Compaq GS80, GS160, GS320 manual PCI Boxes, Sample I/O Subsystem

3.8PCI Boxes

A QBB supports up to two PCI boxes. A cable connects the QBB “local” I/O riser to the “remote” I/O riser in the PCI box. There are two I/O ports on a local I/O riser. Each I/O port is used to connect to one remote I/O riser. Figure 3–10 shows QBB0 connected to PCI box 0 and PCI box 1.

Figure 3–10 Sample I/O Subsystem

PCI Box 0

	PCA
PCI Bus	Chip
	PCI Bus
		PCA
		Chip
	PCI Bus	PCI Bus

Remote I/O	Remote I/O
Riser 1	Riser 0

PCI Box 1

	PCA
PCI Bus	Chip
	PCI Bus
	PCA
	Chip
	PCI Bus	PCI Bus

Remote I/O	Remote I/O
Riser 1	Riser 0

10 Local I/O Riser

32 Local I/O Riser

QBB0

PK-0652-99

3-18AlphaServer GS80/160/320 User’s Guide