stm32f407 TIM1 and TIM8 sync

[zarkscon]

Posted on March 14, 2015 at 15:18

Hello I'm trying to synchronize TIM1 and TIM8 (slaves) via TIM2 (master).. I checked the manual and says it can be done (p. 554/1710).. Although TIM2 works fine, TIM1 and TIM8 are off..

Please check my code bellow and help me out!

/* Includes ------------------------------------------------------------------*/
#include ''stm32f4xx.h''
#include ''stm32f4xx_rcc.h''
#include ''stm32f4xx_gpio.h''
#include ''stm32f4xx_tim.h''
#include ''misc.h''
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
TIM_BDTRInitTypeDef TIM_BDTRInitStructure;
/* Private function prototypes -----------------------------------------------*/
void
TIM_Config(
void
);
/* Private functions ---------------------------------------------------------*/
int
main(
void
)
{
TIM_Config();
/* TIM1 Peripheral Configuration ----------------------------------------*/
/* TIM1 Slave Configuration: PWM1 Mode */
TIM_TimeBaseStructure.TIM_Period = 2;
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 1;
TIM_OC1Init(TIM1, &TIM_OCInitStructure);
/* Slave Mode selection: TIM1 */
TIM_SelectSlaveMode(TIM1, TIM_SlaveMode_Gated);
TIM_SelectInputTrigger(TIM1, TIM_TS_ITR1);
/* TIM8 Peripheral Configuration ----------------------------------------*/
/* TIM8 Slave Configuration: PWM1 Mode */
TIM_TimeBaseStructure.TIM_Period = 2;
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM8, &TIM_TimeBaseStructure);
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 1;
TIM_OC1Init(TIM8, &TIM_OCInitStructure);
/* Slave Mode selection: TIM8 */
TIM_SelectSlaveMode(TIM8, TIM_SlaveMode_Gated);
TIM_SelectInputTrigger(TIM8, TIM_TS_ITR1);
/* TIM2 Peripheral Configuration ----------------------------------------*/
/* Time Base configuration */
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseStructure.TIM_Period = 255;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_RepetitionCounter = 4;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
/* Channel 1 Configuration in PWM mode */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
TIM_OCInitStructure.TIM_Pulse = 127;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_Low;
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;
TIM_OC1Init(TIM2, &TIM_OCInitStructure);
/* Master Mode selection */
TIM_SelectOutputTrigger(TIM2, TIM_TRGOSource_Update);
/* Select the Master Slave Mode */
TIM_SelectMasterSlaveMode(TIM2, TIM_MasterSlaveMode_Enable);
/* TIM2 counter enable */
TIM_Cmd(TIM2, ENABLE);
/* TIM enable counter */
TIM_Cmd(TIM1, ENABLE);
TIM_Cmd(TIM8, ENABLE);
/* Main Output Enable */
TIM_CtrlPWMOutputs(TIM2, ENABLE);
while
(1)
{}
}
void
TIM_Config(
void
)
{
GPIO_InitTypeDef GPIO_InitStructure;
/* GPIOA and GPIOC clocks enable */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA | RCC_AHB1Periph_GPIOC, ENABLE);
/* TIM1 and TIM8 clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 | RCC_APB2Periph_TIM8, ENABLE);
/* TIM2 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
/* GPIOA Configuration: TIM1 and TIM2 Channel1 as alternate function push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_0;
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_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);
/* GPIOC Configuration: TIM8 Channel1 as alternate function push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
GPIO_Init(GPIOC, &GPIO_InitStructure);
/* Connect TIM pins to AF1 */
GPIO_PinAFConfig(GPIOA, GPIO_PinSource8, GPIO_AF_TIM1);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource0, GPIO_AF_TIM2);
/* Connect TIM pins to AF3 */
GPIO_PinAFConfig(GPIOC, GPIO_PinSource6, GPIO_AF_TIM8);
}

Thanks in advance #discovery #stm32 #stm32f4

[Tesla DeLorean]

Posted on March 14, 2015 at 16:56

TIM_CtrlPWMOutputs(TIM2, ENABLE);

Don't need that for TIM2, critical for TIM1 and TIM8 (they're special)They also need the repetition count, set to zero.

[zarkscon]

Posted on March 14, 2015 at 17:10

Thanks for the help but still nothing happens though TIM2 works fine..

[Tesla DeLorean]

Posted on March 14, 2015 at 18:25

Ok, I don't have my scope with me.

What board are you doing this on? And what signals do you expect to see (nature, frequency, etc)?

[zarkscon]

Posted on March 14, 2015 at 23:52

I'm using stm32f407vgt6 discovery board and I want to start TIM1 and TIM8 simultaneously.. I used this as my template (

https://github.com/devthrash/STM32F4-workarea/tree/master/Project/STM32F4xx_StdPeriph_Examples/TIM/TIM_Synchro

)  which works fine but not when I change it for TIM1 and TIM8..

[Tesla DeLorean]

Posted on March 15, 2015 at 02:34

So you expect the timers to output a continuous frequency, what frequency, or modulate?

[zarkscon]

Posted on March 15, 2015 at 12:08

I want TIM1 and TIM8 to work at 42.5KHz, which I haven't fix it inside the code, but I don't think it's an issue. TIM2 works at 105.3KHz right now, checked with my oscilloscope.. My HSE frequency is at 25MHz, usually I change it to 80MHz (system_stm32f4xx.c)..

[Tesla DeLorean]

Posted on March 16, 2015 at 01:59

Really not seeing Gated mode being at all appropriate for that. Surely a Reset mode driven by a one-shot would be the way to phase align two timers.

[Tesla DeLorean]

Posted on March 16, 2015 at 02:02

42.5 KHz is not cleanly divisible into 80 MHz, perhaps you'd want to try 85 MHz?

[zarkscon]

Posted on March 16, 2015 at 18:13

I can't see how reset mode would help me out, since it just resets the two clocks (I'll check it out though)..

The frequency of HSE doesn't mean a lot.. It's the timer period and prescaller which define the appropriate frequency.. For example on my code (not this one i posted here) I have SYSCLK=168MHz and HSE=80MHz.. Then I wrote that

#define FREQUENCY 42500 /* output frequency 42500 KHz */
/* Compute the value to be set in ARR register to generate the desired signal frequency */
TimerPeriod = ((SystemCoreClock/2) / FREQUENCY) - 1;
TIM_TimeBaseStructure.TIM_Period = TimerPeriod - 1;
TIM_TimeBaseStructure.TIM_Prescaler = 0;

and the oscilloscope shows 5KHz..