Designing with the Client-side GMII for the 1000BASE-X Standard

R

Normal Frame Reception with Extension Field

In accordance with the IEEE 802.3, clause 36, state machines for the 1000BASE-X PCS, gmii_rx_er may be driven high following reception of the end frame in conjunction with gmii_rxd[7:0] containing the hexadecimal value of 0x0F to signal carrier extension. This is illustrated in Figure 5-4. See Appendix D, “1000BASE-X State Machines” for more information.

This is not an error condition and may occur even for full-duplex frames.

gmii_rxd[7:0]preamble

gmii_rx_dv

gmii_rx_er

SFD

FCS 0x0F

Figure 5-4:GMII Normal Frame Reception with Carrier Extension

Frame Reception with Errors

The signal gmii_rx_er when asserted within the assertion window signals that a frame was received with a detected error (Figure 5-5). In addition, a late error may also be detected during the Carrier Extension interval. This is indicated by gmii_rxd[7:0] containing the hexadecimal value 0x1F, also illustrated in Figure 5-5.

gmii_rxd[7:0]preamble

gmii_rx_dv

gmii_rx_er

SFD

FCS 0x0F 0x0F

0x1F

error during frame

error during extension

Figure 5-5:GMII Frame Reception with Errors

Ethernet 1000BASE-X PCS/PMA or SGMII v9.1

www.xilinx.com

55

UG155 March 24, 2008

Page 55
Image 55
Xilinx 1000BASE-X manual Normal Frame Reception with Extension Field, Frame Reception with Errors