XRT72L53 Datasheet, PDF (111/467 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 byte-fields is used to specify the
contents of the MA byte-field in each outbound E3
frame.
NOTE: The values written into bit-fields 6 (FEBE) and 7
(FERF) are inserted into outbound E3 frames, only if bit-
field 0 (MAx) within the Tx E3 Configuration Register
(Address = 0x28) is set to "0". Otherwise, the Transmit DS3/
E3 Framer block will set the FERF and FEBE values, within
each outbound E3 frame, to values based upon Receive
DS3/E3 Framer block conditions.
2.4.6.5.2 The October 1998 Revision
If the channel has been configured to support the Oc-
tober 1998 revision of the ITU-T G.832 framing format
for E3; then the bit-format of the TxE3 MA Byte regis-
ter is as presented below.
TXE3 MA BYTE REGISTER (ADDRESS = 0X36)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
Transmit MA Byte
FERF
FEBE
Payload Type
R/W
R/W
R/W
R/W
R/W
0
0
0
1
0
BIT 2
BIT 1
MFI[1:0]
R/W
R/W
0
0
BIT 0
SSM
R/W
0
This Read/Write byte-fields is used to specify the
contents of the MA byte-field in each outbound E3
frame.
NOTE: The values written into bit-fields 6 (FEBE) and 7
(FERF) are inserted into outbound E3 frames, only if bit-
field 0 (MAx) within the Tx E3 Configuration Register
(Address = 0x28) is set to "0". Otherwise, the Transmit DS3/
E3 Framer block will set the FERF and FEBE values, within
each outbound E3 frame, to values based upon Receive
DS3/E3 Framer block conditions.
2.4.6.6 Transmit E3 NR Byte Register (E3, ITU-
T G.832)
TXE3 NR BYTE REGISTER (ADDRESS = 0X37)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
TxNR[7:0]
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
1
0
0
0
0
This Read/Write byte-field is used to specify the con-
tents of the NR byte-field in each outbound E3 frame.
NOTE: The contents of this register is ignored, if the LAPD
Transmitter is enabled and has been configured to insert
the comprising octets of an outbound LAPD Message
frame into the NR byte-field of each outbound E3 frame
(e.g., if DLinNR = "1").
2.4.6.7 Transmit E3 TTB-0 Register (E3, ITU-T
G.832)
TXE3 TTB-0 REGISTER (ADDRESS = 0X38)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
TxTTB0[7:0]
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
1
0
0
1
0
0
0
0
This Read/Write byte-field, along with the Tx TTB-1
through Tx TTB-15 registers permit a user to define a
Trail Access Point Identifier sequence of bytes, that
will be transmitted to the Remote Terminal. The Re-
mote Receiving Terminal will use this sequence of
bytes to verify that it is connected to the proper Trans-
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