
End of Frame Encoding
R
Note: The first Idle to follow the frame termination sequence will be a /I1/ if the frame ended with positive running disparity or a /I2/ if the frame ended with negative running disparity. This is illustrated as the shaded code group.
gmii_txd[7:0] | FCS |
gmii_tx_en |
|
gmii_tx_er |
|
PCS Transmit Engine Encoding
tx_code_group | FCS | T R R I1/I2 I2 | I2 | I2 |
|
Figure D-7: 1000BASE-X Transmit State Machine Operation (Even Case)
Reception of the Odd Case
Figure D-8 illustrates the reception of the in-bound code-group stream, received either serially using the RocketIO transceiver, or in parallel across the TBI, and translation of this code-group stream into the receiver GMII. This is performed by the PCS Receive Engine.
Note that, as defined in IEEE 802.3 figure
rx_code_group | FCS | T R R I1/I2 I2 | I2 | I2 |
PCS Receive Engine Decoding
gmii_rxd[7:0] | FCS | 0x0F |
gmii_rx_dv
gmii_rx_er
Figure D-8: 1000BASE-X Reception State Machine Operation (Odd Case)
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