Alkeria NECTA Series - PLL Boundaries Readout; PLL Configuration; Trigger Manager

4. Interfacing to the world 60
The maximum allowed input jitter, expressed as the maximum absolute variation of the input period, is:
1
f
i
· M
(4.3)
while the maximum absolute jitter of the trigger output is not greater than 21 ns.
Note
Jitter in frequency input signals or encoder rotational affects the output trig-
ger, resulting in erratical acquisition cadence. Minimize input jitter in your ap-
plication for optimum performance.
The following code selects the source for the frequency multiplier and the multiplying factor:
Example Code 4.6 | PLL conguration
device.PLL.Source = PLLSource.External; // Select I/O port 0 as PLL source
device.PLL.ExternalInput = 0;
device.PLL.Multiplier = 10; // Set multiplier factor to 10 / 3
device.PLL.Divisor = 3;
device.FrameStartTrigger.Source = TriggerSource.PLL; // Set PLL as trigger source
device.FrameStartTrigger.Enable = true; // Enable Frame Start Trigger
The maximum and minimum allowed values for M and D can be retrieved by reading the following prop-
erties:
Example Code 4.7 | PLL boundaries readout
uint maxM = device.PLL.MaxMultiplier;
uint minM = device.PLL.MinMultiplier;
uint maxD = device.PLL.MaxDivisor;
uint minD = device.PLL.MinDivisor;
4.4.3 Trigger manager
The signal incoming from an input port can be also simply routed to the trigger manager. Every signal can
one the events listed below:
• Acquisition-start;
• Frame-start;
• Line-start;
• End-of-exposure.
For further information refer to Chapter 6.