PM4314 QDSX
DATA SHEET
PMC-950857
ISSUE 5
QUAD T1/E1 LINE INTERFACE DEVICE
Example 2 shows a DSX 1/0 Cross-Connect using a PM4314 QDSX, a PM4344
TQUAD, and a Digital Time/Space Switch to implement a simple 1/0 cross-
connect. An alternate architecture could use two Digital Time/Space Switches,
one as a voice switch and the other as a signaling switch, and 2 TQUADs to
cross-connect eight T1s. (Note: a true implementation would require redundancy
in the switch core.)
In this example, the TQUAD is programmed to receive and generate the same
framing format, using the 2.048 MHz backplane data rate. The "system frame
pulse" signal is stretched through the two D-FF into a pulse of 488ns duration,
which is used to frame align the data out of each framer through the elastic store
and to provide frame alignment indication to the transmitters. The raw system
frame pulse signal is used to indicate frame alignment synchronization to the
Digital Time/Space Switch. Another D-FF is configured as a toggle to generate a
2.048MHz clock from the system 4.096MHz clock source, synchronized to the
system frame pulse. The TQUAD is configured to accept and source unipolar
signal from and to the QDSX. As shown, the jitter attenuation is performed in the
QDSX and is disabled in the TQUAD.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
11
PMC [ PMC-SIERRA, INC ]
