XRT72L13 Datasheet, PDF (252/370 Pages) Exar Corporation – M13 MULTIPLEXER/CLEAR CHANNEL DS3 FRAMER IC

XRT72L13
M13 MULTIPLEXER/CLEAR CHANNEL DS3 FRAMER IC
REV. P1.0.6
áç
PRELIMINARY
OPERATING MODE REGISTER (ADDRESS = 0X00)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT2
BIT 1
BIT 0
Local Loop-
back
Mode
Line Loop-
back
Mode
Internal LOS
Enable
RESET
R/W
R/W
R/W
R/W
0
0
1
0
3. Interface the XRT72L13, to the Terminal Equip-
ment, as illustrated in Figure 65 .
4.2.1.3 Mode 3 - The "Serial/Local-Timed/
Frame-Master" Mode
Behavior of the XRT72L13
If the XRT72L13 has been configured to operate in
this mode, then the XRT72L13 will function as fol-
lows.
A. Local Timing - (Uses the "TxInClk" signal as
the Timing Reference)
In this mode, the Transmit Section of the XRT72L13
will use the "TxInClk" signal as its timing reference.
B. Serial Mode
The XRT72L13 will receive the DS3 payload data, in
a serial manner, via the "TxSer" input pin. The
"Transmit Payload Data Input Interface" (within the
XRT72L13) will latch this data into its circuitry, on the
rising edge of the "TxInClk" input clock signal.
Interrupt
Enable
Reset
Frame Format
TimRefSel[1:0]
R/W
R/W
R/W
R/W
1
0
0
1
C. Delineation of "outbound" DS3 frames (Frame
Master Mode)
The Transmit Section of the XRT72L13 will use the
"TxInClk" signal as its timing reference, and will ini-
tiate DS3 frame generation, asynchronously with re-
spect to any externally applied signal. The
XRT72L13 will pulse its "TxFrame" output pin "high"
whenever its it processing the very last bit-field within
a given DS3 frame.
D. Sampling of payload data, from the Terminal
Equipment
In Mode 3, the XRT72L13 will sample the data, at the
"TxSer" input pin, on the rising edge of "TxInClk".
Interfacing the "Transmit Payload Data Input In-
terface" block (of the XRT72L13) to the Terminal
Equipment for Mode 3 Operation
Figure 67 presents an illustration of the "Transmit
Payload Data Input Interface" block (within the
XRT72L13) being interfaced to the Terminal Equip-
ment, for "Mode 3" operation.
240