DA14531硬件定时器使用问题

请问DA14531的硬件定时器Timer0最小可以定时多久呢，我想定时1us进一次中断，但是实际测试发现进行IO翻转时，高电平1.8-2us，低电平2.2-2.4us.我的设置是这样的：

static tim0_2_clk_div_config_t clk_div_config =
{
.clk_div = TIM0_2_CLK_DIV_1 // 16MHZ/1
};

void timer0_general_user_callback_function(void)
{
if((GetWord16(GPIO_BASE + (GPIO_LED_PORT << 5)) & (1 << GPIO_LED_PIN)))
SetWord16 (GPIO_BASE + (GPIO_LED_PORT < < 5) + 4, 1<< GPIO_LED_PIN); //low
else if((GetWord16(GPIO_BASE + (GPIO_LED_PORT << 5)) & (1 << GPIO_LED_PIN))==0)
SetWord16(GPIO_BASE + (GPIO_LED_PORT << 5) + 2 , 1 << GPIO_LED_PIN); //High
}

void timer0_Interrupt_Init(uint16_t RELOAD_1US)
{
// Stop timer for enter settings
timer0_stop();

// register callback function for SWTIM_IRQn irq
timer0_register_callback(timer0_general_user_callback_function);

// Enable the Timer0/Timer2 input clock
timer0_2_clk_enable();

// Set the Timer0/Timer2 input clock division factor to 8, so 16 MHz / 1 = 16 MHz input clock
timer0_2_clk_div_set(&clk_div_config);

// clear PWM settings register to not generate PWM
timer0_set_pwm_high_counter(NO_PWM); //TIMER0_RELOAD_M_REG = 0
timer0_set_pwm_low_counter(NO_PWM); //TIMER0_RELOAD_N_REG = 0

// Set timer with 2MHz source clock divided by 10 so Fclk = 16MHz/1 = 16MHz
timer0_init(TIM0_CLK_FAST, PWM_MODE_ONE, TIM0_CLK_NO_DIV);

// T = 1/16MHz * (RELOAD_100US+1) =0.0000000625 * 16 = 1us RELOAD_100US = 16
timer0_set_pwm_on_counter(RELOAD_1US); //TIMER0_ON_REG = 1600

// Enable SWTIM_IRQn irq
timer0_enable_irq();

// Start Timer0
timer0_start();
}

是哪里存在问题吗？请问如何才能精准的1us进一次中断呢

期待回复，非常感谢