XRT72L53 Datasheet, PDF (119/467 Pages) Exar Corporation – THREE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

XRT72L53
REV. P1.1.7
THREE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
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PRELIMINARY
This Read/Write bit-field is used to configure the
Transmit Section of the Channel, to compute an insert
the BIP-4 value into each outbound E3 frame.
Setting this bit-field to "0", configures the Transmit
Section of the Channel to NOT compute and insert
the BIP-4 value into each outbound E3 frame. Instead
these four bits will contain data that has been input
via the Input Interface.
Setting this bit-field to "1", configures the Transmit
Section of the Channel to compute and insert the
BIP-4 value into each outbound E3 frame.
NOTE: For more information on these BIP-4 Calculations,
please see Section 4.2.4.2.2.
Bit 6, 5, TxASourceSel[1:0]
These two Read/Write bit-fields combine to specify
the source of the A-bit, within each outbound E3
frame. The relationship between these two bit-fields
and the resulting source of the A Bit is tabulated be-
low.
TXASOURCESEL[1:0]
SOURCE OF A BIT
00
TxE3 Service Bits Register (Address = 0x35)
01
Transmit Overhead Data Input Interface
10
Transmit Payload Data Input Interface
11
Functions as a FEBE (Far-End-Block Error) bit-field.
This bit-field is set to "0", if the Near-End Receive Section (within this chip) detects no BIP-4
Errors within the incoming E3 frames.
This bit-field is set to "1", if the Near-End Receive Section (within this chip) detects a BIP-4
Error within the incoming E3 frame.
NOTE: For more information on the A-bit, within the ITU-T
G.751 frame, please see Section 4.1.1.1.
Bits 4, 3, TxNSourceSel[1:0]
These two Read/Write bit-fields combine to specify
the source of the N-bit, within each outbound E3
frame. The relationship between these two bit-fields
and the resulting source of the N Bit is tabulated be-
low.
TXNSOURCESEL[1:0]
SOURCE OF N BIT
00
TxE3 Service Bits Register (Address = 0x35)
01
Transmit Overhead Data Input Interface
10
Transmit LAPD Controller
11
Transmit Payload Data Input Interface.
NOTE: For more information on the N-bit, within the ITU-T
G.751 frame, please see Section 4.1.1.2.
Bit 2 - TxAIS Enable
This Read/Write bit-field is used to configure the
Transmit Section of the Framer IC to transmit an AIS
pattern to the remote terminal
Setting this bit-field to "0" configures the Transmit
Section (of the chip) to transmit data in a normal man-
ner (e.g., as received via the Input Interface).
Setting this bit-field to "1" configures the Transmit
Section (of the chip) to transmit an "All Ones" pattern
(e.g., an AIS pattern) to the remote terminal.
NOTE: For more information on the AIS pattern, please see
Section 4.2.4.2.1.1.
Bit 1 - TxLOS Enable
This Read/Write bit-field is used to configure the
Transmit Section of the Framer IC to transmit an LOS
(e.g., All Zeros) pattern to the remote terminal
Setting this bit-field to "0" configures the Transmit
Section (of the chip) to transmit data in a normal man-
ner (e.g., as received via the Input Interface).
Setting this bit-field to "1" configures the Transmit
Section (of the chip) to transmit an "All Zeros" pattern
(e.g., an LOS pattern) to the remote terminal.
NOTE: For more information on the LOS pattern, please
see Section 4.2.4.2.1.2.
Bit 0 - TxFAS Source Select
This Read/Write bit-field is used to configure the
Transmit Section of the Channel to either:
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