
Analog-to-digital converter (ADC)
RM0453
562/1454
RM0453 Rev 2
Figure 82. Numerical example with 5-bits shift and rounding
The
below gives the data format for the various N and M combination, for a raw
conversion data equal to 0xFFF.
The conversion timings in oversampled mode do not change compared to standard
conversion mode: the sample time is maintained equal during the whole oversampling
sequence. New data are provided every N conversion, with an equivalent delay equal to N x
t
CONV
= N x (t
SMPL
+ t
SAR
). The flags features are raised as following:
•
the end of the sampling phase (EOSMP) is set after each sampling phase
•
the end of conversion (EOC) occurs once every N conversions, when the oversampled
result is available
•
the end of sequence (EOCSEQ) occurs once the sequence of oversampled data is
completed (i.e. after N x sequence length conversions total)
0
3
7
11
15
19
Raw 20-bit data:
B
F
15
B
7
3
7
D
1
D
MS31929V1
Final result after 5-bits shift
and rounding to nearest
Table 108. Maximum output results vs N and M. Grayed values indicates truncation
Oversa
mpling
ratio
Max
Raw data
No-shift
OVSS =
0000
1-bit
shift
OVSS =
0001
2-bit
shift
OVSS =
0010
3-bit
shift
OVSS =
0011
4-bit
shift
OVSS =
0100
5-bit
shift
OVSS =
0101
6-bit
shift
OVSS =
0110
7-bit
shift
OVSS =
0111
8-bit
shift
OVSS =
1000
2x
0x1FFE
0x1FFE
0x0FFF
0x0800
0x0400
0x0200
0x0100
0x0080
0x0040
0x0020
4x
0x3FFC
0x3FFC
0x1FFE
0x0FFF
0x0800
0x0400
0x0200
0x0100
0x0080
0x0040
8x
0x7FF8
0x7FF8
0x3FFC
0x1FFE
0x0FFF
0x0800
0x0400
0x0200
0x0100
0x0080
16x
0xFFF0
0xFFF0
0x7FF8
0x3FFC
0x1FFE
0x0FFF
0x0800
0x0400
0x0200
0x0100
32x
0x1FFE0
0xFFE0
0xFFF0
0x7FF8
0x3FFC
0x1FFE
0x0FFF
0x0800
0x0400
0x0200
64x
0x3FFC0 0xFFC0
0xFFE0
0xFFF0
0x7FF8
0x3FFC
0x1FFE
0x0FFF
0x0800
0x0400
128x
0x7FF80
0xFF80
0xFFC0
0xFFE0
0xFFF0
0x7FF8
0x3FFC
0x1FFE
0x0FFF
0x0800
256x
0xFFF00
0xFF00
0xFF80
0xFFC0
0xFFE0
0xFFF0
0x7FF8
0x3FFC
0x1FFE
0x0FFF