lan8720 Standard Microsystems Corp., lan8720 Datasheet - Page 16

• Manufacturer Part Number: lan8720
• Description: Small Footprint Rmii 10/100 Ethernet Transceiver With Hp Auto-mdix Support
• Manufacturer: Standard Microsystems Corp.

Revision 1.0 (04-15-09)
3.3
3.4
REFCLKO
nINTSEL
SIGNAL
SIGNAL
SIGNAL
XTAL1/
XTAL2
NAME
NAME
NAME
CLKIN
LED2/
MDIO
nRST
nINT/
MDC
Management Signals
General Signals
24-QFN
24-QFN
24-QFN
PIN #
PIN #
PIN #
12
13
14
15
2
5
4
TYPE
TYPE
TYPE
IOPU
IOPU
IOPU
IOD8
ICLK
OCL
I8
K
Table 3.3 LED Signals 24-QFN (continued)
Table 3.4 Management Signals 24-QFN
LED2 – Link speed LED Indication.
See
nINTSEL: On power-up or external reset, the mode of the nINT/REFCLKO
pin is selected.
See
Management Data Input/OUTPUT: Serial management data input/output.
Management Clock: Serial management clock.
nINT – Active low interrupt output. Place an external resistor pull-up to
VDDIO.
REFCLKO – 50MHz clock derived from the 25MHz crystal oscillator.
See
Clock Input: Crystal connection or external clock input.
Clock Output: Crystal connection.
External Reset: Input of the system reset. This signal is active LOW.
Table 3.5 General Signals 24-QFN
When LED2/nINTSEL is floated or pulled to VDD2A, nINT is selected for
operation on pin nINT/REFCLKO (default).
When LED2/nINTSEL is pulled low to VSS through a resistor, REFCLKO is
selected for operation on pin nINT/REFCLKO.
See DESCRIPTION of pin 2:
This signal is mux’d with REFCLKO.
Float this pin when an external clock is driven to XTAL1/CLKIN.
Section 5.3.7
Section 4.10
Section 4.7.2
DATASHEET
for additional detail.
for a description of LED modes.
for additional detail.
16
Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support
DESCRIPTION
DESCRIPTION
DESCRIPTION
LED2 – Link speed LED Indication.
SMSC LAN8720/LAN8720i
Datasheet