Registers
http://www.motorola.com/computer/literature
2-57
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The register fields are defined as follows:
REG
Register Number.
Configuration Cycles: Identifies a target double word within a
target’s configuration space. This field is copied to the PCI AD bus
during the address phase of a Configuration cycle.
Special Cycles: This field must be written with all zeros.
FUN
Function Number.
Configuration Cycles: Identifies a function number within a
target’s configuration space. This field is copied to the PCI AD bus
during the address phase of a Configuration cycle.
Special Cycles: This field must be written with all ones.
DEV
Device Number.
Configuration Cycles: Identifies a target’s physical PCI device
number. Refer to
for a
description of how this field is encoded.
Special Cycles: This field must be written with all ones.
BUS
Bus Number.
Configuration Cycles: Identifies a targeted bus number. If written
with all zeros, a Type 0 Configuration Cycle will be generated. If
written with any value other than all zeros, then a Type 1
Configuration Cycle will be generated.
Special Cycles: Identifies a targeted bus number. If written with all
zeros, a Special Cycle will be generated. If written with any value
other than all zeros, then a Special Cycle translated into a Type 1
Configuration Cycle will be generated.
EN
Enable.
Configuration Cycles: Writing a one to this bit enables
CONFIG_DATA to Configuration Cycle translation. If this bit is a
zero, subsequent accesses to CONFIG_DATA will be passed
though as I/O Cycles.
Special Cycles: Writing a one to this bit enables CONFIG_DATA
to Special Cycle translation. If this bit is a zero, subsequent
accesses to CONFIG_DATA will be passed though as I/O Cycles.