DMA CCR1 CCR2 conflict I can have signal on PB6 or PB7 but not both on one time. by changing CCR1 and CCR2 arrangement. CCR1, CCR1 =signal on PB6 CCR1, CCR2 = signal on PB7 CCR2, CCR2 = signal on PB7 CCR2, CCR1 = signal on PB6

[tkor.1]

#define SAMPLES 100
#include <libmaple/dma.h>
 
dma_tube_config dma_cfg, dma_cfg2;
int val1[SAMPLES];
int val2[SAMPLES];                   // *******************
int amp = 35;
int cnt = 0;
int time_track = 0;
float stp = 6.2831 / SAMPLES;
int ret = 17;
int out1 = PB7; // TIM4_CH2 DMA_CH4 . 
int out2 = PB6; // TIM4_CH1 DMA_CH3 .                     *************************** 
 
timer_dev *dev1 = PIN_MAP[out2].timer_device;   
timer_dev *dev2 = PIN_MAP[out2].timer_device;
 
void timer_conf()
{
// PB7 TIM4_CH2 DMA_CH4
  timer_dma_set_base_addr(dev1, TIMER_DMA_BASE_CCR2);          // CCR1, CCR1 =  PB6
  timer_dma_set_burst_len(dev1, 1);                            // CCR1, CCR2 =  PB7
  timer_dma_enable_req(dev1, PIN_MAP[out1].timer_channel);     //CCR2, CCR2 = PB7
  timer_set_reload(dev1, 102);                                 //CCR2, CCR1 =  PB6
  timer_set_prescaler(dev1, 0);
 
 
  // PB6 TIM4_CH1 DMA_CH3 .                                  *********************
  timer_dma_set_base_addr(dev2, TIMER_DMA_BASE_CCR2);
  timer_dma_set_burst_len(dev2, 1);
  timer_dma_enable_req(dev2, PIN_MAP[out2].timer_channel);
  timer_set_reload(dev2, 102);
  timer_set_prescaler(dev2, 0);
}
void dma_conf()
{
  dma_init(DMA1);
 // PB7 TIM4_CH2 DMA_CH4
  // PB6 TIM4_CH1 DMA_CH3
  dma_cfg.tube_dst = &(dev1->regs.gen->DMAR);                // PB7
  dma_cfg.tube_dst = &(dev2->regs.gen->DMAR);                // PB6********************
  dma_cfg.tube_src = val1;                                   // PB7
  dma_cfg.tube_src = val2;                                   // PB6********************
  dma_cfg.tube_src_size = DMA_SIZE_32BITS;
  dma_cfg.tube_nr_xfers = SAMPLES;
  dma_cfg.tube_flags = DMA_CFG_SRC_INC | DMA_CFG_CIRC;
  
  dma_cfg.tube_req_src = DMA_REQ_SRC_TIM4_CH2;               //PB7
  dma_cfg.tube_req_src = DMA_REQ_SRC_TIM4_CH1;               //PB6 ********************
  dma_cfg.target_data = 0;
  ret = dma_tube_cfg(DMA1, DMA_CH4, &dma_cfg);
  ret = dma_tube_cfg(DMA1, DMA_CH3, &dma_cfg);
}
void dma_start()
{
  // PB7 TIM4_CH2 DMA_CH4
  dma_enable(DMA1, DMA_CH4);
 timer_resume(dev1);
  dma_enable(DMA1, DMA_CH3);
  timer_resume(dev2);
 
}
void init_wave()
{
  int i;
  for (i = 0; i < SAMPLES; i++)
  {
    val1[i] = 50 + amp * sin(stp * i);
    val2[i] = 50 + amp * sin(stp * i);                      //************************
  }
}
void setup() {
  pinMode(out1, PWM);
  pinMode(out2, PWM);
 
 
  timer_conf();
  dma_conf();
  dma_start();
  init_wave();
}
void loop() {
}

[waclawek.jan]

What is this, Arduino and 'F103?

I am not familiar with Arduino, but it appears that you want to run two different DMA channels using the same timer's DCR/DMAR registers. This won't work. But why don't you do it in the way it's designed, i.e. using only one DMA channel updating both CCR1 and CCR2 upon a single trigger from Update?

You may want to read out the timer and DMA registers content and check them against the respective chapters in RM, or post them here.

JW

[tkor.1]

I am using arduino IDE and stm32f103, I need 2 outputs from timer # 4, I have one on PB7 to get second I have a problem.

 But why don't you do it in the way it's designed, i.e. using only one DMA channel updating both CCR1 and CCR2 upon a single trigger from Update ? =. This i don't know