Xilinx LOGICORE UG144 - Manual (Page 51)

1-Gigabit Ethernet MAC v8.5 User Guide www.xilinx.com 51
UG144 April 24, 2009
Transmitting Outbound Frames R
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Table 5-4: Bit Definition for the Transmitter Statistics Vector
tx_statistics_vector
bit(s) Name Description
31 Pause Frame Asserted if the previous frame was a pause
frame that the MAC itself initiated in
response to a pause_req assertion.
30 Byte Valid Asserted if a MAC frame byte (DA to FCS
inclusive) is in the process of being
transmitted. This is valid on every clock
cycle.
Do not use this as an enable signal to
indicate that data is present on gmii_txd.
29:20 Reserved Always at logic 0.
19 VLAN Frame Asserted if the previous frame contained a
VLAN identifier in the length/type field
when transmitter VLAN operation is
enabled.
18:5 Frame Length The length of the previous frame in number
of bytes. The count will stick at 16,383 for
any jumbo frames larger than this value.
4 Control Frame Asserted if the previous frame had the
special MAC Control Type code 88-08 in the
length/type field.
3 Underrun Frame Asserted if the previous frame contained an
underrun error.
2 Multicast Frame Asserted if the previous frame contained a
multicast address in the destination address
field.
1 Broadcast Frame Asserted if the previous frame contained a
broadcast address in the destination address
field.
0 Successful Frame Asserted if the previous frame was
transmitted without error.