82540EP — Networking Silicon
14 Datasheet
3.5
3.5.1 Crystal Signals
3.5.2 Analog Signals
Symbol Type Name and Function
XTAL1 I Crystal One. The Crystal One pin is a 25 MHz +/- 50 ppm in put signal. It can be
connected to eithe r an oscillator or crystal. If a cr ystal is used, Cr ystal Two (XTAL2)
must also be conn ected.
XTAL2 O Crystal Two. Crystal Two is the output o f an internal os cillator circuit used to drive a
crystal into osc illation. If an exte rnal oscillator is used in the des ign, XTAL2 must be
disconnected.
Symbol Type Name and Function
REF P Reference. This Reference signal should be connected to VSS through an external
2.49 KΩ resistor.
MDI[0]+/- A
Media Dependent Interface [ 0].
1000BASE-T: In MDI configuration, MDI[0]+/- c orresponds to BI_DA+/-, and in MDI-X
configuration, MDI[0] +/- corresponds to BI_D B +/ - .
100BASE-TX: In MDI configuration, MDI[0]+ /- is used for the transmit pair, and in MDI-X
configuration, MDI[0] +/ - is use d for the receive pair.
10BASE-T: In MDI configuratio n, MDI[0]+/- is used for the transmit pair, and in MDI-X
configuration, MDI[0] +/ - is use d for the receive pair.
MDI[1]+/- A
Media Dependent Interface [ 1].
1000BASE-T: In MDI configuration, MDI[1]+/- c orresponds to BI_DB+/-, and in MDI-X
configuration, MDI[1] +/- corresponds to BI_DA+ /- .
100BASE-TX: In MDI configuration, MDI[1]+ /- is used for the receive pair, and in MDI-X
configuration, MDI[1] +/ - is use d for the t rans it pair.
10BASE-T: In MDI configuration, MDI[1] +/ - is used for the receive pair, and in MDI-X
configuration, MDI[1] +/ - is use d for the t rans it pair.
MDI[2]+/- A
Media Dependent Interface [ 2].
1000BASE-T: In MDI configuration, MDI[2]+/- cor responds to BI_DC+/-, and in MDI-X
configuration, MDI[2] +/- corresponds to BI_D D+ /-.
100BASE-TX: Unused.
10BASE-T: Unused.
MDI[3]+/- A
Media Dependent Interface [ 3].
1000BASE-T: In MDI configuration, MDI[3]+/- cor responds to BI_DD+/-, and in MDI-X
configuration, MDI[3] +/- corresponds to BI_D C+ /-.
100BASE-TX: Unused.
10BASE-T: Unused.