LAN9221_12 Datasheet, PDF (19/151 Pages) SMSC Corporation – High-Performance 16-bit Non-PCI 10/100 Ethernet Controller with Variable Voltage I/O

High-Performance 16-bit Non-PCI 10/100 Ethernet Controller with Variable Voltage I/O
Datasheet
NAME
Auto-MDIX Enable
Table 2.4 System and Power Signals (continued)
SYMBOL
AMDIX_EN
BUFFER
TYPE
VIS
(PU)
NUM
PINS
1
DESCRIPTION
Enables Auto-MDIX. Pull high or leave
unconnected to enable Auto-MDIX, pull low to
disable Auto-MDIX.
Note:
When operating at reduced
VDDVARIO voltage levels (less than
3.0V), this pin must be pulled to a valid
level with an external resistor. Refer to
Section 2.2, "External Pull-Up/Pull-
Down Resistors" for more information.
Test
TEST
General Purpose
I/O data,
nLED1 (Speed
Indicator),
nLED2 (Link &
Activity Indicator),
nLED3 (Full-
Duplex
Indicator).
GPIO[2:0]/
nLED[3:1]
Variable Voltage
I/O Power
VDDVARIO
Common Ground
+3.3V Regulator
Power Supply
VSS
VDD33REG
SMSC LAN9221/LAN9221i
VIS
(PD)
VIS/
VO12/
VOD12
P
P
P
1
3
4
1 pad
1
Reserved for internal test purposes only.
Note:
When operating at a reduced
VDDVARIO voltage (less than 3.0V),
this pin must be connected to ground
or pulled-low with an external resistor.
When VDDVARIO = 3.3V, this pin may
be left unconnected. Refer to Section
2.2, "External Pull-Up/Pull-Down
Resistors" for more information.
General Purpose I/O data: These three
general-purpose signals are fully programmable
as either push-pull output, open-drain output or
input by writing the GPIO_CFG configuration
register in the CSR’s. They are also multiplexed
as GP LED connections.
GPIO signals are Schmitt-triggered inputs.
When configured as LED outputs these signals
are open-drain.
nLED1 (Speed Indicator). This signal is driven
low when the operating speed is 100Mb. During
auto-negotiation, when the cable is
disconnected, and during 10Mbs operation, this
signal is driven high.
nLED2 (Link & Activity Indicator). This signal
is driven low (LED on) when the
LAN9221/LAN9221i detects a valid link. This
signal is pulsed high (LED off) for 80mS
whenever transmit or receive activity is
detected. This signal is then driven low again
for a minimum of 80mS, after which time it will
repeat the process if TX or RX activity is
detected. Effectively, LED2 is activated solid for
a link. When transmit or receive activity is
sensed LED2 will flash as an activity indicator.
nLED3 (Full-Duplex Indicator). This signal is
driven low when the link is operating in full-
duplex mode.
Variable Voltage I/O logic power supply pins.
Refer to Section 7.2, "Operating Conditions**,"
on page 139 for additional details.
Common Ground
+3.3V power supply for internal +1.8V regulator.
19
DATASHEET
Revision 2.9 (03-01-12)