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]

..

[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