How to use the timer 6 or timer 7 in stm32f100RB? - c

Question

I'm learning to use the MCU STM32f100RB, which is based on the arm cortex m3.
To test the timer 6, I wrote a bit of codes as following.It's supposed to make the led blink. But it does not work.Anyone can give me a hand telling me what's problem? Is the timer initialized correctly?
Thx
#include "stm32f10x.h"
#include "stm32f10x_rcc.h"
#include "stm32f10x_gpio.h"
#include "stm32f10x_tim.h"
void delay_millisec(register unsigned short n);
int main(void)
{
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC | RCC_APB1Periph_TIM6, ENABLE);
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_StructInit(&GPIO_InitStructure);
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8; //enable the pin 8 and pin 9
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_Init(GPIOC, &GPIO_InitStructure);
while(1)
{
GPIO_WriteBit(GPIOC, GPIO_Pin_8, Bit_RESET);
delay_millisec(1000);
GPIO_WriteBit(GPIOC, GPIO_Pin_8, Bit_SET);
delay_millisec(1000);
}
return 0;
}
void delay_millisec(register unsigned short n)
{
if (n > 1) n--;
TIM6->PSC = 23999; // Set prescaler to 24,000 (PSC + 1)
TIM6->ARR = n; // n = 1 gives 2msec delay rest are ok
TIM6->CNT = 0;
TIM6->EGR = TIM_EGR_UG; // copy values into actual registers!
// Enable timer in one pulse mode
TIM6->CR1 |= (TIM_CR1_OPM | TIM_CR1_CEN);
while (TIM6->CR1 & TIM_CR1_CEN); // wait for it to switch off
}

Answer 1

You are not enabling the timer peripheral's clock, from what I can see.
Note that your code does this:
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC | RCC_APB1Periph_TIM6, ENABLE);
^ ^ ^
| | |
APB2 APB2 APB1?!!
but this can't be right; you're using constants for peripheral clock 1 and 2 in the same call, to clock 2. That won't fly.
You need to have:
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM6, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);
You really should be using the Standard Peripheral Library for the timer initialization too, no point in poking registers directly.