XR72L52 Datasheet, PDF (80/480 Pages) Exar Corporation – TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

XRT72L52
REV. 1.0.1
xr
TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
2.3.3.2 Receive E3 Configuration & Status Register 2 (E3, ITU-T G.832)
RXE3 CONFIGURATION & STATUS REGISTER 2 (ADDRESS = 0X11)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Rx LOF Algo RxLOF
RxOOF
RxLOS
RxAIS RxPld Unstab RxTMark
RxFERF
R/W
RO
RO
RO
RO
RO
RO
RO
0
1
1
1
0
0
1
0
Bit 7 - RxLOF Algo (Loss of Frame Declaration Algorithm)
This Read/Write bit-field allows the user to select the LOF (Loss of Frame) Declaration criteria, that will be
used by the Receive DS3/E3 Framer. Writing a "0" to this bit-field configures the Receive DS3/E3 Framer to
declare an LOF condition, after it has been in the OOF condition for 24 frame periods (3 ms). Writing a "1" to
this bit-field configures the Receive DS3/E3 Framer to declare an LOF condition, after it has been in the OOF
condition for 8 frame periods (1 ms).
Bit 6 - RxLOF (Loss of Frame Declaration)
This Read-Only bit-field indicates whether or not the Receive DS3/E3 Framer block is currently in the Loss of
Frame (LOF) condition. If this bit-field is set to "1", then the Receive DS3/E3 Framer block is currently in the
LOF condition. Conversely, if this bit-field is set to "0", then the Receive DS3/E3 Framer block is currently not
in the LOF condition.
Bit 5 - RxOOF (Out of Frame Declaration)
This Read-Only bit field indicates whether or not the Receive DS3/E3 Framer block is currently experiencing
an Out of Frame (OOF) condition. The Receive DS3/E3 Framer block will declare an OOF condition if it has
detected errors in the frame alignment bytes (FA1 and FA2) in four consecutive frames. If this bit-field is set to
"1", then the Receive DS3/E3 Framer block has declared, and is continuing to experience an OOF condition. If
this bit-field is set to "0", then the Receive DS3/E3 Framer block is currently not experiencing an OOF condi-
tion.
Bit 4 - RxLOS (Loss of Signal Declaration)
This Read-Only bit-field indicates whether or not the Receive DS3/E3 Framer block is currently experiencing a
Loss of Signal (LOS) condition. The Receive DS3/E3 Framer block will declare an LOS condition if it has de-
tected a string of 32 consecutive "0’s", via the RxPOS and RxNEG input pins. If this bit-field is set to "1", then
the Receive DS3/E3 Framer block has declared, and is continuing to experience an LOS condition. If this bit-
field is set to "0", then the Receive DS3/E3 Framer block is currently not experiencing an LOS condition.
Bit 3 - RxAIS (Alarm Indication Status Declaration)
This Read-Only bit-field indicates whether or not the Receive DS3/E3 Framer block is currently experiencing
an AIS condition. The Receive DS3/E3 Framer block will declare an AIS condition if it has detected two con-
secutive E3 frames, that each contain less than seven (7) "0’s" . If this bit-field is set to "1", then the Receive
DS3/E3 Framer block has declared, and is continuing to experience an AIS condition. If this bit-field is set to
"0", then the Receive DS3/E3 Framer block is currently not experiencing an AIS condition.
Bit 2 - RxPLDType UnStab
This Read-Only bit-field indicates whether or not the Receive DS3/E3 Framer block has been receiving a con-
sistent Payload Type value (within the MA Byte-Field) in the last 5 consecutive incoming E3 frames.
If the Receive DS3/E3 Framer block has detected a change in the Payload Type value, within the last 5 incom-
ing E3 frames, then it will set this bit-field to "1". If the Payload Type value has been consistent in the last 5 E3
frames, then the Receive DS3/E3 Framer block will set this bit-field to "0".
Bit 1 - Rx TMark
This Read-Only bit-field reflects the most recently validated Timing Marker value. The Receive DS3/E3 Fram-
er block will validate the Timing Marker state, after it has detected a user-selectable number of consecutive in-
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