diff --git a/components/drivers/hwtimer/hwtimer.c b/components/drivers/hwtimer/hwtimer.c
index cd85b3baefca170b8278863bbaf90d7e83262d69..83a76c7b9d8e31dde95e47a8bfed576d8ebef2ab 100644
--- a/components/drivers/hwtimer/hwtimer.c
+++ b/components/drivers/hwtimer/hwtimer.c
@@ -153,7 +153,7 @@ static rt_size_t rt_hwtimer_read(struct rt_device *dev, rt_off_t pos, void *buff
     cnt = timer->ops->count_get(timer);
     if (timer->info->cntmode == HWTIMER_CNTMODE_DW)
     {
-        cnt = timer->info->maxcnt - cnt;
+        cnt = (timer->freq * timer->period_sec) - cnt;
     }
 
     t = timer->overflow * timer->period_sec + cnt/(float)timer->freq;