
PRELIMINARY
XRT86SH328
267
REV. P1.0.6
28-CHANNEL DS1/E1 FRAMER/LIU WITH DS3 MUX & VT-MAPPER - SONET APPLICATIONS
The Transmit DS1 Framer block will insure that there is a minimum of a one-second delay between the time
that it terminates transmission of the RAI indicator, and the instant that it proceeds to transmit the RAI
indicator again.
Transmission of the RAI Indicator when the One Second Rule is NOT in-force
If the user does NOT invoke the One Second Rule, then the following will happen.
Whenever the Transmit DS1 Framer block generates and transmits the RAI indicator, it will do so for at least
one second (for both the ESF and the SF framing formats).
The Transmit DS1 Framer block will NOT insure that there is a minimum of a one-second delay between the
time that it terminates transmission of the RAI indicator, and the instant that it proceeds to transmit the RAI
indicator again.
`
0 = Does not configure the Transmit DS1 Framer block to transmit the RAI indicator per the One Second Rule.
`
1 = Configures the Transmit DS1 Framer block to transmit the RAI indicator per the One Second Rule.
BIT6 - Transmit Yellow Alarm:
BIT [5:4] - Yellow Alarm Format[1:0]:
BIT [3:2] - Transmit AIS Pattern Select[1:0]:
These two READ/WRITE bit-fields serves the following two functions.
To command the Transmit DS1 Framer block to transmit the AIS indicator (per Software Command), and
To specify the type of AIS Pattern that the Transmit DS1 Framer block will transmit, whenever it has been
commanded to transmit the AIS indicator to the remote terminal equipment.
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 DS1 Framer block will
look for in order to determine whether or not it should declare or clear the AIS defect condition
The Relationship between Transmit AIS Pattern Select[1:0] and the resulting behavior of the
Transmit DS1 Framer block
T
RANSMIT
AIS P
ATTERN
S
ELECT
[1:0]
T
RANSMIT
DS1 F
RAMER
B
LOCK
A
CTION
00/10
Transmits Normal TrafficTransmit DS1 Framer block does not transmit the AIS indi-
cator. It will (instead) transmit normal traffic
01
Unframed All Ones PatternThe Transmit DS1 Framer block will transmit an
Unframed All Ones Pattern (as an AIS pattern) for the duration that these bit-fields
are set to [0, 1].
11
Framed All Ones PatternThe Transmit DS1 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 DS1 Framer block will look for in declaring/clearing the AIS defect condition
AIS D
EFECT
D
ECLARATION
C
RITERIA
[1:0]
R
ECEIVE
DS1 F
RAMER
B
LOCK
- AIS D
EFECT
D
ECLARATION
C
RITERIA
00/10
AIS Defect Declaration is DisabledThe Receive DS1 Framer block will NOT declare
the AIS defect condition at all.
01
Unframed and Framed All Ones Pattern:The Receive DS1 Framer block will declare
the AIS defect condition whenever it receives either the Framed or Unframed All Ones
pattern for at least 42ms.
11
Framed All Ones Pattern:The Receive DS1 Framer block will only declare the AIS
defect condition whenever it receives the Framed All Ones Pattern for at least 42ms.