CAPSCam exposure sequence ========================= A. Exposure sequence start A1. Start timer0 B. FF exposure start B1. FF flush (2.2 sec) B2. FF reset-read (8.4 sec) B3. Busy-wait with timer0, round up to next 1 sec B4. Start timer1, open shutter (if GW not active) C. GW exposure start C1. GW flush (11 ms for 64x64) C2. GW reset-read (33 ms for 64x64) C3. Start timer2, open shutter D. GW exposure end D1. Expose/Wait until timer2 = GW exposure time D2. Stop timer2, close shutter (wait 50ms shutter to close) D3. GW line-by-line readout (33 ms) D4. Busy-wait with timer0, round up to next 100ms E. Repeat C+D for each GW exposure F. FF exposure end F1. Expose/Wait until timer1 = FF exposure time F2. Stop timer1, close shutter (if open) F3. FF line-by-line readout (8.4 sec) G. Exposure sequence end G1. Close shutter. Notes ----- [1] In this sequence, the shutter opens and closes for each GW exposure. [2] The flush timing for each row is 50 us + 2 us per pixel in the row (ie approx 1.08ms for FF row=512 pixels, 180us for GW row=64 pixels). The flush is done row-by-row and consists of a line reset (50us), followed by a fast pseudo-read (2 us) of each pixel in the row. [3] The readout timing is 8 us per pixel. In FF mode, there are 4 output amps, so each readout stripe consists of 2048x512 pixels. In GW mode, there is only one output amp. For the FF readout, pixel (1,1) is read 8.4 seconds before pixel (512,2048). [4] There are three timers used, all with 1ms resolution. Timer 1 is the FF exposure timer. Timer 2 is the GW exposure timer. Timer 0 is used by the dsp (in the detector electronics) to synchronize the exposure sequence(s) with the linux data acquisition computer, so that the linux computer knows when the next batch of data is on its way. The initial FF reset-read is rounded up to the next second, and each GW sequence is rounded up to the next 100ms.