Data Sheet

Interconnects—Ethernet Controller I210

3.1.4.1 Transaction Types Accepted by the I210

Flow control types:

• PH - Posted request headers

• PD - Posted request data payload

• NPH - Non-posted request headers

• NPD - Non-posted request data payload

•CPLH - Completion headers

• CPLD - Completion data payload

3.1.4.1.1 Configuration Request Retry Status

PCIe supports devices requiring a lengthy self-initialization sequence to complete before they are able

to service configuration requests. This is the case for the I210 where initialization is long due to the

Flash read operation following reset.

If the read of the PCIe section in the Flash was not completed and the I210 receives a configuration

request, the I210 responds with a configuration request retry completion status to terminate the

request. This effectively stalls the configuration request until the subsystem completes a local

initialization and is ready to communicate with the host.

3.1.4.1.2 Partial Memory Read and Write Requests

The I210 has limited support of read and write requests when only part of the byte enable bits are set

as described later in this section.

Partial writes to the MSI-X table are supported. All other partial writes are ignored and silently dropped.

Zero-length writes have no internal impact (nothing written, no effect such as clear-by-write). The

transaction is treated as a successful operation (no error event).

Partial reads with at least one byte enabled are answered as a full read. Any side effect of the full read

(such as clear by read) is applicable to partial reads also.

Zero-length reads generate a completion, but the register is not accessed and undefined data is

returned.

Table 3-4. Transaction Types Accepted by the Transaction Layer

Transaction Type FC Type

Tx Later

Reaction

Hardware Should Keep Data

From Original Packet

Configuration Read Request NPH CPLH + CPLD Requester ID, TAG, Attribute

Configuration Write Request NPH + NPD CPLH Requester ID, TAG, Attribute

Memory Read Request NPH CPLH + CPLD Requester ID, TAG, Attribute

Memory Write Request PH + PD - -

I/O Read Request NPH CPLH + CPLD Requester ID, TAG, Attribute

I/O Write Request NPH + NPD CPLH Requester ID, TAG, Attribute

Read Completions CPLH + CPLD - -

Message PH+ PD

1. MCTP messages contains a payload.