Xilinx Virtex-4 User Manual page 55

R
CLIENTEMAC#RXCLIENTCLKIN
EMAC#CLIENTRXD[7:0]
EMAC#CLIENTRXDVLD
EMAC#CLIENTRXGOODFRAME
EMAC#CLIENTRXBADFRAME
VLAN Tagged Frames
The reception of a VLAN tagged frame (if enabled) is shown in
frame is passed to the client to identify the frame as VLAN tagged. This is followed by the
tag control information bytes, V1 and V2. More information on the interpretation of these
bytes is described in the IEEE Std 802.3-2002 standard.
CLIENTEMAC#RXCLIENTCLKIN
EMAC#CLIENTRXD[7:0]
EMAC#CLIENTRXDVLD
EMAC#CLIENTRXGOODFRAME
EMAC#CLIENTRXBADFRAME
Maximum Permitted Frame Length/ Jumbo Frames
The maximum length of a frame specified in the IEEE Std 802.3-2002 standard is 1518 bytes
for non-VLAN tagged frames. VLAN tagged frames can be extended to 1522 bytes. When
jumbo frame handling is disabled and the Ethernet MAC receives a frame exceeding the
maximum legal length, EMAC#CLIENTRXBADFRAME is asserted. When jumbo frame
handling is enabled, frames longer than the legal maximum are received in the same way
as shorter frames.
For more information on enabling and disabling jumbo frame handling, see
"Configuration Registers," page
www.BDTIC.com/XILINX
Embedded Tri-Mode Ethernet MAC User Guide
UG074 (v2.2) February 22, 2010
DA
Figure 3-20: Frame Reception with In-Band FCS Field
DA
Figure 3-21: Reception of a VLAN Tagged Frame
www.xilinx.com
SA L/T
81 00 V1 V2
SA VLAN
Tag
74.
Client Interface
DATA FCS
ug074_3_22_080805
Figure 3-21. The VLAN
L/T DATA
ug074_3_23_080805
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