XR72L52 Datasheet, PDF (71/480 Pages) Exar Corporation – TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

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TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
2.3.2.8 Receive DS3 Configuration & Status Register
RXDS3 CONFIGURATION & STATUS REGISTER (ADDRESS = 0X10)
BIT 7
RxAIS
BIT 6
RxLOS
BIT 5
RxIdle
BIT 4
RxOOF
BIT 3
Reserved
BIT 2
Framing On
Parity
RO
RO
RO
RO
RO
R/W
0
0
0
0
X
0
BIT 1
FSync
Algo
R/W
0
XRT72L52
REV. 1.0.1
BIT 0
MSync
Algo
R/W
0
Bit 7 - RxAIS (Receive AIS Pattern) Indicator
This Read-Only bit-field indicates whether or not the Receive Section of the channel is currently receiving an
AIS pattern.
The channel will set this bit-field to "0" if it is not currently detecting an AIS pattern in the incoming data stream.
The channel will set this bit-field to "1" if it is currently receiving an AIS pattern in the incoming data stream.
NOTE: For a more detailed discussion on the AIS pattern for DS3 applications, refer to Section 4.3.2.5.2
Bit 6 - RxLOS (Receive LOS Condition) Indicator
This Read-Only bit-field indicates whether or not the Receive Section of the channel is currently declaring an
LOS condition of the incoming DS3 or E3 data stream.
If this bit-field is set to "0", then the Receive Section is currently not declaring an LOS condition.
If this bit-field is set to "1", then the Receive Section is currently declaring an LOS condition.
NOTE: For more information on the LOS Declaration criteria, for DS3 or E3 applications, refer to Section 4.3.2.5.1.
Bit 5 - RxIdle (Receive Idle Pattern) Indicator
This Read-Only bit-field indicates whether or not the Receive Section of the channel is currently detecting the
Idle-pattern in the incoming DS3 data stream. This bit-field is relevant for DS3 applications only.
If this bit-field is set to "0" then the Receive Section is currently not detecting the Idle-pattern in the incoming
DS3 data stream.
If this bit-field is set to "1" then the Receive Section is currently detecting the Idle pattern in the incoming DS3
data stream.
NOTE: For more information on the Idle Pattern, refer to Section 4.3.2.5.3
Bit 4 - RxOOF (Receive Out-of-Frame) Indicator
This Read-Only bit-field indicates whether or not the Receive Section of the channel is currently declaring an
OOF condition.
If this bit-field is set to "0", then the Receive Section is currently not declaring the OOF condition.
If this bit-field is set to "1", then the Receive Section is currently declaring the OOF condition.
NOTE: For more information on the OOF Declaration criteria, for DS3 applications, refer to Section 4.3.2.2.
Bit 3 - Reserved
Bit 2 - Framing On Parity ON/OFF Select
This Read/Write bit field allows the user to require that the Receive DS3/E3 Framer block include Parity (P-bit)
verification as a condition for declaring itself In-Frame during Frame Acquisition. This requirement will be im-
posed in addition to those criteria selected via Bits 0 and 1 of this register.
This feature also imposes an additional Frame Maintenance requirement on the Receive DS3/E3 Framer
block, in addition to the requirements specified in the user's selection of Bits 0 and 1 of this register. In particu-
lar, if this additional requirement is implemented, the Receive DS3/E3 Framer block will perform a frame
search if it detects P-bit errors in at least 2 out of 5 DS3 Frames. Writing a "1" to this bit-field imposes these
additional requirements. Whereas, writing a '0' causes the Receive DS3/E3 Framer block to waive this require-
ment.
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