Broadcom BCM5722 - Figure 38: Header Type Register 0 Xe

BCM5722 Programmer’s Guide
10/15/07
Broadcom Corporation
Page 109 Configuration Space Document 5722-PG101-R
The following components are involved in BCM5722 Ethernet controller configuration space mapping:
• Base Address registers
• Standard mode map mode
• Flat memory map mode
• Indirect access mode
• Configuration space header
• Host memory
• MAC registers
• MAC local memory
FUNCTIONAL OVERVIEW
PCI Configuration Space Registers
The BCM5722 Ethernet controller configuration space can be broken into two regions: Header and Device Specific. Table 92
on page 186 shows the registers implemented to support PCI/PCI-X/PCIe functionality in the BCM5722 Ethernet controller.
Reserved fields in PCI configuration registers will always return zero.
PCI Required Header Region
The bit-7 of the Header Type register (Offset 0x0E) in the PCI Required Header Region is used to identify whether the device
is a single function device or multifunction device.
Figure 38: Header Type Register 0xE
Single function PCI devices may decode access to non-implemented device functions in two ways, per Section 3.2.2.3.4 of
the PCI 2.2 specification:
• A single function device may optionally respond to all function numbers as the same.
• May decode the function number field and respond only to function 0.
The BCM5722 Ethernet controller single function chips follow the stated technique #1— BIOS code scanning multifunctions
get a target response from function(s) 1–7, but these functions are essentially shadows of function 0. Software that programs
to function(s) 1–7 is re-mapped to function 0.
Note: BIOS programmers should take special care to read bit_7 in PCI Header Type register (Offset 0x0E)
before scanning the BCM5722 Ethernet controller PCI configuration space.
Func
DeviceFunctions:
Single Function = 0
Multi-Function = 1
Header Layout
[0
]
[6][7]