XRT72L13 Datasheet, PDF (153/370 Pages) Exar Corporation – M13 MULTIPLEXER/CLEAR CHANNEL DS3 FRAMER IC

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PRELIMINARY
M13 MULTIPLEXER/CLEAR CHANNEL DS3 FRAMER IC XRT72L13
REV. 1.0.6
2.3.2.93 CP-Bit Error One Second Accumulator
Register - LSB
CP-BIT ERRORS - ONE SECOND ACCUMULATOR REGISTER - LSB (ADDRESS = 0X73)
BIT 7
RO
0
BIT 6
RO
0
BIT 5
RO
0
BIT 4
BIT 3
CP Bit Error Count - Low Byte
RO
RO
0
0
BIT 2
RO
0
BIT 1
RO
0
BIT 0
RO
0
This “Read-Only” register, along with the “Frame CP-
Bit Error - One Second Accumulator Register - MSB”
(Address = 0x72) contains a 16-bit representation of
the number of “CP Bit Errors” tjhat have been detect-
ed by the Receive DS3 Framer block, within the last
one-second sampling period. This register contains
the LSB (or Lower Byte) value of this 16-bit expres-
sion.
2.3.2.94 Line Interface Drive Register
LINE INTERFACE DRIVE REGISTER (ADDRESS = 0X80)
BIT 7
R/W
0
BIT 6
R/W
0
BIT 5
REQB
R/W
0
BIT 4
TAOS
R/W
0
BIT 3
ENCODIS
R/W
1
BIT 2
TxLEV
R/W
0
BIT 1
RLOOP
R/W
0
BIT 0
LLOOP
R/W
0
Bit 5 - REQB - (Receive Equalization Bypass Con-
trol)
This "Read/Write" bit-field allows the user to control
the state of the REQB output pin of the XRT72L13.
This output pin is intended to be connected to the
REQB input pins of the XRT7300 DS3/E3 LIU IC. If
the user forces this signal to toggle "high", then the
Receive Equalizer (within the XRT7300) will be dis-
abled. Conversely, if the user forces this signal to
toggle "low", then the Receive Equalizer (within the
XRT7300) will be enabled.
Writing a "1" to this bit-field causes the Framer device
to toggle the REQB output pin "high". Writing a "0" to
this bit-field causes the Framer device to toggle the
REQB output pin "low".
For information on the criteria that should be used
when deciding whether to bypass the equalization cir-
cuitry or not, please consult the "XRT7300 DS3/E3/
STS-1 LIU IC" data sheet.
NOTE: If the customer is not using the XRT7300 DS3/E3/
STS-1 LIU IC, then he/she can use this bit-field and the
REQB output pin for other purposes.
Bit 4 - TAOS - (Transmit All Ones Signal)
This "Read/Write" bit-field allows the user to control
the state of the TAOS output pin of the XRT72L13.
This output pin is intended to be connected to the
TAOS input pin of the XRT7300 DS3/E3/STS-1 LIU
IC. If the user forces this signal to toggle "high", then
the XRT7300 LIU device will transmit an "All Ones"
pattern onto the line. Conversely, if the user com-
mands this output signal to toggle "low" then the
XRT7300 LIU IC will proceed to transmit data based
upon the pattern that it receives via the TxPOS and
TxNEG output pins (of the Framer IC).
Writing a "1" to this bit-field will cause the TAOS out-
put pin to toggle "high". Writing a "0" to this bit-field
will cause this output pin to toggle "low".
NOTE: If the customer is not using the XRT7300 DS3/E3/
STS-1 LIU IC, then he/she can use this bit-field, and the
TAOS output pin for other purposes.
Bit 3 - Encodis - (B3ZS Encoder Disable)
This "Read/Write" bit-field allows the user to control
the state of the Encodis output pin of the XRT72L13
M13 device. This output pin is intended to be con-
nected to the Encodis input pin of the XRT7300 DS3/
E3/STS-1 LIU IC. If the user forces this signal to tog-
gle "high", then the "internal B3ZS/HDB3 encoder"
(within the XRT7300) will be disabled. Conversely, if
the user command this output signal to toggle "low",
then the "internal B3ZS/HDB3 encoder" (within the
XRT7300) will be enabled.
Writing a "1" to this bit-field causes the Framer IC to
toggle the "Encodis" output pin "high". Writing a "0"
to this bit-field will cause the Framer IC to toggle this
output pin "low".
NOTES:
1. The B3ZS/HDB3 encoder, within the XRT7300, is
not to be confused with the B3ZS/HDB3 encoding
capable that exists within the Transmit Section of
the Framer IC.
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