
PRELIMINARY
XRT86SH328
299
REV. P1.0.6
28-CHANNEL DS1/E1 FRAMER/LIU WITH DS3 MUX & VT-MAPPER - SONET APPLICATIONS
BIT[1:0] - AIS Defect Declaration Criteria[1:0]
These two READ/WRITE bit-fields are used to select the type of AIS Pattern that the Receive E1 Framer block will look
for in order to determine whether or not it should declare or clear the AIS defect condition.
BIT [7:6] - E-Bit Source Select
These bits are used to specify the source of E-bits wihin each outbound E1 frame.
10
The AIS-16 PatternIn this case, time slot 16 in each frame will be set to an All Ones
Pattern.
11
Framed All Ones PatternThe Transmit E1 Framer block will transmit a Framed All
Ones Pattern (as an AIS pattern) for the duration that these bit-fields are set to [1, 0].
The Relationship between AIS Defect Declaration Criteria[1:0] and the resulting AIS Pattern that the
Receive E1 Framer block will look for in declaring/clearing the AIS defect condition
AIS D
EFECT
D
ECLARATION
C
RITERIA
[1:0]
R
ECEIVE
E1 F
RAMER
B
LOCK
- AIS D
EFECT
D
ECLARATION
C
RITERIA
00
AIS Defect Declaration is DisabledThe Receive E1 Framer block will NOT declare
the AIS defect condition at all.
01
Unframed and Framed All Ones Pattern:The Receive E1 Framer block will
declare the AIS defect condition whenever it receives either the Framed or
Unframed All Ones pattern for at least 42ms.
10
AIS-16 All Ones Pattern:The Receive E1 Framer block will declare the AIS defect
condition whenever it receives all ones in the 16th time slot.
11
Framed All Ones Pattern:The Receive E1 Framer block will only declare the AIS
defect condition whenever it receives the Framed All Ones Pattern for at least
42ms.
T
ABLE
436: E1 F
RAMER
B
LOCK
- S
YNCHRONIZATION
MUX R
EGISTER
(A
DDRESS
= 0
X
N109,
WHERE
N
RANGES
IN
VALUE
FROM
0
X
01
TO
0
X
38)
BIT7
BIT6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
E-Bit SourceSelect
Reserved
Data Link SourceSelect
CRC-4
Source
Select
Framing
Alignment
Pattern
Select
R/O
R/W
R/W
R/W
R/O
R/O
R/W
R/W
0
0
0
0
0
0
0
0
E-bits
E-
BITS
[1:0]
E-B
IT
S
OURCE
S
ELECT
00
Internal Framer BlockThe E-bits are used to indicate whether the receive E1 framer
block has detected a CRC error within the most recently received sub-multi frame.
The receive E1 framer will indicate a received errored sub-multi frame by setting the
binary state of the E-bits from 1 to 0 for each errored sub-multi frame.
The Relationship between Transmit AIS Pattern Select[1:0] and the resulting behavior of the Transmit
E1 Framer block
T
RANSMIT
AIS P
ATTERN
S
ELECT
[1:0]
T
RANSMIT
E1 F
RAMER
B
LOCK
A
CTION