ICS1893Y-10 Datasheet, PDF (106/150 Pages) –

ICS1893Y-10 Data Sheet - Release
Chapter 8 Pin Diagram, Listings, and Descriptions
8.3.2 Multi-Function (Multiplexed) Pins: PHY Address and LED Pins
Table 8-3 lists the pins for the multi-function group of pins (that is, the multiplexed PHY Address / LED pins).
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 ICS1893Y-10 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 ICS1893Y-10. LEDs placed in series with these resistors provide a designated status
indicator.
Caution: All pins listed in Table 8-3 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 an LED for the
asserted state requires the output to be high.
Note: Each of these pins monitor the data link by providing signals that directly drive LEDs.
Table 8-3. PHY Address and LED Pins
Pin
Name
P0AC
Pin
Number
55
Pin
Type
Input or
Output
Pin Description
PHY (Address Bit) 0 / Activity LED.
For more information on this pin, see Section 5.5, “Twisted-Pair Interface”.
• This multi-function configuration pin is:
– An input pin during either a power-on reset or a hardware reset. In
this case, this pin configures the ICS1893Y-10 when it is in either
hardware mode or software mode.
– An output pin following reset. In this case, this pin provides activity
status of the ICS1893Y-10.
As an input pin:
• This pin establishes the address for the ICS1893Y-10. When the signal
on this pin is logic:
– Low, that address bit is set to logic zero.
– High, that address bit is set to logic one.
As an output pin:
• When the signal on this pin is:
– De-asserted, this state indicates the ICS1893Y-10 does not have
Transmit or Receive activity.
– Asserted, this state indicates the ICS1893Y-10 has Transmit or
Receive activity.
Caution: This pin must not float. (See the notes at Section 8.3.2,
“Multi-Function (Multiplexed) Pins: PHY Address and LED
Pins”.)
ICS1893Y-10 Rev F 1/20/04
Copyright © 2004, Integrated Circuit Systems, Inc.
All rights reserved.
106
January, 2004