Date: 0ct 17, 2013
Subject: Spex (sparc,ixthos) dsp timing and slow counts, and pixel rates
1. guidedog
Table of slowcnt, pixel_reate, and Frame_rate....
slowcnt Clock_nsec clock_between pixel_rate Frame_rate
samples usec msec
fastmd 125 15 1.875 65.495
3 225 15 3.375 117.882
4 250 15 3.750 130.952
5 275 15 4.125 144.022
10 400 15 6.000 209.369
20 650 15 9.750 340.064
Notes:
Slowcnt is a user parameter to slow down the clocking of the waveforms.
The default for guidedog and bigdog are 20 (as of oct 17, 2013).
Clock_nsec = 150 + slow_cnt*25
Clock_between_sample = there are 15 clocks between each 8 channel convert/sample.
Pixel_rate_usec = clock_nsec x 15
Frame_rate_msec in the table is measured from guidedog.
Frame_rate_msec (est) = pixel_rate * 512row * (512col/8ch) * 1.0644(add 6.44% overhead ) * 0.001(usec2msec)
pixel_rate * 512 * 64 * 1.0644 * 0.001
2. bigdog
Bigdog is similar except that there are 23 clocks between sample (vs 15 for guidedog).
For Bigdog, I only measured 05, 10, and 20 slow counts.
slowcnt Clock_nsec clock_between pixel_rate Frame_rate
samples usec msec
5 275 23 6.325 216.955
10 400 23 9.200 315.454
20 650 23 14.950 512.452
Frame_rame is meaused from bigdog.
me_rate_msec (est) = pixel_rate * 512row * (512col/8ch) * 1.0644(add 4.6% overhead ) * 0.001(usec2msec)
pixel_rate * 512 * 64 * 1.046 * 0.001
References
Saved some FITS files and DSPTiming files for Guidedog, Bigdog here
in bigdog_data_timing/ and guidedog_data_timing/.