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IDT82P2281
SINGLE T1/E1/J1 LONG HAUL / SHORT HAUL TRANSCEIVER
Functional Description
52
August 20, 2009
3.10
ALARM DETECTOR
3.10.1
T1/J1 MODE
The RED alarm, Yellow alarm and Blue alarm are detected in this
The status of the RED alarm, Yellow alarm and Blue alarm are indi-
cated by the corresponding Status bit. Any transition (from ‘0’ to ‘1’ or
from ‘1’ to ‘0’) on the Status bit will set the corresponding Interrupt Indi-
cation bit to ‘1’ and the Interrupt Indication bit will be cleared by writing a
‘1’. A ‘1’ in the Interrupt Indication bit means there is an interrupt. The
interrupt will be reported by the INT pin if its Interrupt Enable bit is ‘1’.
Table 26: RED Alarm, Yellow Alarm & Blue Alarm Criteria
Declare Condition
Clear Condition
Status Bit Interrupt Indication Bit Interrupt Enable Bit
RED Alarm
(per T1.403,
T1.231)
The out of SF/ESF/T1 DM/SLC-96 syn-
chronization status persists Nx40 ms. Here
‘N’ is decided by the REDDTH[7:0] bits.
The in SF/ESF/T1 DM/SLC-96 synchro-
nization status persists Mx120 ms. Here
‘M’ is decided by the REDCTH[7:0] bits.
RED
REDI
REDE
Yellow
Alarm*
T1 SF/
SLC-96
Format
Less than 77 ’One’s are detected on the Bit
2 of each channel during a 40 ms fixed win-
dow and this status persists for Nx40 ms.
Here ‘N’ is decided by the YELDTH[7:0]
bits.
More than 76 ’One’s are detected on the
Bit 2 of each channel during a 40 ms
fixed window and this status persists for
Mx40 ms. Here ‘M’ is decided by the
YELCTH[7:0] bits.
YEL
YELI
YELE
T1 ESF
Format
More than 7 ‘0xFF00’ (MSB first) are
detected on the DL bits during a 40 ms
fixed window and this status persists for
Nx40 ms. Here ‘N’ is decided by the
YELDTH[7:0] bits.
Less than 8 ‘0xFF00’ (MSB first) are
detected on the DL bits during a 40 ms
fixed window and this status persists for
Mx40 ms. Here ‘M’ is decided by the
YELCTH[7:0] bits.
YEL
YELI
YELE
T1 DM
Format
Less than 4 ’One’s are detected on the Y
bit (Bit 6 in each CH 24) during a 40 ms
fixed window and this status persists for
Nx40 ms. Here ‘N’ is decided by the
YELDTH[7:0] bits.
More than 3 ’One’s are detected on the
Y bit (Bit 6 in each CH 24) during a 40
ms fixed window and this status persists
for Mx40 ms. Here ‘M’ is decided by the
YELCTH[7:0] bits.
YEL
YELI
YELE
J1 SF
Format
Less than 4 zeros are detected on the F-bit
of the 12nd frame during a 40 ms fixed win-
dow and this status persists for Nx40 ms.
Here ‘N’ is decided by the YELDTH[7:0]
bits.
More than 3 zeros are detected on the
F-bit of the 12nd frame during a 40 ms
fixed window and this status persists for
Mx40 ms. Here ‘M’ is decided by the
YELCTH[7:0] bits.
YEL
YELI
YELE
J1 ESF
Format
Less than 3 zeros are detected on the DL
bits during a 40 ms fixed window and this
status persists for Nx40 ms. Here ‘N’ is
decided by the YELDTH[7:0] bits.
More than 2 zeros are detected on the
DL bits during a 40 ms fixed window and
this status persists for Mx40 ms. Here
‘M’ is decided by the YELCTH[7:0] bits.
YEL
YELI
YELE
Blue Alarm
(per T1.231)
Less than 61 zeros are detected in a 40 ms
fixed window and this status persists for
Nx40 ms. Here ‘N’ is decided by the AIS-
DTH[7:0] bits.
More than 60 zeros are detected in a 40
ms fixed window and this status persists
for Mx40 ms. Here ‘M’ is decided by the
AISCTH[7:0] bits.
AIS
AISI
AISE
Note: * The Yellow Alarm can only be detected when the frame is synchronized.