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Advance Data Sheet
May 1998
T7633 Dual T1/E1 3.3 V Short-Haul Terminator
159
Lucent Technologies Inc.
Line Interface Alarm Register
Alarm Status Register (LIU_REG0)
Bits 0—3 of this register represent the status of the line interface receiver and transmitter alarms ALOS, DLOS,
TDM, and LOTC. The alarm indicators are active-high and automatically clear on a microprocessor read if the cor-
responding alarm conditions no longer exist. However, persistent alarm conditions will cause these bits to remain
set even after a microprocessor read. This is a read-only register.
Table 81. LIU Alarm Status Register (LIU_REG0) (400, A00)
Line Interface Alarm Interrupt Enable Register
Alarm Interrupt Enable Register (LIU_REG1)
The bits in the alarm interrupt enable register allow the user to selectively enable generation of an interrupt by each
channel alarm. The enable bits correspond to their associated alarm status bits in the alarm status register, LIU-
REG0. The interrupt enable function is active-high. When an enable bit is set, the corresponding alarm is enabled
to generate an interrupt. Otherwise, the alarm is disabled from generating an interrupt.
The enable function only impacts the ability to generate an interrupt signal. The proper alarm status will be
reflected in LIU_REG0 even when the corresponding enable bit is set to zero. Any other LIU behavior associated
with an alarm event will operate normally even if the interrupt is not enabled.
This is a read/write register.
Bit
Symbol
Description
0
ALOS
Receive Analog Loss of Signal.
A 1 indicates the LIU receive channel has detected
an analog loss of signal condition/event.
Receive Digital Loss of Signal.
A 1 indicates the LIU receive channel has detected a
digital loss of signal condition/event.
Transmit Driver Monitor Alarm.
A 1 indicates the LIU transmit channel has detected
a transmit driver monitor alarm condition/event.
Transmit Loss of Transmit Clock Alarm.
A 1 indicates the LIU transmit channel has
detected a loss of transmit clock condition/event.
Reserved.
1
DLOS
2
TDM
3
LOTC
4—7
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Table 82. LIU Alarm Interrupt Enable Register (LIU_REG1) (401, A01)
Bit
Symbol
Description
0
ALOSIE
Enable Analog Loss of Signal Interrupt.
A 1 enables an interrupt in response to
ALOS alarm.
Enable Digital Loss of Signal Interrupt.
A 1 enables an interrupt in response to
DLOS alarm.
Enable Transmit Driver Monitor Interrupt.
A 1 enables an interrupt in response to
TDM alarm.
Enable loss of Transmit Clock Interrupt.
A 1 enables an interrupt in response to
LOTC alarm.
Reserved.
Write to 0.
1
DLOSIE
2
TDMIE
3
LOTCIE
4—7
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