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DLPC350: dlpc350/LightCrafter 4500 incorrect exposure generation in variable exposure mode

Part Number: DLPC350
Other Parts Discussed in Thread: DLP4500

Hi all,

I have a design with dlpc350 and can connect to it via LightCrafter 4500 USB. I am going to work with VSYNC and use dlpc in variable expo mode. So, I am generation VSYNC and required signals - HSYNC, VSYNC - on video port. Here is the specification of VSYNC period: 12.190 ms. I am going to have 8-bit patterns - that I put them into one VSYNC -  and two 1-Bit patterns with half of period of VSYNC - 12.19/2=6.095 us - and put every two in one VSYNC.

8-Bit patterns: expo=10ms, period=12.19 ms

1-Bit patterns: expo=1ms, period=6.095ms

Below picture shows it:

For some TRIG_OUT1 pulses  there are spikes!. and also some exposures - TRIG_OUT1 - don't seem to be exactly the exposure I have given in software. Like below picture for 1-Bit patterns that it is not exactly 1 ms or it has pulses

In above captured signal it shows after VSYNC TRIG_OUT1 expo! The problem is that spike in the beginning. And, there are still some other TRIG_OUT1 pulses that don't have spike, but the width of them is not actually 1ms it is more. It seems that LightCrafter or dlpc350 itself couldn't generate such exposure. This happens for other VSYNC periods as well. I think it i not related to the VSYNC period.

I have to add that I am working in mode 0 which means sending patterns starts upon software request not with TRIG_IN1 or TRIG_IN2. Do I have to work in mode 1 for variable exposure mode?

I would appreciate any help on this issue.