#include <Arduino.h>
#include <hardware/dma.h>


uint32_t dma_dummy, PWM_CH2_event;

// Zeitstempel erzeugen:
// DMA-Wert = Zeitpunkt, DMA-TRANS-COUNT = Ereignisse
void init_dma_pio0(void)
{
  RESETS_CLR->RESET = RESETS_RESET_dma_Msk | RESETS_RESET_busctrl_Msk;
  while (!(RESETS->RESET_DONE & RESETS_RESET_dma_Msk));
  BUSCTRL->BUS_PRIORITY = BUSCTRL_BUS_PRIORITY_DMA_W_Msk |
                          BUSCTRL_BUS_PRIORITY_DMA_R_Msk;

// PIO0_SM0  
  DMA->CH0_READ_ADDR = (uint32_t) &PWM->CH2_CTR;                // capture CH2-CTR
  DMA->CH0_WRITE_ADDR = (uint32_t) &PWM_CH2_event;              // 
  DMA->CH0_TRANS_COUNT = 1;
  DMA->CH0_CTRL_TRIG =  DREQ_PIO0_RX0 << DMA_CH1_CTRL_TRIG_TREQ_SEL_Pos |     // PIO0_RXF0
                        1 << DMA_CH0_CTRL_TRIG_CHAIN_TO_Pos |   // trigger CH1
                        2 << DMA_CH0_CTRL_TRIG_DATA_SIZE_Pos |  // word
                        DMA_CH0_CTRL_TRIG_EN_Msk;               // enable
// triggered by CH0 and triggers CH0 again  
  DMA->CH1_READ_ADDR = (uint32_t) &PIO0->RXF0;                  // transfer FIFO loeschen     
  DMA->CH1_WRITE_ADDR = (uint32_t) &dma_dummy;                  // to dummy location
  DMA->CH1_TRANS_COUNT = 1;                                     // one transfer only
  DMA->CH1_CTRL_TRIG =  0x3f<<DMA_CH0_CTRL_TRIG_TREQ_SEL_Pos |  // free running
                        0 << DMA_CH0_CTRL_TRIG_CHAIN_TO_Pos |   // Trigger CH0  
                        2 << DMA_CH0_CTRL_TRIG_DATA_SIZE_Pos |  // word
                        DMA_CH0_CTRL_TRIG_EN_Msk;               // enable
}




void setup() {
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:
int i;
  while(1) i++;
}