Posted on August 21, 2012 at 22:59
The blue waveform is TIM1, yellow is TIM3. Notice that TIM3 is now acting withTIM_OCPolarity_High and in PWM1 mode. _
TIM3_CH1 goes high immediately after callingTIM_OC1Init(TIM3, &TIM_OCInitStructure); It is the combination of polarity and PWM mode that defines if the output will be HIGH or LOW. Timer have not even started counting, and the output goes high.
I believe this is a very bad bug here.Any comments/advices?
I'm hammering my table with my head the whole evening. I can't get the simpliest thing to work. Ok, here's the problem: I need TIM1 to gate TIM3. I've got TIM1 configured as a single-shot master with either TIM_TRGOSource_Enable orTIM_TRGOSource_OC1Ref signal sent to slaves. Then I have TIM3 set as a slave PWM generator. I want TIM3 to immidiately start firing pulses. Pictures will tell the better story:
The blue waveform is TIM1, yellow is TIM3. Notice that TIM3 is now acting withTIM_OCPolarity_High and in PWM1 mode. _
Absolutely the same picture
_ is whenTIM_OCPolarity_Low and PWM2 mode. And this is crazy, because notice that yellow is HIGH _before_ the gate comes to the scene. The same picture with different scale:
TIM3_CH1 goes high immediately after callingTIM_OC1Init(TIM3, &TIM_OCInitStructure); It is the combination of polarity and PWM mode that defines if the output will be HIGH or LOW. Timer have not even started counting, and the output goes high.
I believe this is a very bad bug here.Any comments/advices?
#include ''stm32f10x_tim.h''
#include ''stm32f10x_rcc.h''
#include ''stm32f10x_gpio.h''
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
TIM_BDTRInitTypeDef TIM_BDTRInitStructure;
void
RCC_Configuration(
void
);
void
GPIO_Configuration(
void
);
void
tim3ch3onePulse()
{
/*!< At this stage the microcontroller clock setting is already configured,
this is done through SystemInit() function which is called from startup
file (startup_stm32f10x_xx.s) before to branch to application main.
To reconfigure the default setting of SystemInit() function, refer to
system_stm32f10x.c file
*/
/* System Clocks Configuration */
RCC_Configuration();
/* GPIO Configuration */
GPIO_Configuration();
/* TIM3 Peripheral Configuration ----------------------------------------*/
/* TIM3 works in Gated mode. */
TIM_SelectSlaveMode(TIM3, TIM_SlaveMode_Gated);
TIM_SelectInputTrigger(TIM3, TIM_TS_ITR0);
/* TIM3 Slave Configuration: PWM1 Mode */
TIM_TimeBaseStructure.TIM_Prescaler = 23;
TIM_TimeBaseStructure.TIM_Period = 50;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_Pulse = 5;
TIM_OC1Init(TIM3, &TIM_OCInitStructure);
/* TIM1 Peripheral Configuration ----------------------------------------*/
/* Time Base configuration */
TIM_TimeBaseStructure.TIM_Prescaler = 23;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseStructure.TIM_Period = 401;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
/* Channel 1 Configuration in PWM mode */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;
TIM_OCInitStructure.TIM_Pulse = 300;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_Low;
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;
TIM_OC1Init(TIM1, &TIM_OCInitStructure);
/* Master Mode selection */
TIM_SelectOutputTrigger(TIM1, TIM_TRGOSource_Enable);
/* Select the Master Slave Mode */
TIM_SelectMasterSlaveMode(TIM1, TIM_MasterSlaveMode_Enable);
TIM_CtrlPWMOutputs(TIM1, ENABLE);
TIM_SelectOnePulseMode(TIM1, TIM_OPMode_Single);
/* TIM enable counter */
/* Main Output Enable */
/* TIM1 counter enable */
TIM_Cmd(TIM1, ENABLE);
TIM_Cmd(TIM3, ENABLE);
while
(1)
{}
}
void
GPIO_Configuration(
void
)
{
GPIO_InitTypeDef GPIO_InitStructure;
/* GPIOA Configuration: TIM1 Channel1 and TIM3 Channel1 as alternate function push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_8;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_ResetBits(GPIOA, GPIO_Pin_6);
}
void
RCC_Configuration(
void
)
{
/* TIM1, GPIOA and GPIOB clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 | RCC_APB2Periph_GPIOA |
RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE);
/* TIM3 and TIM4 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
}