GT-64260A Design Guide
Doc. No. MV-S300165-00, Rev. A
CONFIDENTIAL
Copyright © 2002 Marvell
Page 48
Document Classification: Proprietary Information
May 21, 2002, Preliminary
•
2ndBusL - Secondary PCI Interface Bus Range Lower Boundary
•
2ndBusH - Secondary PCI Interface Bus Range Upper Boundary
•
BusNum - The PCI bus number to which the PCI interface is connected.
5.2
PCI Arbitration
The GT-64260A supports either external arbiter or internal arbiter configurations through the PCI Arbiter Control
register’s
EN
bit [31], at offsets 0x1d00 and 0x1d80. If the bit is set to ‘1’, the internal PCI bus arbiter is enabled.
Each PCI interface can be configured separately to a different PCI arbiter configuration.
5.2.1 Internal PCI Arbiter
When the internal arbiter is enabled the GT-64260A PCI arbiter REQ*/GNT* pins are multiplexed on the MPP
pins. Each internal PCI arbiter (PCI0 and PCI1) supports up to six external PCI devices and the GT-64260A PCI
device (seven PCI devices per PCI interface).
shows the internal PCI arbiter multiplexing.
Note
The multiplexing for PCI0 and PCI1 interfaces are the same.
BusNum
0
1
1
2
3
1
Table 12:
Internal PCI Arbiter in Multiplexing
PCI Pins
Optional Multiplexing on MPP Pins
REQ0*
MPP1
MPP17
GNT0*
MPP0
MPP16
REQ1*
MPP3
MPP19
GNT1*
MPP2
MPP18
REQ2*
MPP5
MPP21
GNT2*
MPP4
MPP20
REQ3*
MPP7
MPP23
MPP15
MPP31
GNT3*
MPP6
MPP22
MPP14
MPP30
REQ4*
MPP9
MPP25
MPP13
MPP29
GNT4*
MPP8
MPP24
MPP12
MPP28
Table 11:
PCI P2P Configuration Register Initialization Example
GT-64260A #1
GT-64260A #2
GT-64260A #3
PCI0
PCI1
PCI0
PCI1
PCI0
PCI1