LAN9220 Datasheet, PDF (19/150 Pages) SMSC Corporation – 16-bit Non-PCI Small Form Factor 10/100 Ethernet Controller with Variable Voltage I/O & HP Auto-MDIX Support

16-bit Non-PCI Small Form Factor 10/100 Ethernet Controller with Variable Voltage I/O & HP Auto-MDIX Support
Datasheet
Table 2.4 System and Power Signals (continued)
NAME
Test
General Purpose
I/O data,
nLED1 (Speed
Indicator),
nLED2 (Link &
Activity Indicator),
nLED3 (Full-
Duplex
Indicator).
Variable Voltage
I/O Power
Common Ground
+3.3V Regulator
Power Supply
+3.3V Analog
Power
+1.8V Analog
Power
Core Voltage
Decoupling
SYMBOL
TEST
GPIO[2:0]/
nLED[3:1]
VDDVARIO
VSS
VDD33REG
BUFFER
TYPE
VIS
(PD)
VIS/
VO12/
VOD12
P
P
P
NUM
PINS
1
3
4
1 pad
1
DESCRIPTION
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 100Mbs,
during auto-negotiation and when the cable is
disconnected. This signal is driven high only
during 10Mbs operation.
nLED2 (Link & Activity Indicator). This signal
is driven low (LED on) when the LAN9220
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 138 for additional details.
Common Ground
+3.3V power supply for internal +1.8V regulator.
VDD33A
P
3
+3.3V analog power supply pins.
VDD18A
P
VDD18CORE
P
1
+1.8V analog power supply pin. This pin must
be connected externally to VDD18CORE.
2
+1.8 V from internal core regulator. Both pins
must be connected together externally. Each
pin requires a 0.01uF decoupling capacitor. In
addition, pin 2 requires a bulk 4.7uF capacitor
(<2 Ohm ESR) in parallel. These pins must not
be used to supply power to other external
devices.
SMSC LAN9220
19
DATASHEET
Revision 2.6 (12-04-08)