Please Help - Timer not generating output on pin

[Joe.H]

I'm attempting to output a 50% duty cycle clock signal on Port C bit 7.

I running on a STM32F407

I have verified that that output is working when set the pin as function 0 and toggled.

Using function 2 when associated with the timer 3 channel 2

I have also verified with a debugger that the timer is running.

I am using the following code - can someone point out my error.

I tried the output mode at PWM and as Toggle - neither work.

I've read the 407 manual and AN4776 (App Note on timers) multiple times but no help there.

Thanks in advance for your help

<code>

void SCCB_Init(void)

{

Config_STM_Pin(GPIOC, 7, 2, H_GPIO_Output, H_GPIO_Output_PushPull, SlewRate_Medium, No_Pull_Up_or_Down);

RCC->APB1ENR |= RCC_APB1ENR_TIM3EN; // turn clock on uses clock at 42 mhz

Wait_Block_MicroSec(500);

TIM3->ARR = 4200;

TIM3->SR = 0; // reset done flag

TIM3->CCMR1 = TIM_CCMR1_OC2M_0 | TIM_CCMR1_OC2M_1;

TIM3->CCER = TIM_CCER_CC1E;

TIM3->CCR2 = TIM3->ARR / 2;

TIM3->CR1 = TIM_CR1_CEN;

}

</code>

[Tesla DeLorean]

Make sure GPIOC clock is enabled, make sure the AF setting correct for TIM3_CH2

Check registers in debugger, make sure TIM is ticking

[waclawek.jan]

Posted code looks good.

Read out and check/post the relevant GPIO and timer registers' content.

JW