Data Sheet

Interconnects—Ethernet Controller I210
41
The PCIe specification does not ensure that completions for separate requests return in-order. Read
completions for concurrent requests are not required to return in the order issued. The I210 handles
completions that arrive in any order. Once all completions arrive for a given request, the I210 might
issue the next pending read data request.
• The I210 incorporates a re-order buffer to support re-ordering of completions for all requests. Each
request/completion can be up to 2 KB long. The maximum size of a read request is defined as the
minimum {2 KB, Max_Read_Request_Size}.
In addition to the 6 pipeline requests for transmit data, the I210 can issue up to one read request to
fetch transmit descriptors and one read requests to fetch receive descriptors. The requests for transmit
data, transmit descriptors, and receive descriptors are independently issued. Each descriptor read
request can fetch up to 16 descriptors for reception and 24 descriptors for transmission.
3.1.4.3 Messages
3.1.4.3.1 Message Handling by the I210 (as a Receiver)
Message packets are special packets that carry a message code.
The upstream device transmits special messages to the I210 by using this mechanism.
The transaction layer decodes the message code and responds to the message accordingly.
Table 3-6. Supported Message in the I210 (as a Receiver)
Message
Code [7:0]
Routing r2r1r0 Message I210 Response
0x00 011b Unlock Silently drop
0x14 100b PM_Active_State_NAK Accepted
0x19 011b PME_Turn_Off Accepted
0x40
0x41
0x43
0x44
0x45
0x47
0x48
100b Ignored messages (used to be hot-plug messages) Silently drop
0x50 100b Slot power limit support (has one Dword data) Silently drop
0x7E
000b
010b
011b
100b
Vendor_defined type 0
Drop and handle as an
Unsupported Request
0x7F 100b Vendor_defined type 1 Silently drop
0x7F
000b
010b
011b
Vendor_defined type 1
(see Section 3.1.4.3.3)
Send to MCTP reassembly if
Vendor ID = 0x1AB4 (DMTF) and
VDM code - 0000b (MCTP).
Otherwise, silently drop