Micrel, Inc.
KSZ8041NL/RNL
Pin Description – KSZ8041NL
Type(1)
Pin Number Pin Name
Pin Function
1
2
3
4
5
6
7
8
GND
Gnd
P
Ground
VDDPLL_1.8
VDDA_3.3
RX-
1.8V analog VDD
P
3.3V analog VDD
I/O
I/O
I/O
I/O
O
Physical receive or transmit signal (- differential)
Physical receive or transmit signal (+ differential)
Physical transmit or receive signal (- differential)
Physical transmit or receive signal (+ differential)
Crystal feedback
RX+
TX-
TX+
XO
This pin is used only in MII mode when a 25 MHz crystal is used.
This pin is a no connect if oscillator or external clock source is used, or if RMII mode
is selected.
9
XI /
I
Crystal / Oscillator / External Clock Input
REFCLK
MII Mode:
25MHz +/-50ppm (crystal, oscillator, or external clock)
50MHz +/-50ppm (oscillator, or external clock only)
RMII Mode:
10
REXT
I/O
Set physical transmit output current
Connect a 6.49KΩ resistor in parallel with a 100pF capacitor to ground on this pin.
See KSZ8041NL reference schematics.
11
12
13
MDIO
MDC
I/O
I
Management Interface (MII) Data I/O
This pin requires an external 4.7KΩ pull-up resistor.
Management Interface (MII) Clock Input
This pin is synchronous to the MDIO data interface.
MII Mode:
Receive Data Output[3](2)
/
RXD3 /
Ipu/O
PHYAD0
Config Mode:
The pull-up/pull-down value is latched as PHYADDR[0] during
power-up / reset. See “Strapping Options” section for details.
14
15
RXD2 /
Ipd/O
Ipd/O
MII Mode:
Receive Data Output[2](2)
/
PHYAD1
Config Mode:
The pull-up/pull-down value is latched as PHYADDR[1] during
power-up / reset. See “Strapping Options” section for details.
RXD1 /
MII Mode:
Receive Data Output[1](2)
Receive Data Output[1](3)
/
/
RXD[1] /
PHYAD2
RMII Mode:
Config Mode:
The pull-up/pull-down value is latched as PHYADDR[2] during
power-up / reset. See “Strapping Options” section for details.
16
RXD0 /
Ipu/O
MII Mode:
Receive Data Output[0](2)
Receive Data Output[0](3)
/
/
RXD[0] /
DUPLEX
RMII Mode:
Config Mode:
Latched as DUPLEX (register 0h, bit 8) during power-up /
reset. See “Strapping Options” section for details.
17
18
VDDIO_3.3
RXDV /
P
3.3V digital VDD
MII Mode:
Ipd/O
Receive Data Valid Output /
CRSDV /
CONFIG2
RMII Mode:
Config Mode:
Carrier Sense/Receive Data Valid Output /
The pull-up/pull-down value is latched as CONFIG2 during
power-up / reset. See “Strapping Options” section for details.
19
RXC
O
MII Mode:
Receive Clock Output
September 2010
10
M9999-090910-1.4
MICREL [ MICREL SEMICONDUCTOR ]
