WG82577LM S LGWS Intel, WG82577LM S LGWS Datasheet - Page 42

• Manufacturer Part Number: WG82577LM S LGWS
• Manufacturer: Intel

Specifications of WG82577LM S LGWS

• Lead Free Status / RoHS Status: Supplier Unconfirmed

7.3.2
Note:
Note:
7.4
35
1. The XON frame is also forwarded to the MAC.
Once the 82577 has validated the reception of an XOFF, or PAUSE frame, it does the
following:
Resuming transmission might occur under the following conditions:
Once the 82577 has validated the reception of an XON frame, it does the following:
Transmitting PAUSE Frames
Transmitting PAUSE frames is done as a result of an In-Band Control command from
the MAC. The MAC initiates an in-band message if it is enabled by software by writing a
1b to the TFCE bit in the Device Control register.
Similar to receiving flow control packets previously mentioned, XOFF packets can be
transmitted only if this configuration has been negotiated between the link partners via
the auto-negotiation process. In other words, the setting of this bit indicates the
desired configuration.
When the in-band message from the MAC is received, the 82577 sends a PAUSE frame
with its Pause Timer field equal to FCTTV. Once the receive buffer fullness reaches the
low water mark, the MAC sends an in-band message indicating to send an XON
message (a PAUSE frame with a timer value of zero).
Transmitting flow control frames should only be enabled in full-duplex mode per the
IEEE 802.3 standard. Software should make sure that the transmission of flow control
packets is disabled when the 82577 is operating in half-duplex mode.
Wake Up
The 82577 supports host wake up.
This mechanism uses in-band messages to wake the Intel
from a sleep state. The host can enable host wake up from the 82577 by setting the
Host_WU_Active bit. When this bit is set, after the host transitions to a low power
state, the SMBus interface is still active and the wake up indication from the 82577 to
the Intel
SMBus.
• Initializes the pause timer based on the packet’s Pause Timer field
• Disables packet transmission or schedules the disabling of transmission after the
• Sends an in-band status command with the TX OFF bit set.
• Forward the XOFF or PAUSE frame to the MAC.
• Expiration of the PAUSE timer.
• Reception of an XON frame (a frame with its PAUSE timer set to zero).
• Enables packet transmission.
• Sends an in-band status command with the Tx OFF bit cleared.
• Forwards the XON frame to the MAC.
current packet completes.
®
5 Series Express Chipset would come in as an in-band message over the
82577 GbE PHY—Device Functionality
®
5 Series Express Chipset
1