
20
x r
PRELIMINARY
E3 UNI FOR ATM
XRT7234
REV. P1.0.0
26
RLOOP
O
Remote Loopback Output Pin (to the XR-T7296 E3 Line Transmitter
IC).
This output pin is intended to be connected to the RLOOP input pin of
the XR-T7296 E3 Line Transmitter IC. The user can command this signal
to toggle “high” and, in turn, force the XR-T7296 E3 Line Transmitter into
the “Remote Loopback” mode. Conversely, the user can command this
signal to toggle “l(fā)ow” and allow the XR-T7296 device to operate in the
normal mode. (For a detailed description of the XR-T7296 E3 Line Trans-
mitter’s operation during Remote Loopback, please see the XR-T7296
E3/STS-1, E3 Integrated Line Transmitter’s Data Sheet).
Writing a “1” to bit 1 of the “Line Interface Drive Register (Address = 84h)
will cause this output pin to toggle “high”. Writing a “0” to this bit-field will
cause the RLOOP output to toggle “l(fā)ow”.
Note:
If the customer is not using the XR-T7296 E3 Line Transmitter IC,
then he/she can use this output pin for a variety of other purposes.
21
27
D0
I/O
Bi-directional Data bus (Microprocessor Interface Section):
(Please
see description for D15)
28
LLOOP
O
Local Loopback Output Pin (to the XR-T7296 E3 Line Transmitter IC).
This output pin is intended to be connected to the LLOOP input pin of the
XR-T7296 LIU IC. The user can command this signal to toggle “high”
and, in turn, force the LIU into the “Local Loopback” mode. (For a detailed
description of the XR-T7296 E3 Line Transmitter’s operation during Local
Loopback, please see the XR-T7296 E3/STS-1, E3 Integrated Line
Transmitter’s Data Sheet).
Writing a “1” to bit 1 of the “Line Interface Drive Register (Address = 84h)
will cause this output pin to toggle “high”. Writing a “0” to this bit-field will
cause the RLOOP output to toggle “l(fā)ow”.
Note:
If the user is not using the XR-T7296 E3 Line Transmitter IC, then
he/she can use this output pin for a variety of other purposes.
22
29
IntB*
O
Interrupt Request Output:
This open-drain, active-low output signal will
be asserted when the UNI device is requesting interrupt service from the
local microprocessor. This output pin should typically be connected to
the “Interrupt Request” input of the local microprocessor.
30
RxLCD
O
Loss of Cell Delineation Indicator:
This active-high output pin will be
asserted whenever the Receive Cell Processor has experienced a “Loss of
Cell Delineation”. This pin will return “l(fā)ow” once the Receive Cell Processor
has regained Cell Delineation.
23
31
GND
***
Ground Pin Signal
PIN DESCRIPTION (CONTINUED)
Pin
No.
100 Pin Package
Pin No. 160
PinPackage
Symbol
Type
Description