Data Sheet

Ethernet Controller I210 —Interconnects
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required the software or manageability should access the Flash one word at a time releasing
the interface after each word. Software and firmware should avoid holding the Flash bit-bang
interface for more than 500 ms.
The deadlock timeout mechanism is enabled by the Deadlock Timeout Enable bit in the Control Word 1
in the Flash.
3.3.8 VPD Support
The Flash can contain an area for VPD. This area is managed by the OEM vendor and does not influence
the behavior of hardware. Word 0x2F of the Flash contains a pointer to the VPD area in the Flash. It is
recommended to map the VPD area into the RO area of the shadow RAM. Word 0x0A contains the Flash
VPD_EN bit, which controls whether or not the VPD capability appears in the configuration space
following the next PCI reset event. The VPD_EN bit must be set to 1b only once a valid VPD structure is
programmed in the Flash.
The maximum area size is 1024 bytes but can be smaller. The VPD block is built from a list of resources.
A resource can be either large or small. The structure of these resources are listed in the following
tables.
The I210 firmware parses the VPD structure during the auto-load process following PCIe reset in order
to detect the read only and read/write area boundaries. The I210 assumes the following VPD fields with
the limitations listed:
VPD structure limitations:
• The structure must start with a Tag = 0x82.
• The structure must end with a Tag = 0x78. The tag must be word aligned.
Table 3.15. Small Resource Structure
Offset 0 1 — n
Content
Tag = 0xxx,xyyyb (Type = Small(0), Item Name = xxxx, length = yy
bytes)
Data
Table 3.16. Large Resource Structure
Offset 0 1 — 2 3 — n
Content Tag = 1xxx,xxxxb (Type = Large(1), Item Name = xxxxxxxx) Length Data
Table 3.17. VPD Structure
Tag
Length
(bytes)
Data Resource description
0x82
Length of
identifier string
Identifier Identifier string.
0x90
Length of RO
area
RO data VPD-R list containing one or more VPD keywords.
0x91
Length of RW
area
RW data VPD-W list containing one or more VPD keywords. This part is optional.
0x78 n/a n/a End tag.