EP80579 Datasheet, PDF (1879/1916 Pages) Intel Corporation – Intel® EP80579 Integrated Processor Product Line

Intel^® EP80579 Integrated Processor
49.5.13
Gigabit Ethernet (GbE: RMII, RGMII, MDIO, EEPROM)
The EP80579 contains three Gigabit Ethernet MACs. The GbE Ethernet MACs contained
in the EP80579 resemble the Intel^® 82545 Gigabit Ethernet Controller.
The EP80579 Gigabit Ethernet (GbE) MAC is based on a fourth generation Gigabit MAC
to provide a standard IEEE 802.3 Ethernet interface for 1000BASE-T, 100BASE-Tx, and
10BASE-T applications. The MAC is capable of transmitting and receiving data rates of
10/100/1000 Mbps. Through the GbE interfaces, the EP80579 can be connected to
Reduced Ethernet (RMII), or Reduced GMII (RGMII) external PHY devices.
The EP80579 can support both 3.3V and 2.5V PHY for the GbE interface. The media
outputs use 2.5V drivers that are 3.3V tolerant. This is a violation of the RMII
specification, which calls for TTL level outputs (not LVTTL) and 5V input level tolerance.
All major PHY devices that may be used in an EP80579 system are expected to drive a
maximum voltage of 3.3V.
RGMII version 1.3 is specified as a 2.5V CMOS level I/O interface and as such, the
EP80579 is fully compliant. RGMII version 2.0 is specified as a 1.5 V HSTL I/O interface
and the EP80579 is NOT compliant with this standard. All PHY devices that are used
with the EP80579 must support version 1.3. The MDIO, MDC, and serial EEPROM bus
are implemented with 2.5V I/O drivers.
Management Data Input/Output (MDIO) interface provides a path to transfer control
information and status between the PHY and the EP80579. The MDIO interface allows
the software to continuously poll the PHY’s configuration registers through and
reprogram the GbE configuration. Management Data Clock (MDC) is sourced by the
EP80579 to the PHY devices as a timing reference for the MDIO interface.
A single four-wire Microwire* interface is provided for connection of an optional,
externally connected serial EEPROM. The serial EEPROM may be used to provide
configuration information to the GbE MACs upon power-up or reset. All three MACs
share the same EEPROM.
This section describes the electrical characteristics of the GbE interface.
49.5.13.1 Gigabit Ethernet Signal List
For Gigabit Ethernet MAC pin description refer to Table 48-22, “Gigabit Ethernet
Interface Signals” on page 1760.
49.5.13.2 Gigabit Ethernet DC Characteristics
49.5.13.2.1 DC Characteristics: RMII and RGMII Mode of Operation
Table 49-66. DC Input Characteristics: RMII Mode of Operation (Sheet 1 of 2)
Symbol
Parameter
Conditions
Min Typical Max
Units
V_IH
Input high voltage
V_IH > V_{IH_Min}
V_CC = Min
2.0
-
3.6
V
V_IL
Input low voltage
V_IH > V_{IL_Max}
V_CC = Min
-
-
0.8
V
I_IH
Input high current
V_CC = Max
V_IN = 2.5 V
-
-
15
uA
Notes
-
-
-
August 2009
Order Number: 320066-003US
Intel^® EP80579 Integrated Processor Product Line Datasheet
1879