ICS1894-40 Datasheet, PDF (14/52 Pages) Integrated Device Technology – 10BASE-T/100BASE-TX INTEGRATED PHYCEIVER WITH RMII INTERFACE

ICS1894-40
10BASE-T/100BASE-TX INTEGRATED PHYCEIVER WITH RMII INTERFACE
PHYCEIVER
Pins for Monitoring the Data Link table
Pin
P0AC
P1CL
P2LI
P3TD
P4RD
LED Driven by the Pin’s Output Signal
AC (Link Activity) LED
CL (Collisions) LED
LI (Link Integrity) LED
TD (Transmit Data) LED
RD (Receive Data) LED
Note:
1. During either a power-on reset or a hardware reset, each
multi-function configuration pin is an input that is sampled
when the ICS1894-40 exits the reset state. After sampling is
complete, these pins are output pins that can drive status
LEDs.
2. A software reset does not affect the state of a
multi-function configuration pin. During a software reset, all
multi-function configuration pins are outputs.
3. Each multi-function configuration pin must be pulled
either up or down with a resistor to establish the address of
the ICS1894-40. LEDs may be placed in series with these
resistors to provide a designated status indicator as
described in the Pins for Monitoring the Data Link table. Use
1KΩ resistors.
Caution: All pins listed in the Pins for Monitoring the Data
Link table must not float.
4. As outputs, the asserted state of a multi-function
configuration pin is the inverse of the sense sampled during
reset. This inversion provides a signal that can illuminate an
LED during an asserted state. For example, if a
multi-function configuration pin is pulled down to ground
through an LED and a current-limiting resistor, then the
sampled sense of the input is low. To illuminate this LED for
the asserted state, the output is driven high.
5. Adding 10KΩ resistors across the LEDs ensures the PHY
address is fully defined during slow VDD power-ramp
conditions.
6. PHY address 00 tri-states the MII interface. (Do not select
PHY address 00 unless you want the MII tri-stated.)
The following figure shows typical biasing and LED connections for the ICS1894-40.
P4/LED2
38
P3/RXD2
19
RXD2
ICS1894CK-40
P2//INT
12
P1/LED1
40
INT
P0/LED0
39
LED2
10KΩ
10KΩ
10KΩ
LED1 10KΩ
VDD
1KΩ
1KΩ
1KΩ
LED0 10KΩ
This circuit decodes to PHY address = 1
IDT™ / ICS™ 10BASE-T/100BASE-TX INTEGRATED PHYCEIVER WITH RMII INTERFACE 14
ICS1894-40 REV C 092909