Double Sample Conversion

Double sampling is enabled by setting the DSEN bit. When this bit is set, two conversions are required before the module calculates the threshold error. Each conversion must be triggered separately when CONT = 0, but will repeat automatically form a single trigger when CONT = 1. The first conversion will set the MATH bit and update the ADACC register, but will not calculate ADERR or trigger ADTIF. When the second conversion completes, the first value is transferred to ADPREV (depending on the setting of PSIS) and the value of the second conversion is placed into ADRES. Only upon the completion of the second conversion is ADERR calculated and ADTIF triggered (depending on the value of CALC).