XRT72L13 Datasheet, PDF (356/370 Pages) Exar Corporation – M13 MULTIPLEXER/CLEAR CHANNEL DS3 FRAMER IC

XRT72L13
M13 MULTIPLEXER/CLEAR CHANNEL DS3 FRAMER IC
REV. P1.0.6
áç
PRELIMINARY
either the DS1, the E1 (or ITU-T G.747) or the “DS2
Pass-Thru” Modes.
5.2.1.1.1.1 Configuring M12 MUX # 1 into the
DS1 Mode
The user can configure M12 MUX # 1 to operate in
the “DS1” Mode by setting Bits 4 (M12 G.747) and 5
(M12 By-Pass) to “0”, within the “M12 DS2 # 1 Con-
figuration” 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
0
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
DS1” Mode. When M12 MUX # 1 is operating in the
“DS1” Mode, then it will be configured to accept four
(4) DS1 signals (via the “TxDS1Data_0” through
“TxDS1Data_3” input pin) and generate a DS2 signal.
M12 MUX # 1 will use the rising edges of
“TxDS1Clk_0” through “TxDS1Clk_3” in order to latch
the contents of the “TxDS1Data[3:0] inputs into the
M12 MUX # 1 circuitry.
NOTE: Once the user configures M12 MUX #1 to operate in
the “DS1” Mode, M12 DEMUX # 1 will also be configured to
operate in the “DS1” Mode.
Figure 120 presents a simple illustration of M12 MUX
# 1 (which has been configured to operate in the
“DS1” Mode), accepting the four DS1 signals, along
with their corresponding clock signals.
FIGURE 120. ILLUSTRATION OF M12 MUX #1 BEING CONFIGURED TO OPERATE IN THE “DS1” MODE
DS1 Channel 1
DS1 Channel 2
DS1 Channel 3
DS1 Channel 4
M12
MUX
DS2 Channel
As M12 MUX # 1 accepts these four (4) DS1 signals, multiplexing each of these composite DS1 signals.
it will form a “DS2” signal, by performing “bit-wise”
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