from
ROM
SETUP UTILITY
main menu to set the "
PCI IDE IRQ MAP TO
:
ISA
".
Second, you must be enter
CHIPSET FEATURES SETUP UTILITY
from
ROM
SETUP UTILITY
main menu and set the "
Onboard Primary PCI IDE: Disabled
and
Onboard Secondary PCI IDE: Disabled
." When you plugged the PCI/ISA
IDE card into the system. You will
Disabled Onboard Primary and Secondary
PCI IDE
from
CHIPSET FEATURES SETUP UTILITY
too.
Some "Legacy card" ( no paddle card and cable.) you can set the system interrupt
request (IRQ) on the "Legacy card" (refer to user's manual of the card) to a proper
system IRQ level (in general, card's Primary assigned to INTA and Secondary
assigned to INTB). If the card is plugged into slot 1(marked PCI#1), you can not
use second slot (marked PCI#2) because the Secondary INT signal takes INTB
from the slot (refer to Page 3-12 for circuit diagram). The user then enter
PCI
CONFIGURATION SETUP
utility from
ROM SETUP UTILITY
main menu
and set the "
PCI IDE IRQ MAP TO
:
PCI-Slot 1
" (depend on the slot # where the
Legacy card is plugged).
.
