Sun Microsystems Netra T4 AC100, Руководство по обслуживанию и системе

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Chapter 10 Functional Description 10-23
Older PCI cards operate at 5 VDC, while newer cards are designed to operate at
3.3 VDC. Cards that require 5 VDC will not operate in 3.3-volt slots, and 3.3-volt
cards will not operate in 5-volt slots. “Universal” PCI cards are designed to operate
at either 3.3 VDC or 5 VDC, so these cards can be inserted into either type of slot. The
system provides three slots for 5-volt cards and one slot for a 3.3-volt card. All four
PCI slots accept universal cards.
Most PCI cards operate at clock speeds of 33 MHz, while newer EPCI cards operate
at 66 MHz. All four PCI slots can accept 33-MHz cards.
Note – Installing a 33-MHz card into a 66-MHz EPCI slot will slow system
performance.
66-MHz cards are restricted to the slot labelled EPCI 1. The following table lists the
mapping of the PCI slots to the two PCI buses, and the type of PCI cards supported
in each slot.
10.2.7.2 PCI Bus ASICs
SCSI Controller
The SCSI controller ASIC provides an interface between the 33-MHz PCI bus and the
internal and external SCSI buses. The dual SCSI bus controller provides separate
connections to internal and external devices. SCSI channel A is used for internal
devices and supports the SCSI fast and narrow mode. SCSI channel B is used for
external devices and supports the SCSI ultra-wide mode.
TABLE 10-2
PCI Slot-to-PCI Bus Mapping
Connector
Label
Conn. No. PCI Bus
Slot Width (bits)/
Card Type (bits) Clock Rates
(MHz) DC Voltage (VDC)/
Card Type
PCI 4 J2601 B 64/32 or 64 33 5/universal
PCI 3 J2501 B 64/32 or 64 33 5/universal
PCI 2 J2401 B 64/32 or 64 33 5/universal
PCI 66 1 J2301 A 64/32 or 64 66 3.3/universal