Altera JNEye User Manual
Page 18
Option 1 configures the reference clock with the following options:
• Random Jitter— Specify the frequency range (in ps).
Note: Altera recommends that the maximum frequency range (f
MAX
) of the phase noise be set to the
reference clock frequency. If the f
MAX
is less than the reference clock frequency, JNEye uses
linear extrapolation to calculate the phase noise at f
MAX
, which can lead to inaccurate results.
• Periodic Jitter Type—Specify the shape profile, frequency (in Hz), and amplitude (in ps). The shape
profile can be:
• Triangle
• Hershey with programmable Hershey shape parameter
• Sharkfin with programmable Sharkfin shape parameter
• Sinusoidal
• Spurs—Specify clock spectrum spurs with individual frequency (in Hz) and amplitude (in dBc). For
example, if the reference clock has three spurs: –110 dBc at 100 KHz, –90 dBc at 1 MHz, and –80 dBc
at 10 MHz, you can input the following text into the Spurs text box:
100e3 -110
1e6 -90
10e6 -80
• Spur Phase Offset
Use the Spur Phase Offset pull-down menu to configure the initial phase of spur noises. The options
are:
• Auto—JNEye automatically selects the default initial spur noise phase. The default initial spur
phase is 0 rad.
• Random—JNEye randomly sets the initial spur noise phases.
• Zero—JNEye sets the initial spur noise phase to 0 rad.
• Specified—You can manually specify the initial spur phase individually by adding the phase value
after the amplitude value. The following example shows the initial spur noise phases are 1.0, 2.0,
and 3.0 rad.
100e3 -110 1.0
1e6 -90 2.0
10e6 -80 3.0
2-12
Link and Simulation Setting
UG-1146
2015.05.04
Altera Corporation
Functional Description