Changes between Version 1 and Version 2 of UfoCameraOperation

Timestamp:

Mar 30, 2015, 12:04:26 PM (11 years ago)

Author:

Suren A. Chilingaryan

Comment:

--

UfoCameraOperation

@@ -4 +4 @@
  * The bellow is explained how long it takes to read frame by hardware. We also need to add DMA timeout + PCIe transfer time on top of that before we can expect to acquire frame
 {{{
-Full readout time = exposure time + fot + readout time
-FOT = (reg73 + 2*(16/number_outputs))*129*clk_per
+ð  Yes, I wish to fix this definitively. We can assume for today and for the future that we want to use only microsecond time (not nanosecond) in the follows way:  total time = integration time + readout time + back pressure from PC/DMA
 
-Readout time = (129 * clk_per * 16/number_outputs) * num_lines,
+ð  Integration time  à set by  Libuca so that you know well (microsecond)
 
-where:
+ð  Readout time = number of rows * time per row. Now, number of rows à set by Libuca (you know) and the time per row is:
 
-reg73= 7 (I think, just check this)
-number_outputs = 16 -for 10bit, 4 - for 12bit
-clk_per=25ns
-num_lines = 1088 or 2047 or 1, depends what you set....
+o   = 13us for 4MPixel @ 11 or 12 bit
+
+o   = 3.3us for 4MPixel @ 10 bit
+
+o   = 2.7us for 2MPixel @ clock 48MHz (in this case only 10bit is available)
+
+ð  back pressure from PC/DMA à this is very variable and depends from the PC status not from the electronics.
+
+ð  The DMA timeout is  67 ms that is too much. What we can do easily is to bring this timeout programmable by software, we will create a new register in the DMA bank register (address 0x64-0x68), so that you can define your timeout.
 }}}