diff --git a/targets/TARGET_NUVOTON/TARGET_NANO100/lp_ticker.c b/targets/TARGET_NUVOTON/TARGET_NANO100/lp_ticker.c
index f993d42a5b..87b67b5ba8 100644
--- a/targets/TARGET_NUVOTON/TARGET_NANO100/lp_ticker.c
+++ b/targets/TARGET_NUVOTON/TARGET_NANO100/lp_ticker.c
@@ -148,31 +148,23 @@ timestamp_t lp_ticker_read()
 
 void lp_ticker_set_interrupt(timestamp_t timestamp)
 {
-    uint32_t now = lp_ticker_read();
+    uint32_t delta = timestamp - lp_ticker_read();
     wakeup_tick = timestamp;
     
     TIMER_Stop((TIMER_T *) NU_MODBASE(timer3_modinit.modname));
-    
+    cd_major_minor_clks = (uint64_t) delta * US_PER_TICK * TMR3_CLK_PER_SEC / US_PER_SEC;
+    lp_ticker_arm_cd();
+
+}
+
+void lp_ticker_fire_interrupt(void)
+{
+    cd_major_minor_clks = cd_minor_clks = 0;
     /**
-     * NOTE: Scheduled alarm may go off incorrectly due to wrap around.
-     * Conditions in which delta is negative:
-     * 1. Wrap around
-     * 2. Newly scheduled alarm is behind now
-     */ 
-    //int delta = (timestamp > now) ? (timestamp - now) : (uint32_t) ((uint64_t) timestamp + 0xFFFFFFFFu - now);
-    int delta = (int) (timestamp - now);
-    if (delta > 0) {
-        cd_major_minor_clks = (uint64_t) delta * US_PER_TICK * TMR3_CLK_PER_SEC / US_PER_SEC;
-        lp_ticker_arm_cd();
-    }
-    else {
-        cd_major_minor_clks = cd_minor_clks = 0;
-        /**
-         * This event was in the past. Set the interrupt as pending, but don't process it here.
-         * This prevents a recurive loop under heavy load which can lead to a stack overflow.
-         */  
-        NVIC_SetPendingIRQ(timer3_modinit.irq_n);
-    }
+     * This event was in the past. Set the interrupt as pending, but don't process it here.
+     * This prevents a recurive loop under heavy load which can lead to a stack overflow.
+     */  
+    NVIC_SetPendingIRQ(timer3_modinit.irq_n);
 }
 
 void lp_ticker_disable_interrupt(void)
diff --git a/targets/TARGET_NUVOTON/TARGET_NANO100/us_ticker.c b/targets/TARGET_NUVOTON/TARGET_NANO100/us_ticker.c
index 46d1c2dc4d..e0915940f5 100644
--- a/targets/TARGET_NUVOTON/TARGET_NANO100/us_ticker.c
+++ b/targets/TARGET_NUVOTON/TARGET_NANO100/us_ticker.c
@@ -148,19 +148,15 @@ void us_ticker_set_interrupt(timestamp_t timestamp)
 {
     TIMER_Stop((TIMER_T *) NU_MODBASE(timer1hires_modinit.modname));
     
-    int delta = (int) (timestamp - us_ticker_read());
-    if (delta > 0) {
-        cd_major_minor_us = delta * US_PER_TICK;
-        us_ticker_arm_cd();
-    }
-    else {
-        cd_major_minor_us = cd_minor_us = 0;
-        /**
-         * This event was in the past. Set the interrupt as pending, but don't process it here.
-         * This prevents a recurive loop under heavy load which can lead to a stack overflow.
-         */  
-        NVIC_SetPendingIRQ(timer1hires_modinit.irq_n);
-    }
+    uint32_t delta = timestamp - us_ticker_read();
+    cd_major_minor_us = delta * US_PER_TICK;
+    us_ticker_arm_cd();
+}
+
+void us_ticker_fire_interrupt(void)
+{
+    cd_major_minor_us = cd_minor_us = 0;
+    NVIC_SetPendingIRQ(timer1hires_modinit.irq_n);
 }
 
 void TMR0_IRQHandler(void)