Number of
Accumulated
Samples
AVGCTRL.
SAMPLENUM
Number of
Automatic Right
Shifts
Final Result
Precision
Automatic
Division Factor
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
41.6.2.10. Averaging
Averaging is a feature that increases the sample accuracy, at the cost of a reduced sampling rate. This
feature is suitable when operating in noisy conditions.
Averaging is done by accumulating m samples, as described in
, and dividing the result by
m. The averaged result is available in the RESULT register. The number of samples to be accumulated is
specified by writing to AVGCTRL.SAMPLENUM as shown in
The division is obtained by a combination of the automatic right shift described above, and an additional
right shift that must be specified by writing to the Adjusting Result/Division Coefficient field in AVGCTRL
(AVGCTRL.ADJRES), as described in
.
Note:
To perform the averaging of two or more samples, the Conversion Result Resolution field in the
Control C register (CTRLC.RESSEL) must be set.
Averaging AVGCTRL.SAMPLENUM samples will reduce the un-averaged sampling rate by a factor
1
AVGCTRL.SAMPLENUM
.
When the averaged result is available, the INTFLAG.RESRDY bit will be set.
Table 41-2. Averaging
Number of
Accumulated
Samples
AVGCTRL.
SAMPLENUM
Intermediate
Result
Precision
Number of
Automatic
Right
Shifts
Division
Factor
AVGCTRL.ADJRES Total
Number
of Right
Shifts
Final
Result
Precision
Automatic
Division
Factor
1
0x0
12 bits
0
1
0x0
12 bits
0
2
0x1
13
0
2
0x1
1
12 bits
0
4
0x2
14
0
4
0x2
2
12 bits
0
8
0x3
15
0
8
0x3
3
12 bits
0
16
0x4
16
0
16
0x4
4
12 bits
0
32
0x5
17
1
16
0x4
5
12 bits
2
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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