XRT72L13 Datasheet, PDF (268/370 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
TABLE 15: THE RELATIONSHIP BETWEEN THE NUMBER OF RISING CLOCK EDGES IN TXOHCLK, (SINCE
"TXOHFRAME" WAS LAST SAMPLED "HIGH") TO THE DS3 OVERHEAD BIT, THAT IS BEING PROCESSED
NUMBER OF RISING CLOCK EDGES IN
TXOHCLK
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
THE OVERHEAD BIT EXPECTED BY THE
"XRT72L13"
FEBE
F1
M0
F1
DL
F0
DL
F0
DL
F1
M1
F1
UDL
FO
UDL
FO
UDL
F1
M0
F1
UDL
F0
UDL
F0
UDL
F1
CAN THIS OVERHEAD BIT BE ACCEPTED
BY THE XRT72L13?
Yes
No
No
No
Yes
No
Yes
No
Yes
No
No
No
Yes
No
Yes
No
Yes
No
No
No
Yes
No
Yes
No
Yes
No
3. After the Terminal Equipment has waited the
appropriate number of clock edges (from the
"TxOHFrame" signal being sampled "high"), it
should assert the "TxOHIns" input signal. Con-
currently, the Terminal Equipment should also
place the appropriate value (of the inserted over-
head bit) onto the "TxOH" signal.
4. The Terminal Equipment should hold both the
"TxOHIns" input pin "high" and the value of the
"TxOH" signal, stable until the next rising edge of
"TxOHClk" is detected.
Case Study: The Terminal Equipment intends to
insert the appropriate overhead bits into the
"Transmit Overhead Data Input Interface" (using
256