Teledyne LeCroy SDA III-CompleteLinQ - Manual (Page 23)

Operator's Manual
PLL Types
FC G OLDEN
FC Golden is the default selection and implements the golden PLL as defined in the Fibrechannel spec-
ification. By default, the golden PLL is set to a cutoff frequency of 1/1667 times the bit rate of the signal
under test. This ratio can be adjusted from 1/10 to 1/1e6.
Make the following settings for the FC Golden PLL on the Golden PLL dialog at the far right of the screen:
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Touch inside the Cutoff Divisorfield and enter a value using the pop-up keypad. The default value
of 1667 is the industry standard for a Golden PLL and equals the ratio of the Bit Rate to the PLL Cut-
off frequency.
The PLL cutoff divisor is the value by which the bit rate is divided to compute the cutoff frequency
for the loop bandwidth of the clock recovery operation for sequential eye pattern, jitter, and bit
error rate functions. This control is variable from 10 to 1,000. A low PLL cutoff divisor means the
PLL tracks and, therefore, attenuates jitter at higher frequencies.The default value of 1667 causes
the clock recovery to operate as a golden PLL, as defined in the Fibrechannel specification.
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The PLL Cutoff frequency control reads the frequency corresponding to the Cutoff Divisor. Alter-
natively, the PLL Cutoff frequency may be provided and the nearest cutoff divisor is then com-
puted from the entry.
PCI-E XPRESS
There are four PCI-Express selections that meet the following standards:
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PCI-Express Gen1
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PCI-Express Gen2 A
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PCI-Express Gen2 B
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PCI-Express Gen2 C
DVI
921143 Rev A 21