Sun Microsystems 220R - Manual (Page 267)

C.1.10.2 External Transceivers
The following external transceivers are connected through the MII port:
4 6211 Micro 100BASE-FX FastEthernet transceiver
4 CT4-1030 100BASE-T4 transceiver
4 CFX-107X 100BASE-FX transceiver
4 XF467A MII-to-AUI transceiver
C.1.10.3 External Cables
The MII port supports an 18 inch (0.5-meter) long, 40-conductor, 20 signal-ground,
STP cable. The single-ended impedance of the cable is 68 ohms (+/-10%). The
propagation delay for each twisted-pair, measured from the MII connector to the
PHY, does not exceed 2.5 nanoseconds.
The RJ45 Ethernet port supports a Category 5, UTP cable for the 100BASE-TX, and a
Category 3, 4, or 5 UTP cable for the 10BASE-T operation.
Note - The maximum cable segment lengths for the 100BASE-TX and 10BASE-TX are
300 feet (100 meters) and 3000 feet (1000 meters), respectively.
C.1.10.4 Connectors
A 40-pin connector is used for the MII connector. A standard 8-pin RJ45 connector
with a shield is used for the AUI connector.
C.1.10.5 MII Power
A regulated 5-VDC (+/- 5%) voltage is supplied to the PHY IC over the load range
of from 0 to 750 mA. A 2-amp overcurrent protection circuit is provided by a
polymer-based resettable fuse to the MII supply voltage.
MII-to-AUI connection to a 10-Mbps medium attachment unit requires a
supplemental power source to meet the AUI power supply requirements. The
MII-AUI converter provides the necessary supplemental power.
C.1.10.6 MII Port Timing
MII port timing encompasses two configurations involving the use of either an
on-board transceiver or external transceivers. For either transceiver configuration, the
MII port timing is the same because MII operates with a 40-nanosecond cycle time.
Functional Description 267