Xilinx Virtex-4 User Manual page 53

R
Frame Reception with Errors
An unsuccessful frame reception (for example, a fragment frame or a frame with an
incorrect FCS) is shown in
signal is asserted to the client at the end of the frame. The client is responsible for dropping
the data already transferred for this frame.
CLIENTEMAC#RXCLIENTCLKIN
EMAC#CLIENTRXD[7:0]
EMAC#CLIENTRXDVLD
EMAC#CLIENTRXGOODFRAME
EMAC#CLIENTRXBADFRAME
Figure 3-19
1000BASE-X PCS/PMA modes.
CLIENTEMAC#RXCLIENTCLKIN
PHYEMAC#RXCHARISCOMMA
PHYEMAC#RXCHARISK
PHYEMAC#RXD[7:0]
EMAC#CLIENTRXD[7:0]
EMAC#CLIENTRXDVLD
EMAC#CLIENTRXGOODFRAME
EMAC#CLIENTRXBADFRAME
Figure 3-19: Unsuccessful Frame Reception (SGMII and 1000BASE-X PCS/PMA Modes)
The following conditions cause the assertion of EMAC#CLIENTRXBADFRAME:
•
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Embedded Tri-Mode Ethernet MAC User Guide
UG074 (v2.2) February 22, 2010
Figure
DA
Figure 3-18: Frame Reception with Error
shows the timing of an unsuccessful frame reception in SGMII and
PRE DA
Standard Conditions:
• FCS errors occur.
• Packets are shorter than 64 bytes (undersize or fragment frames).
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3-18. In this case, the EMAC#CLIENTRXBADFRAME
SA L/T
FCS
/V/
SA
Client Interface
DATA
ug074_3_20_080805
/T/ /R/ /l1/
Data FCS
UG074_3_21_081805
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