E2v ELIIXA+ 16K/8K CXP MONO User Manual - page 31
U
SER
M
ANUAL
ELIIXA+
16
K
/8
K
CXP
M
ONO
–
R
EV
K
–
06/2017
P
A G E
|
31
7.3.7 Rescaler
Feature Name
CXP @
Size
bytes
R/W Bit field Description
TriggerRescalerSource
0x08540
4
RW [31-30] RescalerSize (see 7.3.7)
Bit0:
0: line0 selected for rescaler
1: line1 selected for rescaler
Bit1: Bypass Rescaler
TriggerRescalerMultplier
RW [29-18] mult factor for rescaler function
Rescaler will create "mult" pulse between
input trig
TriggerRescalerDivider
RW
[17-6] div factor for rescaler function
Rescaler will take 1 pulse each "div" pulse
TriggerRescalerGranularity
RW
[5-4]
0: 1 *20 = 20 ns
1: 4 *20 = 80 ns
2: 16 *20 = 320 ns
3: 256 *20 = 5120 ns
TriggerRescalerCountInt
0x08544
RO
[31-16] count_int counter of rescaler bloc
count between 2 input trig
TriggerRescalerCountIntOverflow
RO
[15]
count_int Overflow
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.
Trigger
Divider
Multiplier
Trigger
Rescaler
samples
20ns x granularity
MaxSampledPeriod