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2.1.2 Pedestals & Sigmas

  Pedestals are kept at Memory address $0040'0000. 32-bit words are being used, and blocks of (1280 strips 8 FADCs) words are stored for 32 Pipeline Buffers consecutively.

$0040'0000: PIC 0, FADC 0
&vdots; &vdots;
$0040'1400: PIC 0, FADC 1
&vdots; &vdots;
&vdots; &vdots;
$0040'A000: PIC 1, FADC 0

In contrast to the Raw data order, the pedestal words for every FADC are stored sequentially, i.e. each FADC has its `own' coherent memory block. The total size of the Pedestal Block is 4 &sp; bytes 10240 &sp; strips 32 &sp; Pipeline Buffers = 1280 &sp;kBytes.

Sigmas are kept at Memory address $0020'0000. Rather than keeping just the rms noise sigma, a quadruple is stored for each strip:

( Variance, Pulse Height Sum, Pulse Height Sum Squared, Counts).

Each of the words is 32-bit, so that the total size of the ``Sigma Block'' is 4 &sp; bytes 4 &sp; words 10240 &sp; strips = 160 &sp; kBytes.



Markus Kausch
Fri Oct 17 13:45:07 MST 1997