Artesyn ATCA-7350 Installation and Use (September 2014) - Manual (Page 169)

Addressing
ATCA-7350 Installation and Use (6806800G59G) 169
9.2 Configuration Registers
9.2.1 Configuration Address Register MCH CONFIG_ADDRESS
Default Value: 0x00000000
Access: Read/Write
Size: 32 bits
CONFIG_ADDRESS is a 32-bit I/O register that can only be accessed as a Dword. A byte or word
reference passes through the Configuration Address Register and hub link interface HI_A onto
the PCI_A bus as an I/O cycle. The CONFIG_ADDRESS register contains the Bus Number, Device
Number, Function Number, and Register Number for which a subsequent PCI configuration
access is intended. This register is defined by the PCI Bus specification.
Table 9-2 I/O Address: 0x0CF8 Accessed as a Dword
Bit Description
31 Configuration Enable (CFGE): When this bit is set to 1, accesses to PCI
configuration space are enabled. When this bit is reset to 0, accesses to PCI
configuration space are disabled.
30:24 Reserved (These bits are read only and have a value of 0).
23:16 Bus Number: Contains the bus number being targeted by the configuration
cycle.
15:11 Device Number: Selects one of the 32 possible devices per bus.
10:8 Function Number: Selects one of eight possible functions within a device.
7:2 Register Number: This field selects one register within a particular Bus, Device,
and Function as specified by the other fields in the Configuration Address
Register. This field is mapped to A[7:2] during HI_A-D Configuration cycles.
Table 9-3 Configuration address register bit assignments
Bit 31 30 24 23 16 15 11 10 8 7 2 1 0
0 R 0 0 0 0 R Default