XRT72L13 Datasheet, PDF (105/370 Pages) Exar Corporation – M13 MULTIPLEXER/CLEAR CHANNEL DS3 FRAMER IC

áç
PRELIMINARY
M13 MULTIPLEXER/CLEAR CHANNEL DS3 FRAMER IC XRT72L13
REV. 1.0.6
ticular bit-field permits the user to define the “Frame
Maintenance” criteria, as it applies to F-bits.
Setting this bit-field to “0” configures the “Receive
DS3 Framer” block to declare an “OOF” (Out of
Frame” condition) if it determines that 6 out of the last
16 F-bits are in error.
Setting this bit-field to “1” configures the “Receive
DS3 Framer” block to declare an “OOF” (Out of
Frame” condition) if it determines that 3 out of the last
16 F-bits are in error.
Bit 0 - MSync Algo(rithm) Select
This “Read/Write” bit-field, in conjunction with Bits 1
and 2 of this register, allows the user to completely
define the “Frame Maintenance” criteria of the “Re-
ceive DS3 Framer” block (within the chip). This par-
ticular bit-field permits the user to define the “Frame
Maintenance” criteria, as it applies to M-bits.
Setting this bit-field to “0” configures the “Receive
DS3 Framer” block to ignore the occurrence of M-bit
errors.
Setting this bit-field to “1” configures the “Receive
DS3 Framer” block to declare an “OOF” condition if it
determines that 3 out of 4 M-bits are in error.
2.3.2.16 RxDS3 Status Register
RX DS3 STATUS REGISTER (ADDRESS = 0X11)
BIT 7
Not Used
R/O
0
BIT 6
Not Used
R/W
0
BIT 5
Not Used
R/W
0
BIT 4
RxFERF
R/O
0
BIT 3
RxAIC
R/O
0
BIT 2
RxFEBE[2]
R/O
0
BIT 1
RxFEBE[1]
R/O
0
BIT 0
RxFEBE[0]
R/O
0
Bit 4 - RxFERF (Far-End Receive Failure) Indicator
This “Read-Only” bit-field indicates whether or not the
“Receive DS3 Framer” block (within the XRT72L13
M13 device) is declaring a FERF (Far-End Receive
Failure) condition.
If this bit-field is set to “0”, then the “Receive DS3
Framer” block (of the chip) is currently not declaring a
FERF condition.
Conversely, if this bit-field is set to “1”, then the “Re-
ceive DS3 Framer” block is currently declaring a
FERF condition.
NOTE: For more information how the “Receive DS3 Framer”
block declares a “FERF” condition, please see Section _.
Bit 3 - RxAIC (Application Identification Channel)
indicator
This “Read-Only” bit-field reflects the value of the AIC
bit-field, within the most recently received DS3
frames, as detected by the “Receive DS3 Framer”
block.
This bit-field is set to “1” if the incoming DS3 data
stream is determined to be in the “C-bit Parity” format
(AIC bit = 1) for at least 63 consecutive frames.
This bit-field is set to “0” if the incoming DS3 data
stream is determined to be in the “M13” format (AIC
bit = 0).
Bits 2 thru 0 - RxFEBE[2:0]
These “Read-Only” bit-fields reflect the “FEBE” (Far-
End Block Error) value, within the most recently re-
ceived DS3 frame.
If these bit-fields are set to “111”, then it indicates that
the “Remote” Receiving Terminal is receiving DS3
frames in an un-erred manner.
Conversely, if these bit-fields are set to any value oth-
er than “111”, then it indicates that the “Remote” Re-
ceiving Terminal has detected Framing or Parity bit
errors in the DS3 frames that it is receiving.
NOTE: For more information on FEBE (Far-End-Block
Error), please see Section _.
93