Maxim Integrated DS33R11 - Manual (Page 61)

DS33R11 Ethernet Mapper with Integrated T1/E1/J1 Transceiver
61 of 344
9.15.1 MII Mode Options
The Ethernet interface can be configured for MII operation by setting the hardware pin RMIIMIIS low. The MII
interface consists of 17 pins. For instructions on clocking the Ethernet Interface while in MII mode, see Section
9.1 .
Diagrams of system connections for MII operation are shown in Figure 9-5 and Figure 9-6 .
9.15.2 RMII Mode
The Ethernet interface can be configured for RMII operation by setting the hardware pin RMIIMIIS high. RMII
interface operates synchronously from the external 50MHz reference (REF_CLK). Only seven signals are required.
The following figure shows the RMII architecture. Note that DCE mode is not supported for RMII mode and RMII is
valid only for full duplex operation.
Figure 9-7. RMII Interface
TXD[1:0]
TX_EN
REF_CLK
RXD[1:0]
CRS_DV
DS33R11 MAC External PHY