PM73121ꢀAAL1gator II
Data Sheet
PMC-Sierra, Inc.
PMC-980620
,VVXHꢀꢁ
AAL1 SAR Processor
8.10.3 SRTS T1 Clock
20
The T1 SRTS clock jitter was measured using a 2 -1 PRBS pattern in unstructured mode.
Two AAL1gator IIs were connected to each other across a point to point ATM connection. One
AAL1gator II was used to generate SRTS values, and the other AAL1gator II was used to receive
the values. The source AAL1gator II was connected to a FIREBERD, which used an external
signal generator as its clock source. The clock source was stepped across the entire ± 200 ppm
range and the jitter was measured at the FIREBERD connected to the AAL1gator II at the
receiving end. A jitter spectrum was then taken at the frequency that exhibited the worst jitter.
The total maximum jitter without the jitter attenuator was 1.91 UI. With a jitter attenuator the
maximum jitter was 0.26 UI, other than a spike at - 200 ppm. See Figure 100 through Figure 103
on page 190 for jitter versus frequency and the jitter spectrum versus the G.824 mask.
2.5
2
1.5
SRTS
1
0.5
0
1543600 1543800 1544000 1544200 1544400
Frequency +/- 200 ppm
Figure 100. Maximum T1 SRTS Jitter with no Jitter Attenuator
ꢀꢇꢇ
PMC [ PMC-SIERRA, INC ]
