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IDT82P2281
SINGLE T1/E1/J1 LONG HAUL / SHORT HAUL TRANSCEIVER
Functional Description
40
October 7, 2003
3.10
ALARM DETECTOR
3.10.1
T1/J1 MODE
The RED alarm, Yellow alarm and Blue alarm are detected in this
block (refer to Table 26).
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 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 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.
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.
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.
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.
Note: * The Yellow Alarm can only be detected when the frame is synchronized.
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.
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.
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.
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.
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.
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.
YEL
YELI
YELE
T1 ESF
Format
YEL
YELI
YELE
T1 DM
Format
YEL
YELI
YELE
J1 SF
Format
YEL
YELI
YELE
J1 ESF
Format
YEL
YELI
YELE
Blue Alarm
(per T1.231)
AIS
AISI
AISE