XRT84L38IB Exar Corporation, XRT84L38IB Datasheet - Page 351

• Manufacturer Part Number: XRT84L38IB
• Description: Network Controller & Processor ICs 8 Ch T1/E1 Framer
• Manufacturer: Exar Corporation

Specifications of XRT84L38IB

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

REV. 1.0.1
The Transmit Alarm Indication Signal Select [1:0] bits of the Alarm Generation Register (AGR) enable the two
types of AIS transmission that are supported by the XRT84L38 framer. The table below shows configurations
of the Transmit Alarm Indication Signal Select [1:0] bits of the Alarm Generation Register (AGR).
ALARM GENERATION REGISTER (AGR) (INDIRECT ADDRESS = 0XN0H, 0X08H)
Upon detection of Loss of Signal (LOS) or Loss of Frame (LOF) condition, the Repeater will generate an
internal Red Alarm when enabled. This alarm will normally trigger a microprocessor interrupt informing the user
that an incoming signal failure is happening.
The Loss of Frame Declaration Enable bit of the Alarm Generation Register (AGR) enable the generation of
Red Alarm. The table below shows configurations of the of Frame Declaration Enable bit of the Alarm
Generation Register (AGR).
ALARM GENERATION REGISTER (AGR) (INDIRECT ADDRESS = 0XN0H, 0X08H)
Upon detection of Loss of Signal (LOS) or Loss of Frame (LOF) condition, the receiver will transmit the Yellow
Alarm back to the source indicating the loss of an incoming signal. This Yellow Alarm informs the source that
there is a problem further down the line and its transmission is not being received at the destination.
The XRT84L38 framer supports transmission of Yellow Alarm when running at the following framing formats:
•
•
•
•
Yellow alarm is transmitted in different forms for various framing formats. The Yellow Alarm Generation Select
[1:0] bits of the Alarm Generation Register (AGR) enable transmission of different types of Yellow alarm that
are supported by the XRT84L38 framer.
9.6.3
9.6.4
9.6.4.1
N
N
SF Mode
ESF Mode
N Mode
T1DM Mode
UMBER
UMBER
B
3-2
B
6
IT
IT
How to configure the framer to generate Red Alarm
How to configure the framer to transmit Yellow Alarm
Declaration Enable
Transmit Yellow Alarm in SF Mode
Loss of Frame
Transmit AIS
B
B
IT
Select
IT
N
N
AME
AME
B
B
IT
IT
R/W
R/W
T
T
YPE
YPE
These READ/WRITE bit-fields allows the user to choose which one of the
two AIS pattern supported by the XRT84L38 framer will be transmitted.
00 - No AIS alarm is generated.
01 - Enable unframed AIS alarm of all ones pattern.
10 - Enable framed AIS alarm of all ones pattern except for framing bits.
11 - No AIS alarm is generated.
This READ/WRITE bit-field permits the framer to declare Red Alarm in
case of Loss of Frame Alignment (LOF).
When receiver module of the framer detects Loss of Frame Alignment in
the incoming data stream, it will generate a Red Alarm. The framer will
also generate an RxLOFs interrupt to notify the microprocessor that an
LOF condition is occurred. A Yellow Alarm is then returned to the remote
transmitter to report that the local receiver detects LOF.
0 - Red Alarm declaration is disabled.
1 - Red Alarm declaration is enabled.
331
B
B
IT
IT
D
D
ESCRIPTION
ESCRIPTION
OCTAL T1/E1/J1 FRAMER
XRT84L38