JAI AT-140GE - Manual (Page 22)

AT-140GE
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Start Point
End Point
Length
Start Point
End Point
Length
7.4.3 Pulse generators (20-bit x 2)
There are 2 pulse generators (designated 0 through 1) that can be used to create various
timing scenarios by programming start point, endpoint, length and repeats.
An example of settings
The following example shows the FVAL input to a pulse generator. The pulse generator
creates the pulse using FVAL and the pulse is output through GPIO PORT 1.
Fig.17 Pulse generator setting example
The created pulse rises up at the start point and falls down at the end point, as shown above.
Accordingly, the High duration is (End point – Start point) clocks x (1/Pulse gen. frequency).
In the above example, the original oscillation uses pixel clock (60 MHz) and the pixel clock is
divided by 2400. A pulse frequency of the generator is 25 KHz (60000000/2400). As the start
point is 0 and the end point is 99, a pulse having a width of 100 x 1/25000 = 4ms is created.
If the High duration needs to be delayed against an incoming trigger, the start point should be
set at “N”. The delay value is N x (1/ 25000). In the above example, the N is “0” which is no
delay. The length, in this case, is 102 clocks.
These settings can be achieved by using the JAI Control Tool which is part of the JAI SDK.
Pulse Generator 0 IN
(FVAL )
0 1 2 3
1
99 100 101 102 103
2 1
Start Point = 0 End Point = 99
Length = 102
Clock IN
Clock Source=Pixel Clock ( 60MHz)
Clock Pre-scaler = 2399 ⇒ 25KHz
1/25KHz = 40µs
Pulse Generator Clear = 4: Rising Edge
Pulse Generator 0 OUT
(GPIO Port 1 )
Repeat counter: 0 to 255
=0: Continuously repeated
Pulse Generator Setting Example