diff --git a/targets/TARGET_NUVOTON/TARGET_M251/pwmout_api.c b/targets/TARGET_NUVOTON/TARGET_M251/pwmout_api.c
index eec6974f4f..34798e4d1d 100644
--- a/targets/TARGET_NUVOTON/TARGET_M251/pwmout_api.c
+++ b/targets/TARGET_NUVOTON/TARGET_M251/pwmout_api.c
@@ -59,9 +59,9 @@ static const struct nu_modinit_s pwm_modinit_tab[] = {
     {NC, 0, 0, 0, 0, (IRQn_Type) 0, NULL}
 };
 
-static void pwmout_config(pwmout_t* obj, int start);
+static void pwmout_config(pwmout_t *obj, int start);
 
-void pwmout_init(pwmout_t* obj, PinName pin)
+void pwmout_init(pwmout_t *obj, PinName pin)
 {
     obj->pwm = (PWMName) pinmap_peripheral(pin, PinMap_PWM);
     MBED_ASSERT((int) obj->pwm != NC);
@@ -86,7 +86,7 @@ void pwmout_init(pwmout_t* obj, PinName pin)
     }
 
     // NOTE: All channels (identified by PWMName) share a PWM module. This reset will also affect other channels of the same PWM module.
-    if (! ((struct nu_pwm_var *) modinit->var)->en_msk) {
+    if (!((struct nu_pwm_var *) modinit->var)->en_msk) {
         // Reset this module if no channel enabled
         SYS_ResetModule(modinit->rsetidx);
     }
@@ -103,7 +103,7 @@ void pwmout_init(pwmout_t* obj, PinName pin)
     pwm_modinit_mask |= 1 << i;
 }
 
-void pwmout_free(pwmout_t* obj)
+void pwmout_free(pwmout_t *obj)
 {
     PWM_T *pwm_base = (PWM_T *) NU_MODBASE(obj->pwm);
     uint32_t chn =  NU_MODSUBINDEX(obj->pwm);
@@ -128,29 +128,29 @@ void pwmout_free(pwmout_t* obj)
     obj->pin = NC;
 }
 
-void pwmout_write(pwmout_t* obj, float value)
+void pwmout_write(pwmout_t *obj, float value)
 {
-    obj->pulsewidth_us = NU_CLAMP((uint32_t) (value * obj->period_us), 0, obj->period_us);
+    obj->pulsewidth_us = NU_CLAMP((uint32_t)(value * obj->period_us), 0, obj->period_us);
     pwmout_config(obj, 1);
 }
 
-float pwmout_read(pwmout_t* obj)
+float pwmout_read(pwmout_t *obj)
 {
     return NU_CLAMP((((float) obj->pulsewidth_us) / obj->period_us), 0.0f, 1.0f);
 }
 
-void pwmout_period(pwmout_t* obj, float seconds)
+void pwmout_period(pwmout_t *obj, float seconds)
 {
     pwmout_period_us(obj, seconds * 1000000.0f);
 }
 
-void pwmout_period_ms(pwmout_t* obj, int ms)
+void pwmout_period_ms(pwmout_t *obj, int ms)
 {
     pwmout_period_us(obj, ms * 1000);
 }
 
 // Set the PWM period, keeping the duty cycle the same.
-void pwmout_period_us(pwmout_t* obj, int us)
+void pwmout_period_us(pwmout_t *obj, int us)
 {
     uint32_t period_us_old = obj->period_us;
     uint32_t pulsewidth_us_old = obj->pulsewidth_us;
@@ -159,23 +159,32 @@ void pwmout_period_us(pwmout_t* obj, int us)
     pwmout_config(obj, 1);
 }
 
-void pwmout_pulsewidth(pwmout_t* obj, float seconds)
+int pwmout_read_period_us(pwmout_t *obj)
+{
+    return obj->period_us;
+}
+
+void pwmout_pulsewidth(pwmout_t *obj, float seconds)
 {
     pwmout_pulsewidth_us(obj, seconds * 1000000.0f);
 }
 
-void pwmout_pulsewidth_ms(pwmout_t* obj, int ms)
+void pwmout_pulsewidth_ms(pwmout_t *obj, int ms)
 {
     pwmout_pulsewidth_us(obj, ms * 1000);
 }
 
-void pwmout_pulsewidth_us(pwmout_t* obj, int us)
+void pwmout_pulsewidth_us(pwmout_t *obj, int us)
 {
     obj->pulsewidth_us = NU_CLAMP(us, 0, obj->period_us);
     pwmout_config(obj, 1);
 }
 
-static void pwmout_config(pwmout_t* obj, int start)
+int pwmout_read_pulsewidth_us(pwmout_t *obj {
+    return obj->pulsewidth_us;
+}
+
+static void pwmout_config(pwmout_t *obj, int start)
 {
     PWM_T *pwm_base = (PWM_T *) NU_MODBASE(obj->pwm);
     uint32_t chn = NU_MODSUBINDEX(obj->pwm);