Configure the timers count at 32-bit

[u23]

Posted on July 18, 2014 at 08:39

Hi,

I'm using the device STM32F030C8T6 that has all the timers count at 16-bit. I need using the timer count at 32-bit. In the data sheet in the page 67 reads ''Maximum possible count with 32-bit counter''. How can I configure the timer to count up to 32-bit? Thanks

[Tesla DeLorean]

Posted on July 18, 2014 at 15:19

Some STM32F0 parts have a 32-bit counter, the part you have chosen does not.

You'd need to cascade at pair of 16-bit counters in master/slave mode This might be illustrative STM32F10x_StdPeriph_Lib_V3.5.0\Project\STM32F10x_StdPeriph_Examples\TIM\Cascade_Synchro

[u23]

Posted on July 18, 2014 at 16:22

Ok, Thanks

[u23]

Posted on July 21, 2014 at 09:44

I have configurated the TIM2 and TIM3 in cascade mode:

uint8_t TIMER_ConfigSynchInCascade( void ) {   TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;     TIM_OCInitTypeDef  TIM_OCInitStructure;       /* TIM2 and TIM3 clock enable */     // --------------------------------------------------------------------------     RCC_APB2PeriphClockCmd(RCC_APB1Periph_TIM2 | RCC_APB1Periph_TIM3, ENABLE);          /* Time base configuration */     // --------------------------------------------------------------------------   TIM_TimeBaseStructure.TIM_Period = 65535;   TIM_TimeBaseStructure.TIM_Prescaler = 15;   TIM_TimeBaseStructure.TIM_ClockDivision = 0;   TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;   TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);   TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);   /* Select the Master Slave Mode */   TIM_SelectMasterSlaveMode(TIM2, TIM_MasterSlaveMode_Enable);   /* Master Mode selection */   TIM_SelectOutputTrigger(TIM2, TIM_TRGOSource_Update);   /* Slave Mode selection: TIM3 */   TIM_SelectSlaveMode(TIM3, TIM_SlaveMode_Gated);   TIM_SelectInputTrigger(TIM3, TIM_TS_ITR1);   /* TIM enable counter */   TIM_Cmd(TIM3, ENABLE);   TIM_Cmd(TIM2, ENABLE);     return 0; } I

n the main function

, the LED4

is

turned on and off

in the following mode:

static __IO uint8_t Debug = 0; #define LEDToggleValue ((uint32_t) 100000) static __IO uint32_t CounterTimers = 0; int main(void) {    /* Initialize Leds mounted on STM3210X-EVAL board */   STM_EVAL_LEDInit(LED4);   // Configura i timers in cascata   TIMER_ConfigSynchInCascade();   while (1)   {             // Toggle led             CounterTimers = TIMER_GetCounter(TIM2)+TIMER_GetCounter(TIM3);             if (  CounterTimers > LEDToggleValue )                 STM_EVAL_LEDOn(LED4);             else                     STM_EVAL_LEDOff(LED4);     } } The LED4 is ever off!

I have

done something wrong

in the configuration

? Thanks

[maxime]

Posted on July 21, 2014 at 16:11

Hi, 

Not sure but I think you should use :RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2 | RCC_APB1Periph_TIM3, ENABLE); instead of RCC_APB2PeriphClockCmd(RCC_APB1Periph_TIM2 | RCC_APB1Periph_TIM3, ENABLE);

[Tesla DeLorean]

Posted on July 21, 2014 at 17:34

CounterTimers = TIMER_GetCounter(TIM2)+TIMER_GetCounter(TIM3);

Does these functions deal with shifting the 16-bit word suitably?

[u23]

Posted on July 22, 2014 at 08:45

I have corrected the errors, but the timer TIM3 not counter!

The TIMER_GetCounter(TIM2) function return the value in the range [0÷65535], but the TIMER_GetCounter(TIM3) function return zero.

[u23]

Posted on July 24, 2014 at 08:38

The solution is descript below:

uint8_t TIMER_ConfigSynchInCascade( void ) {     TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;     uint16_t PrescalerValue_RPM = 0;   RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM16 | RCC_APB2Periph_TIM17, ENABLE);    /* Timer frequency configuration at 12 MHz */     PrescalerValue_RPM = (uint16_t) (SystemCoreClock  / 12000000) - 1;        /* Time base configuration */   TIM_TimeBaseStructure.TIM_Period = 65535;   TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue_RPM;   TIM_TimeBaseStructure.TIM_ClockDivision = 0;   TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;   TIM_TimeBaseInit(TIM16, &TIM_TimeBaseStructure);   TIM_TimeBaseInit(TIM17, &TIM_TimeBaseStructure);   /* Select the Master Slave Mode */   TIM_SelectMasterSlaveMode(TIM16, TIM_MasterSlaveMode_Enable);   /* Master Mode selection */   TIM_SelectOutputTrigger(TIM16, TIM_TRGOSource_Update);   /* Slave Mode selection: TIM17 */   TIM_SelectSlaveMode(TIM17, TIM_SlaveMode_Gated);   TIM_SelectInputTrigger(TIM17, TIM_TS_ITR1);   /* Select the Master Slave Mode */   TIM_SelectMasterSlaveMode(TIM17, TIM_MasterSlaveMode_Enable);   /* Master Mode selection: TIM17 */   TIM_SelectOutputTrigger(TIM17, TIM_TRGOSource_Update);     /* TIM enable counter */   TIM_Cmd(TIM17, ENABLE);   TIM_Cmd(TIM16, ENABLE);          return 0; } The function that return the counter value at 32-bit is: uint32_t GetCounter32Bit ( void ) {     uint16_t a, b, c, d;     /* Reading twice to avoid overflow in the middle of reading */     a = TIM16->CNT;     b = TIM17->CNT;     c = TIM16->CNT;     d = TIM17->CNT;     if((a != c) || (b != d))         return ((uint32_t)c << 16) | d;     else         return ((uint32_t)a << 16) | b; }    

I

hope this is

clear

!