XRT72L13 Datasheet, PDF (360/370 Pages) Exar Corporation – M13 MULTIPLEXER/CLEAR CHANNEL DS3 FRAMER IC

XRT72L13
M13 MULTIPLEXER/CLEAR CHANNEL DS3 FRAMER IC
REV. P1.0.6
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PRELIMINARY
5.2.1.1.2 E1 (ITU-T G.747) Operation of the M12
MUX
This section discusses the various configuration op-
tions and features that are available whenever the
XRT72L13 has been configured to operate in the
“ITU-T G.747” Mode.
5.2.1.1.2.1 Configuring M12 MUX # 1 into the
“ITU-T G.747” Mode
The user can configure M12 MUX # 1 to operate in
the “ITU-T G.747” Mode by setting Bit 4 (M12 G.747)
to “1” and Bit 5 (M12 By-Pass) to “0”, within the “M12
DS2 # 1 Configuration” Register, as illustrated below.
M12 DS2 # 1 CONFIGURATION REGISTER (ADDRESS = 0X1A)
BIT 7
Reserved
7
R/W
X
BIT 6
Reserved
6
R/W
X
BIT 5
M12
Bypass
R/W
0
BIT 4
M12
G.747
R/W
1
BIT 3
M12
G.747 Res
R/W
X
BIT 2
M12 FERF
R/W
X
BIT 1
BIT 0
M12LBCode[1:0]
R/W
R/W
X
X
Once the user implements this configuration setting
then M12 MUX # 1 will be configured to operate in the
“ITU-T G.747” Mode. When M12 MUX # 1 is operat-
ing in the “ITU-T G.747” Mode, then it will be config-
ured to accept three (3) E1 signals (via the
“TxDS1Data_0” through “TxDS1Data_2” input pins)
and generate a “G.747” data stream. M12 MUX # 1
will use the rising edges of “TxDS1Clk_0” through
“TxDS1Clk_2” in order to latch the contents of the
“TxDS1Data[2:0]” inputs into the “M12 MUX # 1” cir-
cuitry.
Figure 123 presents an illustration of M12 MUX # 1
(which has been configured to operate in the “G.747”
Mode, accepting the three E1 signals, along with their
corresponding clock signals.
FIGURE 123. ILLUSTRATION OF THE M12 MUX # 1 BEING CONFIGURED TO OPERATE IN THE “G.747” MODE
E1 Channel 1
E1 Channel 2
E1 Channel 3
M12
MUX
G.747 Channel
As M12 MUX # 1 accepts these three (3) E1 signals, wise” multiplexing of the E1 signals. As M12 MUX # 1
it will form a “G.747” data stream, by performing “bit-
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