XRT72L56 Datasheet, PDF (349/486 Pages) Exar Corporation – SIX CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

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PRELIMINARY
XRT72L56
SIX CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
REV. P1.1.2
FIGURE 146. ILLUSTRATION OF THE SIGNALS THAT ARE OUTPUT VIA THE RECEIVE OVERHEAD OUTPUT INTERFACE
(FOR METHOD 1).
RxOHClk
RxOHFrame
RxOH
FAS, Bit 9
FAS, Bit 8
FAS, Bit 7
FAS, Bit 6
FAS, Bit 5
Terminal Equipment should sample
the “RxOHFrame” and “RxOH” signals
here.
Recommended Sampling Edges
Method 2 - Using RxOutClk and the RxOHEnable
signals
Method 1 requires that the Terminal Equipment be
able to handle an additional clock signal, RxOHClk.
However, there may be a situation in which the Termi-
nal Equipment circuitry does not have the means to
deal with this extra clock signal, in order to use the
Receive Overhead Data Output Interface. Method 2
involves the use of the following signals.
• RxOH
• RxOutClk
• RxOHEnable
• RxOHFrame
Each of these signals are listed and described below
in Table 66.
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