WG82574L S LBA9 Intel, WG82574L S LBA9 Datasheet - Page 236

• Manufacturer Part Number: WG82574L S LBA9
• Description: CONTROLLER, ENET, INTEL 82574L, 64PQFN
• Manufacturer: Intel

Specifications of WG82574L S LBA9

• Ethernet Type: IEEE 802.3, IEEE 802.3u, IEEE 802.3ab
• Supply Voltage Range: 3V To 3.6V
• Operating Temperature Range: 0°C To +85°C
• Digital Ic Case Style: QFN
• No. Of Pins: 64
• Package / Case: QFN
• Interface Type: I2C, JTAG, PCI, SPI
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.9.4
8.9.4.1
8.9.5
8.9.6
236
Status Registers
If the NVM image is configured correctly, the physical connections are valid, and
problems still exist, use utilities/drivers to check the appropriate 82574L status
registers for other indications.
Management Control Register (MANC 0x5820)
This register is described in detail in the
This register indicates which filters are enabled. It is possible to configure all of the
filters yet not enable them, in which case, no management traffic is routed to the
MC.Or, the MC might be receiving undesired traffic, such as ARP requests when the
82574L was configured to do automatic ARP responses.
Check this register if getting unwanted traffic or if packets aren’t getting sent to the
MC.
Bit 17 (Receive TCO Packets Enable) must also be set in order for any packets are sent
to a MC. Note that it doesn’t matter what the other enabled filters are, if this one is off,
no packets are sent to the MC.
Bit 21 (Enable Management-to-Host) enables or disables the various filters that also
enable manageability traffic (all those that pass the filters in the 82574L) to optionally
be passed to the operating system.
Unable to Transmit Packets from the MC
If the MC has been transmitting and receiving data without issue for a period of time
and then begins to receive NACKs from the 82574L when it attempts to write a packet,
the problem is most likely due to the fact that the buffers internal to the 82574L are full
of data that has been received from the network; however, has yet to be read by the
MC.
Being an embedded device, the 82574L has limited buffers that it shares for receiving
and transmitting data. If a MC does not keep the incoming data read, the 82574L can
be filled up, which does not enable the MC to transmit anymore data, resulting in
NACKs.
If this situation occurs, the recommended solution is to have the MC issue a Receive
Enable command to disable anymore incoming data, go read all the data from the
82574L and then use the Receive Enable command to enable incoming data once
again.
SMBus Fragment Size
The SMBus specification indicates a maximum SMBus transaction size of 32 bytes. Most
of the data passed between the 82574L and the MC over the SMBus is RMCP/RMCP+
traffic, which by its very nature (UDP traffic) is significantly larger than 32 bytes in
length, thus requiring multiple SMBus transactions to move a packet from the 82574L
to the MC or to send a packet from the MC to the 82574L.
Recognizing this bottleneck, the 82574L can handle up to 240 bytes of data within a
single transaction. This is a configurable setting within the NVM.
The default value in the NVM images is 32, per the SMBus specification. If performance
is an issue, it is recommended that you increase this size.
section
82574 GbE Controller—System Manageability
10.0.