Cirrus Logic CS8952 - Manual (Page 76)

CS8952
CrystalLAN™ 100BASE-X and 10BASE-T Transceiver 76
DS206F1
REPEATER - REPEATER Mode Select. Input, Pin 16.
This pin controls the operation of the CRS (Carrier Sense) pin as shown below:
At power-up or at reset, the value on this pin is latched into bit 12 of the PCS Sub-Layer Configuration
Register (address 17h). This pin includes a weak internal pull-down (> 20 k
Ω), or the value may be set
by an external 4.7 k Ω pull-up or pull-down resistor.
SPD10 - 10 Mb/s Speed Indication. Output, Pin 68.
This pin is asserted high when the CS8952 is configured for 10 Mb/s operation. This pin can be used to
drive a low-current LED to indicate 10 Mb/s operation.
SPD100 - 100 Mb/s Speed Indication. Output, Pin 67.
This pin is asserted high when the CS8952 is configured for 100 Mb/s operation. This pin can be used
to drive a low-current LED to indicate 100 Mb/s operation.
TCM - Transmit Clock Mode Initialization. Input, Pin 59.
The logic value on this three-level pin during power-up or reset determines whether TX_CLK is used as
an input or an output, and whether an external 25 MHz clock reference is provided on the CLK25 output
pin.
TEST[1:0] - Factory Test. Input, Pins 24 and 25.
These pins are for factory test only. They include weak internal pull-downs (> 20 k Ω), and should be tied
directly to VSS for normal operation.
REPEATER pin DUPLEX mode CRS Indicates
high don’t care receive activity only
low full duplex receive activity only
low half duplex receive or transmit activity
TCM pin TX_CLK mode CLK25 status
high TX_CLK is input CLK25 pin is an output
floating TX_CLK is input CLK25 is disabled
low TX_CLK is output CLK25 is disabled