GD32F427的脉冲计数功能（采用外部ETI配置）

中断可去除。

void ETI_gpio_config(void)
{
    rcu_periph_clock_enable(RCU_GPIOE);
    rcu_periph_clock_enable(RCU_GPIOD);

    /*configure PE7(TIMER0_ETI) as alternate function*/
    gpio_mode_set(GPIOE, GPIO_MODE_AF, GPIO_PUPD_PULLDOWN, GPIO_PIN_7);
    gpio_output_options_set(GPIOE, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ,GPIO_PIN_7);
    gpio_af_set(GPIOE, GPIO_AF_1, GPIO_PIN_7);
    gpio_bit_reset(GPIOE, GPIO_PIN_7);

    /*configure PD2(TIMER2_ETI) as alternate function*/
    gpio_mode_set(GPIOD, GPIO_MODE_AF, GPIO_PUPD_PULLDOWN, GPIO_PIN_2);
    gpio_output_options_set(GPIOD, GPIO_OTYPE_PP, GPIO_OSPEED_50MHZ,GPIO_PIN_2);
    gpio_af_set(GPIOD, GPIO_AF_2, GPIO_PIN_2);
    gpio_bit_reset(GPIOD, GPIO_PIN_2);
}

//脉冲计数定时器初始化TIMER0 TIMER2
void ETI_timer_config(void)
{
    timer_parameter_struct    timer_initpara;

    /* 使能 TIMER0 TIMER2 外设时钟 */
    rcu_periph_clock_enable(RCU_TIMER0);
    rcu_periph_clock_enable(RCU_TIMER2);

    /* 配置定时器时钟为CK_AHB总线时钟 */
    rcu_timer_clock_prescaler_config(RCU_TIMER_PSC_MUL4);

    /*复位定时器 TIMER0 TIMER2 */
    timer_deinit(TIMER0);
    timer_deinit(TIMER2);

    /* TIMER0 TIMER2 parameter configuration */
    timer_initpara.prescaler         = 0;
    timer_initpara.alignedmode       = TIMER_COUNTER_EDGE;
    timer_initpara.counterdirection  = TIMER_COUNTER_UP;
    timer_initpara.period            = 0x100;
    timer_initpara.clockdivision     = TIMER_CKDIV_DIV1;
    timer_initpara.repetitioncounter = 0;
    timer_init(TIMER0,&timer_initpara);
    timer_init(TIMER2,&timer_initpara);

    //如果外部时钟模式 0 和外部时钟模式 1 同时被配置，外部时钟的输入是 ETIF
    /* 定时器从模式选择 */
    timer_slave_mode_select(TIMER0,TIMER_SLAVE_MODE_EXTERNAL0);
    timer_slave_mode_select(TIMER2,TIMER_SLAVE_MODE_EXTERNAL0);

    /* 从模式配置寄存器(TIMERx_SMCFG) TRGS[2:0] 用来指定选择哪一个信号作为用来同步计数器的触发输入源 */
    timer_input_trigger_source_select(TIMER0, TIMER_SMCFG_TRGSEL_ETIFP);
    timer_input_trigger_source_select(TIMER2, TIMER_SMCFG_TRGSEL_ETIFP);

    /* 从模式配置寄存器(TIMERx_SMCFG[14]) SMC1 从模式控制=>外部时钟模式1配置 */
    timer_external_clock_mode1_config(TIMER0, TIMER_EXT_TRI_PSC_OFF, TIMER_ETP_RISING, 0X0);
    timer_external_clock_mode1_config(TIMER2, TIMER_EXT_TRI_PSC_OFF, TIMER_ETP_RISING, 0X0);

    /* 使能定时器主-从模式 */
    timer_master_slave_mode_config(TIMER0, TIMER_MASTER_SLAVE_MODE_ENABLE);
    timer_master_slave_mode_config(TIMER2, TIMER_MASTER_SLAVE_MODE_ENABLE);

    /* 清空定时器计数值 */
    timer_counter_value_config(TIMER0, 0);
    timer_counter_value_config(TIMER2, 0);

    /* NVIC 中断组选择 */
    nvic_priority_group_set(NVIC_PRIGROUP_PRE1_SUB3);

    /* 清除中断标志位 */
    timer_interrupt_flag_clear(TIMER0, TIMER_INT_FLAG_UP);
    timer_interrupt_flag_clear(TIMER2, TIMER_INT_FLAG_UP);

    /* NVIC 中断配置 */
    nvic_irq_enable(TIMER0_TRG_CMT_TIMER10_IRQn, 0, 0);
    nvic_irq_enable(TIMER2_IRQn, 0, 0);

    /* 使能中断标志位 */
    timer_interrupt_enable(TIMER0, TIMER_INT_UP);
    timer_interrupt_enable(TIMER2, TIMER_INT_UP);

    /* 使能定时器 */
    timer_enable(TIMER0);
    timer_enable(TIMER2);
}

void TIMER0_TRG_CMT_TIMER10_IRQHandler(void)
{
    if (SET == timer_interrupt_flag_get(TIMER0, TIMER_INT_FLAG_UP))
    {
        /* 清除更新中断标志 */
        timer_interrupt_flag_clear(TIMER0, TIMER_INT_FLAG_UP);
    }
}

void TIMER2_IRQHandler(void)
{
    if (SET == timer_interrupt_flag_get(TIMER2, TIMER_INT_FLAG_UP))
    {
        /* 清除更新中断标志 */
        timer_interrupt_flag_clear(TIMER2, TIMER_INT_FLAG_UP);
    }

}

int ETI_FUNC(void)
{
    ETI_gpio_config();
    ETI_timer_config();

    while(1)
    {
        delay_1ms(100);
        printf("TIMER0 cnt = 0x%x ,dir %d\r\n",TIMER_CNT(TIMER0),(TIMER_CTL0(TIMER0)&TIMER_CTL0_DIR)==TIMER_CTL0_DIR);
        printf("TIMER2 cnt = 0x%x ,dir %d\r\n",TIMER_CNT(TIMER2),(TIMER_CTL0(TIMER2)&TIMER_CTL0_DIR)==TIMER_CTL0_DIR);
    }
}