XRT72L53 Datasheet, PDF (76/467 Pages) Exar Corporation – THREE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

áç THREE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
PRELIMINARY
XRT72L53
REV. P1.1.7
RXDS3 CONFIGURATION & STATUS REGISTER (ADDRESS = 0X10)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
RxAIS
RxLOS
RxIdle
RxOOF
Reserved
Framing On
Parity
RO
RO
RO
RO
RO
R/W
0
0
0
0
0
0
BIT 1
FSync
Algo
R/W
0
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, within the XRT72L53
is currently receiving an AIS pattern or not.
The channel will set this bit-field to "0" if it is not cur-
rently detecting an AIS pattern in the incoming data
stream. Conversely, 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, please see Section 3.3.2.5.2
Bit 6 - RxLOS (Receive LOS Condition) Indicator
This Read-Only bit-field indicates whether or not the
Receive Section of the channel (within the Framer) is
currently declaring an LOS (Loss of Signal) condition
of the incoming DS3 or E3 data stream.
If this bit-field is set to "0", then the Receive Section
(of the channel) is currently not declaring an LOS
condition.
If this bit-field is set to "1", then the Receive Section
(of the channel) is currently declaring an LOS condi-
tion.
NOTE: For more information on the LOS Declaration crite-
ria, for DS3 and E3 applications, please see Section
3.3.2.5.2.
Bit 5 - RxIdle (Receive Idle Pattern) Indicator
This Read-Only bit-field indicates whether or not the
Receive Section of the channel (within the Framer) is
currently detecting the Idle-pattern in the incoming
DS3 data stream.
If this bit-field is set to "0" then the Receive Section
(of the channel) is currently not detecting the Idle-pat-
tern in the incoming DS3 data stream.
If this bit-field is set to "1" then the Receive Section
(of the channel) is currently detecting the Idle pattern
in the incoming DS3 data stream.
NOTES:
1. This bit-field is only relevant for DS3 applications.
2. For more information on the Idle Pattern, please
see Section 3.3.2.5.3
Bit 4 - RxOOF (Receive Out-of-Frame) Indicator
This Read-Only bit-field indicates whether or not the
Receive Section of the channel (within the Framer) is
currently declaring an OOF (Out of Frame) condition.
If this bit-field is set to "0", then the Receive Section
(of the channel) is currently not declaring the OOF
condition.
If this bit-field is set to "1", then the Receive Section
(of the chip) is currently declaring the OOF condition.
NOTE: For more information on the OOF Declaration crite-
ria, for DS3 applications, please see Section 3.3.2.2.
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 (within the
channel) include Parity (P-bit) verification as a condi-
tion for declaring itself In-Frame, during Frame Acqui-
sition. This requirement will be imposed in addition to
those criteria selected via Bits 0 and 1 of this register.
This feature also imposes an additional Frame Main-
tenance 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 par-
ticular, 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 impos-
es these additional requirements. Whereas, writing a
'0' causes the Receive DS3/E3 Framer block to waive
this requirement.
NOTE: For more information on Framing with Parity please
see Section 3.3.2.2.
Bit 1 - F Sync Algo(rithim Select)
This 'Read/Write' bit-field, in conjunction with Bits 0
and 2 of this register, allows the user to completely
define the Frame Maintenance Criteria of the Receive
DS3/E3 Framer block. This particular bit-field allows
the user to define the Frame Maintenance Criteria as
it applies to F-bits.
If the user writes a "1" to this bit-field, then the Re-
ceive DS3/E3 Framer block will declare an Out of
Frame (OOF) condition if 3 out of 16 F-Bits are in Er-
ror. If the user writes a "0" to this bit-field, then the
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