Xilinx Virtex-4 - Page 53

Embedded Tri-Mode Ethernet MAC User Guide www.xilinx.com 53
UG074 (v2.2) February 22, 2010
Client Interface
R
Frame Reception with Errors
An unsuccessful frame reception (for example, a fragment frame or a frame with an
incorrect FCS) is shown in Figure 3-18. In this case, the EMAC#CLIENTRXBADFRAME
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.
Figure 3-19 shows the timing of an unsuccessful frame reception in SGMII and
1000BASE-X PCS/PMA modes.
The following conditions cause the assertion of EMAC#CLIENTRXBADFRAME:
• Standard Conditions:
• FCS errors occur.
• Packets are shorter than 64 bytes (undersize or fragment frames).
Figure 3-18: Frame Reception with Error
DA SADATAL/T
ug074_3_20_080805
EMAC#CLIENTRXD[7:0]
EMAC#CLIENTRXGOODFRAME
EMAC#CLIENTRXBADFRAME
CLIENTEMAC#RXCLIENTCLKIN
EMAC#CLIENTRXDVLD
Figure 3-19: Unsuccessful Frame Reception (SGMII and 1000BASE-X PCS/PMA Modes)
CLIENTEMAC#RXCLIENTCLKIN
FCS
/T/ /R/ /l1/
PHYEMAC#RXCHARISCOMMA
PHYEMAC#RXCHARISK
PHYEMAC#RXD[7:0]
EMAC#CLIENTRXDVLD
EMAC#CLIENTRXGOODFRAME
EMAC#CLIENTRXBADFRAME
UG074_3_21_081805
PRE DA SA Data FCS
EMAC#CLIENTRXD[7:0]
/V/
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