
Data Sheet
615
Rev. 1.2, 2006-01-26
QuadFALCTM
PEF 22554 E
T1/J1 Registers
Interrupt Status Register 2
All bits are reset when ISR2 is read. If bit GCR.VIS is set, interrupt statuses in ISR2 are flagged although they are
masked by register IMR2. However, these masked interrupt statuses neither generate a signal on INT (or INT1,
ISR2_T
Offset
Reset Value
Interrupt Status Register 2
xx6AH
00H
Field
Bits
Type
Description
FAR
7
r
Frame Alignment Recovery
The framer has reached synchronization. Set with the falling edge of bit
FRS0.LFA. It is set also after alarm simulation is finished and the receiver
is still synchronous.
LFA
6
r
Loss of Frame Alignment
The framer has lost synchronization and bit FRS0.LFA is set. It is set
during alarm simulation.
MFAR
5
r
Multiframe Alignment Recovery
Set when the framer has reached multiframe alignment in F12 or F72
format. With the negative transition of bit FRS0.LMFA this bit is set. It is
set during alarm simulation.
LMFA
4
r
Loss of Multiframe Alignment
Set when the framer has lost the multiframe alignment in F12 or F72
format. With the positive transition of bit FRS0.LMFA this bit is set. It is
set during alarm simulation.
AIS
3
r
Alarm Indication Signal (Blue Alarm)
This bit is set when an alarm indication signal is detected and bit
FRS0.AIS is set. If GCR.SCI is set high this interrupt status bit is activated
with every change of state of FRS0.AIS.It is set during alarm simulation.
LOS
2
r
Loss-of-Signal (Red Alarm)
This bit is set when a loss-of-signal alarm is detected in the received data
stream and FRS0.LOS is set. If GCR.SCI is set high this interrupt status
bit is activated with every change of state of FRS0.LOS. It is set during
alarm simulation.
RAR
1
r
Remote Alarm Recovery
Set if a remote alarm (yellow alarm) is cleared and bit FRS0.RRA is reset.
It is set also after alarm simulation is finished and no remote alarm is
detected.
RA
0
r
Remote Alarm
A remote alarm (yellow alarm) is detected. Set with the rising edge of bit
FRS0.RRA. It is set during alarm simulation.