
XRT84L38
349
REV. 1.0.1
Set the read-only Receive Yellow Alarm State bit of the Alarm and Error Status Register (AESR) to one
indicating there is Yellow Alarm detected in the incoming DS1 frame.
Set the Receive Yellow Alarm State Change bit of the Alarm and Error Status Register to one indicating there
is a change in state of Yellow Alarm. This status indicator is valid until the Framer Interrupt Status Register is
read.
OCTAL T1/E1/J1 FRAMER
Reading this register clears the associated interrupt if Reset-Upon-Read is selected in Interrupt Control
Register (ICR). Otherwise, a write-to-clear operation by the microprocessor is required to reset these status
indicators.
The table below shows the Receive Yellow Alarm State Change status bits of the Alarm and Error Status
Register.
ALARM AND ERROR STATUS REGISTER (AESR) (INDIRECT ADDRESS = 0XNAH, 0X02H)
The table below shows the Receive AIS State Change status bits of the Alarm and Error Status Register.
The Receive Yellow Alarm State bit of the Alarm and Error Status Register (AESR), on the other hand, is a
read-only bit indicating there is Yellow Alarm detected in the incoming DS1 frame.
The table below shows the Receive Yellow Alarm State status bits of the Alarm and Error Status Register.
ALARM AND ERROR STATUS REGISTER (AESR) (INDIRECT ADDRESS = 0XNAH, 0X02H)
10.6.4
How to configure the framer to detect Bipolar Violation
The line coding for the DS1 signal should be bipolar. That is, a binary "0" is transmitted as zero volts while a
binary "1" is transmitted as either a positive or negative pulse, opposite in polarity to the previous pulse. A
Bipolar Violation or BPV occurs when the alternate polarity rule is violated. The Alarm indication logic within the
Receive Framer block of the XRT84L38 framer monitors the incoming DS1 frames for Bipolar Violations.
If a Bipolar Violation is present in the incoming DS1 frame, the XRT84L38 framer can generate a Receive
Bipolar Violation interrupt associated with the setting of Receive Bipolar Violation bit of the Alarm and Error
Status Register to one.
To enable the Receive Bipolar Violation interrupt, the Receive Bipolar Violation Interrupt Enable bit of the Alarm
and Error Interrupt Enable Register (AEIER) has to be set to one. In addition, the Alarm and Error Interrupt
Enable bit of the Block Interrupt Enable Register (BIER) needs to be one.
B
IT
N
UMBER
B
IT
N
AME
B
IT
T
YPE
B
IT
D
ESCRIPTION
0
Receive Yellow
Alarm State
Change
RUR /
WC
0 - There is no change of Yellow Alarm state in the incoming DS1 payload
data.
1 - There is change of Yellow Alarm state in the incoming DS1 payload
data.
B
IT
N
UMBER
B
IT
N
AME
B
IT
T
YPE
B
IT
D
ESCRIPTION
5
Receive Yellow
Alarm State
R
0 - There is no Yellow Alarm condition detected in the incoming DS1 pay-
load data.
1 - There is Yellow Alarm condition detected in the incoming DS1 payload
data.