GD32F20x User Manual
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register. The amplitude of the noise can be configured by the DAC noise wave bit width
(DWBWx) bits in the DAC_CTL register.
There is a Linear Feedback Shift Register (LFSR) in the DAC control logic. In the LFSR noise
mode, the LFSR noise signal is added to the DACx_DH value. When the configured DAC
noise wave bit width is less than 12, the noise signal equals to the LSB DWBWx bits of the
LFSR register.
Figure 15-2. DAC LFSR algorithm
9
7
8
6
5
4
3
2
1
11
10
0
X
6
X
0
X
4
X
XOR
X
12
NOR
12
In the triangle noise mode, a triangle signal is added to the DACx_DH value. The minimum
value of the triangle signal is 0, while the maximum value of the triangle signal is
(2<<DWBWx)-1.
Figure 15-3. DAC triangle noise wave
(2<<DWBWx)-1 +
DACx_DH value
DACx_DH value
15.3.7.
DAC output voltage
The analog output voltages on the DAC pin are determined by the following equation:
DAC
output
=V
REF+
*DAC_DO/4095 (15-1)
The digital input is linearly converted to an analog output voltage, its range is 0 to V
REF+
.
Summary of Contents for GD32F20 Series
Page 191: ...GD32F20x User Manual 191 Bits Fields Descriptions 31 0 TRNDATA 31 0 32 Bit Random data ...
Page 290: ...GD32F20x User Manual 290 conversion is ongoing ...
Page 325: ...GD32F20x User Manual 325 15 0 ALRM 15 0 RTC alarm value low ...
Page 385: ...GD32F20x User Manual 385 ...
Page 523: ...GD32F20x User Manual 523 clears AERR bit by writing 0 to it ...