EP80579 Datasheet, PDF (1887/1916 Pages) Intel Corporation – Intel® EP80579 Integrated Processor Product Line

Intel^® EP80579 Integrated Processor
49.5.13.3.7 GbE Ethernet Interface — RMII Mode
This section describes the AC timings for GbE interface when the interconnect is
designed for a RMII interface.
In RMII mode of operation, both transmit and receive (TX_DATA and RX_DATA) are
with respect to external clock, which in 10/100 Base T is 50 MHz.
Figure 49-38 shows the GbE signal connections used in RMII mode for 10/100 Base
connections. An external clock is sourcing the reference clock.
Figure 49-38.GbE RMII Mode Signal Connection Block Diagram — External Clock Source
RMII Signals
GbEn MAC
GBEn_ TxCTL
GBEn_ TxData[3]
GBEn_ TxData[1:0]
10/100 Base PHY
TX_EN
TX_ER
TXD[1:0]
GBEn_RxCTL
GBEn_RxData[3]
GBEn_RxData[1:0]
GBE
I/O Vcc GBE_REFCLK_RMII
50 MHz
source clock
Vcc
2.5V ± 5%
CRS_DV
RX_ER
RXD[1:0]
REF_CLK
GBE
I/O Vcc
B6576-01
Figure 49-39 shows the timing diagram for RMII mode of operation.
Figure 49-39.GbE RMII Transmit and Receive Waveforms — RMII Mode
20ns
T_SU
T_hold
GBE_REFCLK_RMII
GBEn_RxCTL
GBEn_RxDATA[3:0]
DATA
DATA
B6577-01
Table 49-79 shows the transmit and receive timing values for RMII 100/10 base mode
of operation.
August 2009
Order Number: 320066-003US
Intel^® EP80579 Integrated Processor Product Line Datasheet
1887