
XRT86L30
SINGLE T1/E1/J1 FRAMER/LIU COMBO
REV. P1.0.1
The table below shows the Receive Yellow Alarm State status bits of the Alarm and Error Status Register.
PRELIMINARY
233
12.4 B
IPOLAR
V
IOLATION
The line coding for the DS1 signal should be bipolar. That is, a binary "0" is transmitted as zero volts while a bi-
nary "1" is transmitted as either a positive or negative pulse, opposite in polarity to the previous pulse. A Bipo-
lar Violation or BPV occurs when the alternate polarity rule is violated. The Alarm indication logic within the Re-
ceive Framer block of the XRT86L30 framer monitors the incoming DS1 frames for Bipolar Violations.
If a Bipolar Violation is present in the incoming DS1 frame, the XRT86L30 framer can generate a Receive Bi-
polar Violation interrupt associated with the setting of Receive Bipolar Violation bit of the Alarm and Error Sta-
tus 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 En-
able bit of the Block Interrupt Enable Register (BIER) needs to be one.
The table below shows configurations of the Receive Bipolar Violation Interrupt Enable bit of the Alarm and Er-
ror Interrupt Enable Register (AEIER).
The table below shows configurations of the Alarm and Error Interrupt Enable bit of the Block Interrupt Enable
Register.
When these interrupt enable bits are set and one or more Bipolar Violations are present in the incoming DS1
frame, the XRT86L30 framer will declare Receive Bipolar Violation by doing the following:
Set the Receive Bipolar Violation bit of the Alarm and Error Status Register to one indicating there are one or
more Bipolar Violations. This status indicator is valid until the Framer Interrupt Status Register is read.
Reading this register clears the associated interrupt if Reset-Upon-Read is selected in Interrupt Control Regis-
ter (ICR). Otherwise, a write-to-clear operation by the microprocessor is required to reset these status indica-
tors.
ALARM AND ERROR STATUS REGISTER (AESR) (ADDRESS = 0X0B02H)
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 payload
data.
1 - There is Yellow Alarm condition detected in the incoming DS1 payload data.
ALARM AND ERROR INTERRUPT ENABLE REGISTER (AEIER) (ADDRESS = 0X0B03H)
B
IT
N
UMBER
B
IT
N
AME
B
IT
T
YPE
B
IT
D
ESCRIPTION
3
Receive Bipolar Vio-
lation Interrupt
Enable
R/W
0 - The Receive Bipolar Violation interrupt is disabled. Occurrence of one or more
bipolar violations will not generate an interrupt.
1 - The Receive Bipolar Violation interrupt is enabled. Occurrence of one or more
bipolar violations will generate an interrupt.
BLOCK INTERRUPT ENABLE REGISTER (BIER) (ADDRESS = 0X0B01H)
B
IT
N
UMBER
B
IT
N
AME
B
IT
T
YPE
B
IT
D
ESCRIPTION
1
Alarm and Error
Interrupt Enable
R/W
0 - Every interrupt generated by the Alarm and Error Interrupt Status Register
(AEISR) is disabled.
1 - Every interrupt generated by the Alarm and Error Interrupt Status Register
(AEISR) is enabled.