EP80579 Datasheet, PDF (1762/1916 Pages) Intel Corporation – Intel® EP80579 Integrated Processor Product Line

Intel^® EP80579 Integrated Processor
Table 48-22. Gigabit Ethernet Interface Signals (Sheet 3 of 4)
Signal Name
GBE_REFCLK
IO Type
Direction
Ball
Count
2.5VCMOS I
1
External
Pull-Up/
Down
[Ohms]
BSC/
XOR
Signal Description Normal/Alternate
Mode
BSC
Gigabit Ethernet Controller Reference Clock:
50MHz or 125MHz (depend on mode)
reference clock for the GbE Controller.
In RGMII mode or mixed mode (RGMII and
RMII), the frequency of this clock must be
125MHz regardless of the individual port
transmit and receive rates and this clock must
always be present.
In RMII mode (all ports only), there are two
clocks required. The GBE_REFCLK_RMII is
required as per the RMII spec. The
GBE_REFCLK is also required for the RCOMP
controller and the retrieval of the port
information from the EEPROM. In RMII mode
(all ports only), the GBE_REFCLK can be either
50Mhz or 125Mhz. If both clock are the same
frequency, connecting GBE_REFCLK and
GBE_REFCLK_RMII to the same source will
work fine.
GBE_REFCLK_RMII 2.5VCMOS I
GBE_RCOMPP
Analog
I/O
GBE_RCOMPN
Analog
I/O
EEDI
2.5VCMOS O
Gigabit Ethernet Controller RMII Reference
Clock: 50Mhz reference clock for the GbE
1
BSC
Controller in RMII Mode. The frequency of this
clock is 50MHz regardless of the individual port
transmit / receive rates and must always be
present.
1
50 Down
(to VSS)
Gigabit Ethernet Controller Compensation: Off-
die reference resistor to which the output
driver pull up output impedance is matched
(nominally 50 ohms to ground).
1
50 Up (to
VCCSUS25)
Gigabit Ethernet Controller Compensation: Off-
die reference resistor to which the output
driver pull down output impedance is matched
(nominally 50 ohms to VCCSUS25).
Gigabit Ethernet Controller EEPROM Input
Data: LVTTL data output to serial EEPROM.
This pin is also sampled at an edge of
GBE_AUX_PWR_GOOD to indicate the
presence of the auxiliary power supply for
10K Up (if
GbE0.
1
AUX_PWR_
PRESENT),
otherwise
4.7K Down
BSC
Gigabit Ethernet Controller aux_pwr Strap:
This strap indicates if an auxiliary supply is
being used for GbE0.
The EP80579 interprets the strap as follows:
0 = No aux_pwr mode (i.e., auxiliary supply
is not used).
1 = aux_pwr mode support (i.e., auxiliary
supply is used)
EEDO
EECS
EESK
2.5VCMOS I
1
2.5VCMOS O
1
2.5VCMOS O
1
BSC
BSC
BSC
Gigabit Ethernet Controller EEPROM Output
Data.
Gigabit Ethernet Controller EEPROM Chip
Select: chip select to enable the EEPROM
device.
Gigabit Ethernet Controller EEPROM Shift
Clock: clock for the EEPROM interface,
frequency is ~1MHz.
Intel^® EP80579 Integrated Processor Product Line Datasheet
1762
August 2009
Order Number: 320066-003US