DMA triggerted by TIMx that copy data to CCR of TIMy

[megahercas6]

Posted on December 04, 2015 at 15:47

Hello, i need to implement hardware triggering by TIM8 ( as example) that will copy PWM table to TIM1->CCR1,2,3

Idea is, i want to turn 3phase motor with 3P_PWM +3N_PWM outputs (3H bride so 6lines of PWM) , and speed should be controlled by other timer period, since it will copy coeficcients to first timer CCR register I was able to make example work, but i can't only way to change frequency is to change prescaller. Or in other words, i simply need to get more resolution for my motor to spin, because if i run at 400Hz, that means i need around 7 times larger period in CCR register ( due to poles) and jumps between RPM at high speed is too big, motor start to shake. At low speed i have good RPM resolution to not feel any effect I have 256 phase steps in single sinus period. Or maybe some one can tell me, how to get more motor speed resolution at 400Hz (pwm must run 7 times faster CCR period) Here is my code:

#include ''stm32f4xx.h''
#include ''math.h''
void DMA_Config(void);
void TIM_Config(void);
uint32_t index =0;
void Delay(uint32_t a)
{
while(a)
{
a--;
asm(''nop'');
}
}
uint16_t Phase_A[256];
uint16_t Phase_B[256];
uint16_t Phase_C[256];
int main(void) 
{
Delay(0xFFFF);
uint32_t i=0;
while(i<
256
)
{
Phase_A[i]=(uint16_t)(0f*(1+sinf((6.2831853f*i/0f))));
Phase_B[i]=(uint16_t)(0f*(1+sinf(((6.2831853f*i)/0f)+2.0943f)));
Phase_C[i]=(uint16_t)(0f*(1+sinf(((6.2831853f*i)/0f)+4.1887f)));
i++;
}
TIM_Config();
DMA_Config();
DMA_ITConfig(DMA2_Stream1, DMA_IT_TC, ENABLE) ;
TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);
TIM_OC2PreloadConfig(TIM1, TIM_OCPreload_Enable);
TIM_OC3PreloadConfig(TIM1, TIM_OCPreload_Enable);
/* TIM1 counter enable */
TIM_Cmd(TIM1, ENABLE);
DMA_Cmd(DMA2_Stream1, ENABLE);
DMA_Cmd(DMA2_Stream2, ENABLE);
DMA_Cmd(DMA2_Stream6, ENABLE);
while(1);
}
void DMA_Config(void)
{
DMA_InitTypeDef DMA_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2 , ENABLE);
DMA_DeInit(DMA2_Stream6);
DMA_DeInit(DMA2_Stream2);
DMA_DeInit(DMA2_Stream1);
DMA_InitStructure.DMA_DIR
= 
DMA_DIR_MemoryToPeripheral
;
DMA_InitStructure.DMA_BufferSize
= 
256
;
DMA_InitStructure.DMA_PeripheralInc
= 
DMA_PeripheralInc_Disable
;
DMA_InitStructure.DMA_MemoryInc
= 
DMA_MemoryInc_Enable
;
DMA_InitStructure.DMA_PeripheralDataSize
= 
DMA_PeripheralDataSize_HalfWord
;
DMA_InitStructure.DMA_MemoryDataSize
= 
DMA_PeripheralDataSize_HalfWord
;
DMA_InitStructure.DMA_Mode
= 
DMA_Mode_Circular
;
DMA_InitStructure.DMA_Priority
= 
DMA_Priority_High
;
DMA_InitStructure.DMA_FIFOMode
= 
DMA_FIFOMode_Disable
;
DMA_InitStructure.DMA_FIFOThreshold
= 
DMA_FIFOThreshold_Full
;
DMA_InitStructure.DMA_MemoryBurst
= 
DMA_MemoryBurst_Single
;
DMA_InitStructure.DMA_PeripheralBurst
= 
DMA_PeripheralBurst_Single
;
DMA_InitStructure.DMA_Channel
= 
DMA_Channel_6
; 
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&TIM1->CCR3;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)Phase_C;
DMA_Init(DMA2_Stream6, &DMA_InitStructure);
DMA_InitStructure.DMA_Channel = DMA_Channel_6; 
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&TIM1->CCR2 ;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)Phase_B;
DMA_Init(DMA2_Stream2, &DMA_InitStructure);
DMA_InitStructure.DMA_Channel = DMA_Channel_6; 
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&TIM1->CCR1 ;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)Phase_A;
DMA_Init(DMA2_Stream1, &DMA_InitStructure);
TIM_DMACmd(TIM1, TIM_DMA_CC1, ENABLE);
TIM_DMACmd(TIM1, TIM_DMA_CC2, ENABLE);
TIM_DMACmd(TIM1, TIM_DMA_CC3, ENABLE);
}
void TIM_Config(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOF, ENABLE); 
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN ;
GPIO_Init(GPIOE, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7 ;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN ;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN ;
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9|GPIO_Pin_11|GPIO_Pin_13;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN ;
GPIO_Init(GPIOE, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource7, GPIO_AF_TIM1);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource0, GPIO_AF_TIM1);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource1, GPIO_AF_TIM1);
GPIO_PinAFConfig(GPIOE, GPIO_PinSource9, GPIO_AF_TIM1);
GPIO_PinAFConfig(GPIOE, GPIO_PinSource11, GPIO_AF_TIM1);
GPIO_PinAFConfig(GPIOE, GPIO_PinSource13, GPIO_AF_TIM1);
TIM_TimeBaseStructure.TIM_Prescaler = 3;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseStructure.TIM_Period = 255;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
TIM_OCInitStructure.TIM_Pulse = 0;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Set;
TIM_OC1Init(TIM1, &TIM_OCInitStructure);
TIM_OCInitStructure.TIM_Pulse = 0;
TIM_OC2Init(TIM1, &TIM_OCInitStructure);
TIM_OCInitStructure.TIM_Pulse = 0;
TIM_OC3Init(TIM1, &TIM_OCInitStructure);
TIM1->BDTR|=30;
TIM_ARRPreloadConfig(TIM1, ENABLE);
TIM_CtrlPWMOutputs(TIM1, ENABLE);
TIM_Cmd(TIM1, ENABLE);
}

[megahercas6]

Posted on December 04, 2015 at 15:58

with DMA i have even bigger problem, i can't change period, without stooping PWM generation. I need to speedup DMA CCR copying, in most streamlined fashion.

This is example how i do it, and big jumps in speed result PWM signal stopped all together

while(1)
{
if(period!=period_old)
{
if(period>period_old)
{
period_old++;
}
if(period<period_old)
{
period_old--;
}
TIM_TimeBaseStructure.TIM_Prescaler = period_old;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
Delay(0xFFF);
}
else
{
Delay(0xFFFF);
}
}