51.6.2.9 Accumulation

The results of multiple, consecutive conversions can be accumulated. The number of samples to be accumulated is specified by the Sample Number field in the Average Control register (AVGCTRL.SAMPLENUM). When accumulating more than 16 samples, the result will be too large to fit the 16-bit RESULT register size. To avoid overflow, the result is right shifted automatically to fit within the available register size. The number of automatic right shifts is specified in the table below.

Note: To perform the accumulation of two or more samples, the Conversion Result Resolution field in the Control B register (CTRLB.RESSEL) must be set.
Table 51-1. Accumulation
Number of Accumulated Samples AVGCTRL. SAMPLENUM Number of Automatic Right Shifts Final Result Precision Automatic Division Factor
1 0x0 0 12 bits 0
2 0x1 0 13 bits 0
4 0x2 0 14 bits 0
8 0x3 0 15 bits 0
16 0x4 0 16 bits 0
32 0x5 1 16 bits 2
64 0x6 2 16 bits 4
128 0x7 3 16 bits 8
256 0x8 4 16 bits 16
512 0x9 5 16 bits 32
1024 0xA 6 16 bits 64
Reserved 0xB –0xF 12 bits 0