WG82574IT S LBAC Intel, WG82574IT S LBAC Datasheet - Page 176

• Manufacturer Part Number: WG82574IT S LBAC
• Description: CONTROLLER, ENET, INTEL 82574IT, 64PQFN
• Manufacturer: Intel

Specifications of WG82574IT S LBAC

• Ethernet Type: IEEE 802.3, IEEE 802.3u, IEEE 802.3ab
• Supply Voltage Range: 3V To 3.6V
• Operating Temperature Range: -40°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

7.3.4
7.3.5
176
TCP Segmentation Source Data
Once the TCP segmentation context has been set, the next descriptor (data descriptor)
provides the initial data to transfer. This first data descriptor must point to data
containing an Ethernet header of the type indicated. The 82574L fetches the prototype
(partial pseudo-header) header from the host data buffer into an internal buffer and
this header is prepended to every packet for this TSO operation. The prototype (partial
pseudo-header) header is modified accordingly for each MSS sized segment. The
following sections describe the supported packet types and the various updates that
are performed by hardware. This should be used as a guide to determine what must be
modified in the original packet header to make it a suitable prototype (partial pseudo-
header) header.
The following summarizes the fields considered by the driver for modification in
constructing the prototype (partial pseudo-header) header.
MAC Header (for SNAP)
IPv4 Header
IPv6 Header
TCP Header
UDP Header
The 82574L's DMA function fetches the IP, and TCP/UDP prototype (partial pseudo-
header) header information from the initial descriptor(s) and save them on-chip for
individual packet header generation.
Hardware Performed Updating for Each Frame
The following sections describe the updating process performed by the hardware for
each frame sent using the TCP segmentation capability.
• MAC Header LEN field should be set to 0b.
• Length should be set to zero.
• Identification field should be set as appropriate for first packet of send (if not
• Header checksum should be zeroed out unless some adjustment is needed by the
• Length should be set to zero.
• Sequence number should be set as appropriate for first packet of send (if not
• PSH, and FIN flags should be set as appropriate for LAST packet of send.
• TCP checksum should be set to the partial pseudo-header checksum.
• UDP checksum should be set to the partial pseudo-header checksum.
already).
software device driver.
already).
82574 GbE Controller—Inline Functions