IAR软件，使用官方halt库

u32 g_counter = 0;      // 全局， jiffes 滴答时钟,时间计时器；

INTERRUPT_HANDLER(TIM3_UPD_OVF_TRG_BRK_USART3_TX_IRQHandler,21)// 计数器; 50ms 中断一次

{

//    disableInterrupts();    g_counter ++;

   TIM3_ClearITPendingBit(TIM3_IT_Update);

//    enableInterrupts();

}

#define  time_after(unknown,known)        ((long)(known) - (long)(unknown) < 0)

#define  time_before(unkonwn,known)       ((long)(unknown) - (long)(known) < 0)

#define  time_after_eq(unknown,known)     ((long)(unknown) - (long)(known) >= 0) //- - -

#define  time_before_eq(unknown,known)    ((long)(known) -(long)(unknown) >= 0)

extern u8 time3_has_start;

void SYS16M_time3_start(void)  

{

    //时钟配置

    CLK_PeripheralClockConfig(CLK_Peripheral_TIM3, ENABLE);

    //64分频，向上计数，每50ms定时中断一次

    TIM3_DeInit();

    TIM3_TimeBaseInit(TIM3_Prescaler_128, TIM3_CounterMode_Up, 6250); // 16M / 128 = 1/8M; (1/8M) / (1/50ms) = 6250

    TIM3_ARRPreloadConfig(ENABLE);

    TIM3_ITConfig(TIM3_IT_Update, ENABLE);

    TIM3_Cmd(ENABLE);

    time3_has_start = 1;

}

void SYS16M_time3_stop(void)  

{

    TIM3_Cmd(DISABLE);

    CLK_PeripheralClockConfig(CLK_Peripheral_TIM3, DISABLE);

    time3_has_start = 0;

}

u32 red_led_flash_time = 0;

void xxx_function(void)

{

    red_led_flash_time = 0;

    if(blue_led_flash_time == 0)

        blue_led_flash_time = g_counter;

    if(time_after(g_counter, blue_led_flash_time + ONE_SECOND))

        blue_led_on;

    else if(time_after(g_counter, blue_led_flash_time + TWO_SECOND))

        blue_led_off;

}