® 16k/8k CXP Color
26
e2v semiconductors SAS 2014
Rescaler
Feature Name
Description
TriggerRescalerSource
Selection of the input source of the Rescaler :
- Line0
- Line1
- Bypass Rescaler
TriggerRescalerMultplier
Multiplier factor :
1 to 4096
TriggerRescalerDivider
Divider factor :
1 to 4096
TriggerRescalerGranularity
- 20 ns
- 80 ns
- 320 ns
- 5120 ns
TriggerRescalerCountInt
count_int overflow
TriggerRescalerCountIntOverflow
count_int counter of rescaler bloc
count between 2 input trig
6.2.3.4
Rescaler
The camera has two registers per line which can define a rescaler: a multiplier and a divider.
With these two registers, the end-user can change the frequency of the line.
The generated line has always a 50% duty cycle. With the combination of a multiplier and divider, the system can
generate any frequency
The system must sample the input signal to compute its frequency.
Two parameters define the sample settings:
-
RescalerSize
-
Granularity
The Rescaler Size defines the maximum number of samples. Two values are possible: 12bit (4096 samples) or 16bit
(65536 samples).
The Granularity allows the rescaler to generate the sample periodicity. Four values are possible: 1, 4, 16 or 256
system clock cycles.
The system clock period is 20ns. So the time between samples is (Granularity x 20ns)
With these two parameters, the user must determine the best sample range. It is the user responsibility to configure
the rescaler.
The MaxSampledPeriod must be as close as possible to the trigger period while still being longer
MaxSampledPeriod = 20ns x granularity x 2
rescalerSize
The array below gives the MaxSampledPeriod in millisecond
Trigger
Divider
Multiplier
Trigger
Rescaler
samples
20ns x granularity
MaxSampledPeriod
