/* DAC load pulse generator */
TIM1_ARR = 6 - 1; /* 20 MHz sample rate */
TIM1_CCR1 = 3; /* 50% duty cycle on PWM output CH1 */
TIM1_CCMR1 = 0x0068; /* PWM mode 1 on CH1 */
TIM1_EGR = 1; /* generate update event */
TIM1_CCER = 4; /* enable CH1N output */
TIM1_BDTR = 0x8000; /* main output enable */
TIM1_SMCR = 0x25; /* gated by TIM3 */
TIM1_CR1 = 0x0001; /* start timer */

void TIM1_init (void)
{
u16 TIMCounter = 1200;// 2048
u16 TIMAutoreload = 34;// 34
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);

TIM_TimeBaseStructure.TIM_Period = 1;// TIM1_ARR = 2
TIM_TimeBaseStructure.TIM_Prescaler = 1;//
TIM_TimeBaseStructure.TIM_ClockDivision = 0;//
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);

TIM_OCInitTypeDef TIM_OCInitStructure;

TIM_GenerateEvent(TIM1, TIM_EventSource_Update);//TIM1_EGR = 1
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;//TIM1_CCMR1
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;// TIM1_CCER = 4
TIM_OCInitStructure.TIM_Pulse = 30;// TIM1_CCR1 = 30
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_Low;
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Set;

TIM_OC1Init(TIM1, &TIM_OCInitStructure);

TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);

TIM_BDTRInitTypeDef TIM_BDTRInitStructure;

TIM_BDTRInitStructure.TIM_OSSRState = TIM_OSSRState_Disable;
TIM_BDTRInitStructure.TIM_OSSIState = TIM_OSSIState_Disable;
TIM_BDTRInitStructure.TIM_LOCKLevel = 0;
TIM_BDTRInitStructure.TIM_DeadTime = 0;// =value/(1/72mhz)
TIM_BDTRInitStructure.TIM_Break = TIM_Break_Disable;
TIM_BDTRInitStructure.TIM_BreakPolarity = TIM_BreakPolarity_High;
TIM_BDTRInitStructure.TIM_AutomaticOutput = TIM_AutomaticOutput_Enable;

TIM_BDTRConfig(TIM1, &TIM_BDTRInitStructure);

TIM_SetCounter(TIM1, TIMCounter);// Sets the TIM Counter Register value
TIM_SetAutoreload(TIM1, TIMAutoreload);
TIM_ARRPreloadConfig(TIM1, ENABLE);
TIM_Cmd(TIM1, ENABLE);
TIM_CtrlPWMOutputs(TIM1, ENABLE);
}