Wavegenerator sonderbar

[STM8-Beginner (Gast)]

Ich habe mal den Wavegenerator, der bei STM8 Support dabei ist, 
ausprobiert.

http://www.st.com/content/ccc/resource/technical/document/application_note
/6d/93/81/1d/79/d8/44/9d/CD00280790.pdf/files/CD00280790.pdf/jcr:content 
/translations/en.CD00280790.pdf

Dann bin ich mit dem Oszi auf PIN PF0 draufgegangen (DAC output), und 
mir ist aufgefallen, dass die Verläufe nicht stimmen.
Der Output ist nämlich integriert. Z.b. wenn ein Rechteck rauskommen 
soll, sieht man am Oszi ein Dreieck.
Weiß jemand dazu eine erklärung?

CLK->CKDIVR = 0x00;
CLK->PCKENR1 |= CLK_PCKENR1_DAC | CLK_PCKENR1_TIM4;
CLK->PCKENR2 |= CLK_PCKENR2_DMA1;


DMA1_Channel3->CCR &= (uint8_t)~(DMA_CCR_CE); //Disable the selected DMA Ch.
DMA1_Channel3->CCR  = DMA_CCR_RESET_VALUE;//Reset DMA Channelx
DMA1_Channel3->CCR |= ((uint8_t)DMA_DIR_MemoryToPeripheral |
  (uint8_t)DMA_Mode_Circular |(uint8_t) DMA_MemoryIncMode_Inc);
DMA1_Channel3->CSPR &= (uint8_t)~(DMA_CSPR_PL | DMA_CSPR_16BM);
  //Clear old priority and memory data size  option
DMA1_Channel3->CSPR |= ((uint8_t)DMA_Priority_VeryHigh |
  (uint8_t)DMA_MemoryDataSize_HalfWord);
  
DMA1_Channel3->CNBTR = (uint8_t)sample_size;// Write to DMA Channelx CNBTR
//--------------------------- DMA Channel3 CPAR Configuration
DMA1_Channel3->CPARH = (uint8_t)(DAC_CH1RDHRH_ADDRESS >> (uint8_t)8);
DMA1_Channel3->CPARL = (uint8_t)(DAC_CH1RDHRH_ADDRESS);
//--------------------------- DMA Channel3 CMAR Configuration
DMA1_Channel3->CM0ARH = (uint8_t)(WavesTab[tab_index] >> (uint8_t)8);
DMA1_Channel3->CM0ARL = (uint8_t)(WavesTab[tab_index]);  
DMA1_Channel3->CCR |= DMA_CCR_CE;// DMA1 Channel 3 enable
DMA1->GCSR |= (uint8_t)DMA_GCSR_GE; // Enable the DMA


// DAC Channel1 Config: 12bit 
// Fill DAC Init param DAC_Trigger_T4_TRGO* and  DAC Channel1 Init
  // DAC CR1 Config
tmpreg1 = DAC->CH1CR1;
tmpreg1 &= (uint8_t)~(DAC_CR1_TEN | DAC_CR1_TSEL );
  // Configure for the selected DAC channel: buffer output, trigger
  // Set BOFFx bit Output Buffer disable
tmpreg1 |= (uint8_t)(DAC_CR1_BOFF );
  // Set TSELx and TEN  bits according to DAC_Trigger value
tmpreg1 |= (uint8_t)(DAC_CR1_TEN | DAC_Trigger_T4_TRGO) ;
DAC->CH1CR1 = tmpreg1;
DAC->CH1CR1 |= DAC_CR1_EN;
DAC->CH1CR2 |= DAC_CR2_DMAEN;
  
//********* TIM4 Config ********
TIM4->ARR = (uint8_t)(0x4C);// output signal frequency ca 100Hz Range 1
TIM4->PSCR = (uint8_t)(TIM4_Prescaler_16);
tmpreg1 = TIM4->CR2;
tmpreg1 &= (uint8_t)(~TIM4_CR2_MMS);
tmpreg1 |=  (uint8_t)TIM4_TRGOSource_Update;
TIM4->CR2 = tmpreg1;
TIM4->CR1 |= TIM4_CR1_CEN;

[STM8-Beginner (Gast)]

Link stimmt irgendwie nicht.

http://www.st.com/content/ccc/resource/technical/document/application_note/6d/93/81/1d/79/d8/44/9d/CD00280790.pdf/files/CD00280790.pdf/jcr:content/translations/en.CD00280790.pdf

Es handelt sich übrigens um das STM8L-Discovery Evalboard
http://www.watterott.com/de/STM8L-Discovery