Doc ID16895 Rev 2

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AN3126

DAC main features

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When using the DMA, the overall performance of the system is increased by freeing up the

core. This is because data is moved from memory to DAC by DMA, without needing any

actions by the CPU. This keeps CPU resources free for other operations.

Figure 4. DAC interaction with DMA

1.6

DMA underrun error

When the DMA is used to provide DAC with the pattern waveform, there are some cases

where the DMA transfer is faster than the DAC conversion, In this case, DAC detects that a

part of the pattern waveform has been ignored and was not converted. It then sets the "DMA

underrun Error" flag.

The underrun error can be handled using a shared IRQ channel with the triggering Timer or

by a dedicated interrupt when DAC is not triggered by TIM6.

1.7

White noise generator

1.7.1

Definition

The STM32 microcontrollers DAC provides user with a pseudo random code generator,

sketched in Figure 5. Depending on what taps are used on the shift register, a sequence of

ai18303

DAC

DMA

RAM

(Pattern Table 1)

(Pattern Table 2)

Channel 1

Output

Channel 2

Output

DAC Triggers

CPU