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FALC
56
PEF 2256 H/E
Functional Description T1/J1
User’s Manual
Hardware Description
133
DS1.1, 2003-10-23
5.1.12
According to the input jitter defined by PUB62411 the FALC
56 generates the output
jitter which is specified in
Table 30
below.
Output Jitter (T1/J1)
5.1.13
Framer/Synchronizer (T1/J1)
The following functions are performed:
Synchronization on pulse frame and multiframe
Error indication when synchronization is lost. In this case, AIS is sent to the system
side automatically and remote alarm to the remote end if enabled.
Initiating and controlling of resynchronization after reaching the asynchronous state.
This is done automatically by the FALC
56 or user controlled by the microprocessor
interface.
Detection of remote alarm (yellow alarm) indication from the incoming data stream.
Separation of service bits and data link bits. This information is stored in special
status registers.
Detection of framed or unframed in-band loop-up/-down code
Generation of various maskable interrupt statuses of the receiver functions.
Generation of control signals to synchronize the CRC checker, and the receive
elastic buffer.
If programmed and applicable to the selected multiframe format, CRC checking of the
incoming data stream is done by generating check bits for a CRC multiframe according
to the CRC6 procedure (as defined in ITU-T G.704). These bits are compared with those
check bits that are received during the next CRC multiframe. If there is at least one
mismatch, the 16-bit CRC error counter is incremented.
5.1.14
Receive Elastic Buffer (T1/J1)
The received bit stream is stored in the receive elastic buffer. The memory is organized
as a two-frame elastic buffer with a maximum size of 2
×
193 bit. The size of the elastic
buffer is configured independently for the receive and transmit direction. Programming
of the receive buffer size is done by SIC1.RBS1/0:
Table 30
Specification
Output Jitter (T1/J1)
Measurement Filter Bandwidth
Lower Cutoff
10 Hz
8 kHz
10 Hz
Broadband
Output Jitter
(UI peak to peak)
Upper Cutoff
8 kHz
40 kHz
40 kHz
PUB 62411
< 0.015
< 0.015
< 0.015
< 0.02