XRT7250 Datasheet, PDF (109/463 Pages) Exar Corporation – DS3/E3 FRAMER IC

XRT7250 DS3/E3 FRAMER IC
REV. 1.1.1
áç
TXDS3 F-BIT MASK REGISTER - 4 (ADDRESS = 0X39)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
FBit Mask[7] FBit Mask[6] FBit Mask[5] FBit Mask[4] FBit Mask[3] FBit Mask[2] FBit Mask[1] FBit Mask[0]
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
0
Bits 7 - 0 F-Bit Mask[7:0]
These Read/Write bit-fields allow the user to insert
errors into the last eight F-bits of a DS3 M-frame, for
test and diagnostic purposes. The Transmit DS3
Framer block automatically performs an XOR opera-
tion on the actual contents of these F-bit fields to
these register bit-fields. Therefore, for every "1" that
exists in these bit-fields, this will result in a change of
state for the corresponding F-bit, prior to being trans-
mitted to the Remote Terminal Equipment.
If the Transmit DS3 Framer block is to be operated in
the normal mode (e.g., when no errors are being in-
jected into these F-bit fields of the outbound DS3
frames), then all of these bit-fields must be "0’s".
2.3.6 Transmit E3 (ITU-T G.832) Configuration
Registers
2.3.6.1 Transmit E3 Configuration Register
(E3, ITU-T G.832)
TXE3 CONFIGURATION REGISTER (ADDRESS = 0X30)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Not Used
TxDL
in NR
Not Used
TxAIS
Enable
TxLOS
Enable
TxMARx
RO
RO
RO
R/W
RO
R/W
R/W
R/W
0
0
0
0
0
0
0
0
Bit 4 - DLinNR
This Read/Write bit-field allows the user to specify
whether the LAPD Transmitter should insert the out-
bound LAPD Message frame octets into the NR byte-
field, or in the GC-byte-field, within each outbound E3
frame.
Writing a "1" configures the LAPD Transmitter to in-
sert the octets of the outbound LAPD Message frame
into the NR byte-field, within each outbound E3
frame. Writing in "0" configures the LAPD Transmitter
to insert the octets of the outbound LAPD Message
frame into the GC byte-field, within each outbound E3
frame.
Bit 2 - TxAIS Enable
This Read/Write bit-field allows the user to command
the Transmit E3 Framer to transmit an AIS pattern,
upon demand.
Writing a "0" to this bit-field allows the Transmit E3
Framer to transmit internally generated data (e.g., the
ITU-T G.832 compatible E3 frames with the E3 pay-
load data) to the Remote Terminal. Writing a "1" to
this bit-field causes the Transmit E3 Framer to trans-
mit an all "1’s" pattern to the Remote Terminal.
NOTE: If the Transmit E3 Framer is transmitting an AIS pat-
tern to the Remote Terminal, then it is not transmitting any
E3 frames or ATM cell data. Consequently, if this command
is invoked, the Remote Terminal will experience an OOF
(Out of Frame) condition.
Bit 1 - TxLOS Enable
This Read/Write bit-field allows the user to command
the Transmit E3 Framer to transmit an LOS pattern,
upon demand.
Writing a "0" to this bit-field allows the Transmit E3
Framer to transmit internally generated data (e.g., the
ITU-T G.832 compatible E3 frames with ATM cell da-
ta) to the Remote Terminal. Writing a "1" to this bit-
field causes the Transmit E3 Framer to transmit an
"All 0’s" pattern to the Remote Terminal.
NOTE: If the Transmit E3 Framer is transmitting an LOS
pattern to the Far-End Terminal, then it is not transmitting
any E3 frames or ATM cell data. Consequently, the Far-End
Terminal will experience an LOS (Loss of Signal) and OOF
(Out of Frame) condition.
Bit 0 - MARx (FERF and FEBE bit-field Loopback)
This Read/Write bit-field allows the user to specify
whether the value of the FERF and FEBE bit-fields, in
the outbound E3 frames, should be based upon Re-
90