GD32W51x User Manual
1009
channel in the inserted group will be converted, and the next trigger will select another
channel. And writing to the ICGSEL[1:0] bit field will use the lowest channel as the selected
conversion channel.
Conversion request priority
The conversion of the inserted group has a higher priority than the regular group. The regular
conversion that is already in progress will be immediately interrupted by the inserted
conversion request. When the inserted conversion sequence ends, if RCCM remains at 1,
the continuous regular conversion will start again.The value of the RCHPDT bit indicates that
the interrupted regular conversion is delayed.
If an inserted conversion is pending or already in progress, you cannot start other inserted
conversions: as long as ICPF=1, any request to launch an inserted conversion (software or
trigger start) will be ignored. The regular conversion is the same.
When the inserted conversion is in progress (ICPF=1), write 1 to the SRCS bit of
HPDF_FLTyCTL0 to request regular conversion. When the inserted sequence is completed,
the priority indicates the next step to perform regular conversion, and the delayed start is
indicated by the RCHPDT bit.
30.3.8.
Digital filter
The digital filter of the HPDF module is of Sinc
X
type. The input data stream is filtered by Sinc
X
,
thereby reducing the output data rate and increasing the output data resolution. Configure the
order and oversampling rate (decimation filtering) of the Sinc
X
filter by the SFO[2:0] and
SFOR[9:0] bits in the HPDF_FLTySFCFG register. The user can configure the order and
oversampling rate of the Sinc
X
filter according to the desired resolution. The relationship
between the maximum output resolution of Sinc
X
filtering and oversampling filtering is as
follows:
Table 30-5. The relationship between the maximum output resolution and
oversampling filtering of Sinc
X
filtering
SFOR
Sinc
Sinc
2
FastSinc
Sinc
3
Sinc
4
Sinc
5
x
±
x
±
x
2
±
2x
2
±
x
3
±
x
4
±
x
5
4
±
4
±
16
±
32
±
64
±
256
±
1024
8
±
8
±
64
±
64
±
512
±
4096
±
32768
32
±
32
±
1024
±
2048
±
32768
±
1048576
±
33554432
64
±
64
±
4096
±
8192
±
262144
±
16777216
±
1073741824
128
±
128
±
16384
±
32768
±
2097152
±
268435456
-
256
±
256
±
65536
±
131072
±
16777216
Under full-scale input
conditions, the result w ill
overflow
1024
±
1024
±
1048576
±
2097152
±
1073741824
Note:
The maximum output resolution in this table comes from the peak data value of the
filter output.