The calibration system software includes code, to be run on some on-line host, to calculate gain averages and widths for every anodes based on charge injection on all wafer at precise location.
The gains are an essential component of the analysis. They should in principle be constant. Variations of the gain might result from electronics gain variation in particular and must therefore be kept track of.
The calibration system software includes code to translate the gain averages measured by charge injection into gain look-up tables to be down-loaded into the ASICs memories.
Gain corrections are performed in a distributed fashion by the ASICs so that the data sent to the trigger have a straightforward interpretation. The mechanism for gain correction is based on fast lookup tables. These tables are obtained from a desired gain function taking into account the known non-linearities of the electronics, the bit reduction/compression (10 bits to 8 bits mapping) and the gain measured by charge injection.