Digital-to-analog converter (DAC) RM0440
740/2126 RM0440 Rev 4
Note: The DAC trigger must be enabled for noise generation by setting the TENx bit in the
DAC_CR register.
22.4.10 DAC triangle-wave generation
It is possible to add a small-amplitude triangular waveform on a DC or slowly varying signal.
DAC triangle-wave generation is selected by setting WAVEx[1:0] to 10”. The amplitude is
configured through the MAMPx[3:0] bits in the DAC_CR register. An internal triangle counter
is incremented three dac_hclk clock cycles after each trigger event. The value of this
counter is then added to the DAC_DHRx register without overflow and the sum is
transferred into the DAC_DORx register. The triangle counter is incremented as long as it is
less than the maximum amplitude defined by the MAMPx[3:0] bits. Once the configured
amplitude is reached, the counter is decremented down to 0, then incremented again and so
on.
It is possible to reset triangle wave generation by resetting the WAVEx[1:0] bits.
Figure 162. DAC triangle wave generation
Figure 163. DAC conversion (SW trigger enabled) with triangle wave generation
Note: The DAC trigger must be enabled for triangle wave generation by setting the TENx bit in the
DAC_CR register.
The MAMPx[3:0] bits must be configured before enabling the DAC, otherwise they cannot
be changed.
MAMPx[3:0] max amplitude
+ DAC_DHRx base value
DAC_DHRx base value
Incrementation
ai14715c
Decrementation
0
MS45321V1
dac_pclk
0xABE
0xABE
DHR
DOR
0xABF
SWTRIG
0xAC0