Signal Descriptions
MCF52235 ColdFire® Integrated Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor
2-11
2.8
Fast Ethernet Controller PHY Signals
describes the Fast Ethernet Controller (FEC) Signals.
2.9
I
2
C I/O Signals
describes the I
2
C serial interface module signals.
Table 7. Fast Ethernet Controller (FEC) Signals
Signal Name
Abbreviation
Function
I/O
Twisted Pair Input +
RXP
Differential Ethernet twisted-pair input pin. This pin is high-impedance
out of reset.
I
Twisted Pair Input -
RXN
Differential Ethernet twisted-pair input pin. This pin is high-impedance
out of reset.
I
Twisted Pair
TXN
Differential Ethernet twisted-pair output pin. This pin is
high-impedance out of reset.
O
Twisted Pair Output -
TXP
Differential Ethernet twisted-pair output pin. This pin is
high-impedance out of reset.
O
Bias Control Resistor
RBIAS
Connect a 12.4 k
Ω
(1.0%) external resistor, RBIAS, between the
PHY_RBIAS pin and analog ground.
Place this resistor as near to the chip pin as possible. Stray
capacitance must be kept to less than 10 pF
(>50 pF causes instability). No high-speed signals can be permitted in
the region of RBIAS.
I
Activity LED
ACT_LED
Indicates when the EPHY is transmitting or receiving
O
Link LED
LINK_LED
Indicates when the EPHY has a valid link
O
Speed LED
SPD_LED
Indicates the speed of the EPHY connection
O
Duplex LED
DUPLED
Indicates the duplex (full or half) of the EPHY connection
O
Collision LED
COLLED
Indicates if the EPHY detects a collision
O
Transmit LED
TXLED
Indicates if the EPHY is transmitting
O
Receive LED
RXLED
Indicates if the EPHY is receiving
O
Table 2-8. I
2
C I/O Signals
Signal Name
Abbreviation
Function
I/O
Serial Clock
SCL
Open-drain clock signal for the for the I
2
C interface. It is driven by the
I
2
C module when the bus is in master mode or it becomes the clock
input when the I
2
C is in slave mode.
I/O
Serial Data
SDA
Open-drain signal that serves as the data input/output for the I
2
C
interface.
I/O
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
are
not
available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:MCF52234CVM60,
MCF52235CVM60
