21154 PCI-to-PCI Bridge
.
Figure 1. 21154 on the System Board
PCI
Option Slots
CPU
21154
64-Bit PCI Bus
PCI
Option Slots
Core
Logic
Graphics
ISA or EISA
Option Slots
64-Bit
PCI Bus
21154
64-Bit PCI Bus
ISA or
EISA
SCSI
LAN
ISA or EISA Bus
Bridge
Support
Chip
Diskette
Keyboard
Serial
Parallel
TOY Clock
Audio
LJ-05428.AI4
Option card designers can use the 21154 to implement multiple-device PCI option cards. Without a
PCI-to-PCI bridge, PCI loading rules would limit option cards to one device. The PCI Local Bus
Specification loading rules limit PCI option cards to a single connection per PCI signal in the
option card connector. However, the 21154 overcomes this restriction by providing, on the option
card, an independent PCI bus to which up to nine devices can be attached.
Figure 2 shows how the 21154 enables the design of a multicomponent option card.
2
Datasheet
INTEL [ INTEL ]
