SMSC LAN9420i Manual De Usuario

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Single-Chip Ethernet Controller with HP Auto-MDIX Support and PCI Interface
Datasheet
SMSC LAN9420/LAN9420i
19
Revision 1.22 (09-25-08)
DATASHEET
Table 2.5 PLL and Ethernet PHY Pins
NUM
PINS
NAME
SYMBOL
BUFFER
TYPE
DESCRIPTION
1
Crystal Input
XI
ICLK
Crystal Input: External 25MHz crystal input. This pin 
can also be driven by a single-ended clock oscillator. 
When this method is used, XO should be left 
unconnected.
1
Crystal 
Output
XO
OCLK
Crystal Output: External 25MHz crystal output.
1
Ethernet TX 
Data Out 
Negative
TPO-
AIO
Ethernet Transmit Data Out Negative: The transmit 
data outputs may be swapped internally with receive 
data inputs when Auto-MDIX is enabled. 
1
Ethernet TX 
Data Out 
Positive
TPO+
AIO
Ethernet Transmit Data Out Positive: The transmit 
data outputs may be swapped internally with receive 
data inputs when Auto-MDIX is enabled. 
1
Ethernet RX 
Data In 
Negative
TPI-
AIO
Ethernet Receive Data In Negative: The receive data 
inputs may be swapped internally with transmit data 
outputs when Auto-MDIX is enabled. 
1
Ethernet RX 
Data In 
Positive
TPI+
AIO
Ethernet Receive Data In Positive: The receive data 
inputs may be swapped internally with transmit data 
outputs when Auto-MDIX is enabled. 
1
External 
PHY Bias 
Resistor
EXRES
AI
External PHY Bias Resistor: Used for the internal 
PHY bias circuits. Connect to an external 12.4K 1.0% 
resistor to ground.