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XRT79L71
PRELIMINARY
211
1-CHANNEL DS3/E3 CLEAR-CHANNEL FRAMERLIU COMBO - CC/HDLC ARCHITECTURE
REV. P2.0.0
The Payload portion of the DS3 Frame exhibits a repeating "1010..." pattern
Configuring the Receive DS3/E3 Framer block to only declare the AIS defect condition whenever it
detects the Bellcore GR-499-CORE Compliant AIS pattern
To configure the Receive DS3/E3 Framer block to declare the AIS defect condition whenever it detects the
Bellcore GR-499-CORE Compliant AIS pattern thent make sure that Bits 6 (DS3 AIS Non Stuck Stuff) and 7
(DS3 AIS Unframed All Ones) within the Receive DS3 Pattern Register are set to "0" as depicted below.
Declaring the AIS Defect condition in response to the Relaxed Bellcore GR-499-CORE Standard AIS
signal
The Receive DS3 Framer block can be configured such that it will identify and declare the AIS defect condition
if it detects all of the following conditions in the incoming DS3 data-stream.
Valid M-bits, F-bits and P-bits
X-bits are set to "1"
The Payload portion of the DS3 Frame exhibits a repeating "1010…" pattern
C-bits are NOT necessarily set to "0"
Configuring the Receive DS3/E3 Framer block to only declare the AIS defect condition whenever it
detects the Relaxed Bellcore GR-499-CORE Compliant AIS pattern
To configure the Receive DS3/E3 Framer block to declare the AIS defect condition whenever it detects the
Relaxsed Bellcore GR-499-CORE Compliant AIS pattern then make sure that Bit 6 (DS3 AIS Non Stuck Stuff)
and Bit 7 (DS3 AIS Unframed All Ones), within the Receive DS3 Pattern Register are set to "1" and "0"
respectively, as depicted below.
Declaring the AIS Defect condition in response to the Unframed, "All Ones" DS3 AIS signal
The Receive DS3 Framer block can be configured such that it will identify and declare the AIS defect condition
it is detects an Unframed "All Ones" pattern in the incoming DS3 data-stream
Configuring the Receive DS3/E3 Framer block to only declare the AIS defect condition whenever it
detects the Unframed, All Ones Pattern
Receive DS3 Pattern Register (Address = 0x112F)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
DS3 AIS-
Unframed
All Ones
DS3 AIS
-Non Stuck
Stuff
Unused
Receive LOS
Pattern
Receive DS3 Idle Pattern[3:0]
R/W
R/O
R/W
0
1
0
Receive DS3 Pattern Register (Address = 0x112F)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
DS3 AIS
-Unframed
All Ones
DS3 AIS
-Non Stuck
Stuff
Unused
Receive LOS
Pattern
Receive DS3 Idle Pattern[3:0]
R/W
R/O
R/W
0
1
0
1
0