GD32A50x User Manual
278
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
128x 0x7FF80 0xFF80 0xFFC0 0xFFE0 0xFFF0 0x7FF8 0x3FFC 0x1FFE 0x0FFF 0x07FF
256x 0xFFF00 0xFF00 0xFF80 0xFFC0 0xFFE0 0xFFF0 0x7FF8 0x3FFC 0x1FFE 0x0FFF
When compared to standard conversion mode, the conversion timings of oversampling mode
do not change, and the sampling time is maintained the same as that of standard conversion
mode during the whole oversampling sequence. New data are provided every N conversion,
with an equivalent delay equal to:
N*t
ADC
=N*(t
SMPL
+t
CONV
) (14-2)
14.5.
ADC sync mode
In devices with more than one ADC, the ADC sync mode can be used. In ADC sync mode,
the conversion starts alternately or simultaneously triggered by ADC0 to ADC1,
according to
the sync mode configurated by the SYNCM[3:0] bits in ADC1_CTL0 register.
In sync mode, when configure the conversion which is triggered by an external event, the
ADC1 must be configured as triggered by the software. However, the external trigger must
be enabled for ADC0 and ADC1.
The following modes can be configured in
Table 14-6. ADC sync mode table
Table 14-6. ADC sync mode table
SYNCM[3: 0]
mode
0000
Free mode
0110
Routine parallel mode
0111
Routine follow-up fast mode
1000
Routine follow-up slow mode
In ADC sync mode, the DMA bit must be set even if it is not used; the converted data of ADC1
routine channel can be read from the ADC0 data register.