Doc ID16895 Rev 2

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AN3126

Application examples

23

In this application, coprocessing is mandatory to permit a simultaneous Wave read (from the

external memory source) and write (in the DAC register).

Figure 17. CPU and DMA activities during wave playing process

ai18316

Transfer 512 bytes data from wavBuffur_1 to DAC

(Transfer triggered by TIM6_TRGO)

Idle

(No activity)

CPU

DMA

TIM6_TRGO

. . . . . . . . . . . . . . . . . . . . . . . . . .

512 pulses

Transfer 512 byte data

from MicroSD memory in

wavBuffer_2

Decrement the WaveDataLength

counter and DMA reconfiguration

Transfer 512 bytes data from wavBuffur_2 to DAC

(Transfer triggered by TIM6_TRGO)

Transfer 512 byte data

from MicroSD memory in

wavBuffer_1

Idle

(No activity)

. . . . . . . . . . . . . . . . . . . . . . . . . .

512 pulses

. . . . . .

Decrement the WaveDataLength

counter and DMA reconfiguration