diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/TARGET_NUMAKER_PFM_M2351/PeripheralNames.h b/targets/TARGET_NUVOTON/TARGET_M2351/TARGET_NUMAKER_PFM_M2351/PeripheralNames.h
index 03b39c9574..249008f8ed 100644
--- a/targets/TARGET_NUVOTON/TARGET_M2351/TARGET_NUMAKER_PFM_M2351/PeripheralNames.h
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/TARGET_NUMAKER_PFM_M2351/PeripheralNames.h
@@ -18,6 +18,7 @@
 #define MBED_PERIPHERALNAMES_H
 
 #include "cmsis.h"
+#include "partition_M2351.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -67,12 +68,36 @@ typedef enum {
 } ADCName;
 
 typedef enum {
+#if defined (SCU_INIT_PNSSET3_VAL) && (SCU_INIT_PNSSET3_VAL & (0x01<<16))
+    UART_0 = (int) NU_MODNAME(UART0_BASE + NS_OFFSET, 0, 0),
+#else
     UART_0 = (int) NU_MODNAME(UART0_BASE, 0, 0),
+#endif    
+#if defined (SCU_INIT_PNSSET3_VAL) && (SCU_INIT_PNSSET3_VAL & (0x01<<17))
+    UART_1 = (int) NU_MODNAME(UART1_BASE + NS_OFFSET, 1, 0),
+#else
     UART_1 = (int) NU_MODNAME(UART1_BASE, 1, 0),
+#endif
+#if defined (SCU_INIT_PNSSET3_VAL) && (SCU_INIT_PNSSET3_VAL & (0x01<<18))
+    UART_2 = (int) NU_MODNAME(UART2_BASE + NS_OFFSET, 2, 0),
+#else    
     UART_2 = (int) NU_MODNAME(UART2_BASE, 2, 0),
+#endif
+#if defined (SCU_INIT_PNSSET3_VAL) && (SCU_INIT_PNSSET3_VAL & (0x01<<19))
+    UART_3 = (int) NU_MODNAME(UART3_BASE + NS_OFFSET, 3, 0),
+#else
     UART_3 = (int) NU_MODNAME(UART3_BASE, 3, 0),
+#endif    
+#if defined (SCU_INIT_PNSSET3_VAL) && (SCU_INIT_PNSSET3_VAL & (0x01<<20))
+    UART_4 = (int) NU_MODNAME(UART4_BASE + NS_OFFSET, 4, 0),
+#else
     UART_4 = (int) NU_MODNAME(UART4_BASE, 4, 0),
-    UART_5 = (int) NU_MODNAME((UART5_BASE + NS_OFFSET), 5, 0),  // UART 5 is the stdio, set as non-secure
+#endif
+#if defined (SCU_INIT_PNSSET3_VAL) && (SCU_INIT_PNSSET3_VAL & (0x01<<21))
+    UART_5 = (int) NU_MODNAME(UART5_BASE + NS_OFFSET, 5, 0),
+#else
+    UART_5 = (int) NU_MODNAME(UART5_BASE, 5, 0),
+#endif    
     // NOTE: board-specific
     STDIO_UART  = UART_3
 } UARTName;
@@ -124,10 +149,16 @@ typedef enum {
 } PWMName;
 
 typedef enum {
-    TIMER_0  = (int) NU_MODNAME(TMR01_BASE + NS_OFFSET, 0, 0),
-    TIMER_1  = (int) NU_MODNAME(TMR01_BASE + NS_OFFSET + 0x100, 1, 0),
+// TIME 0 & TIME 1 only support secure mode
+    TIMER_0  = (int) NU_MODNAME(TMR01_BASE, 0, 0),
+    TIMER_1  = (int) NU_MODNAME(TMR01_BASE + 0x100, 1, 0),
+#if defined (SCU_INIT_PNSSET2_VAL) && (SCU_INIT_PNSSET2_VAL & (0x01<<17))
     TIMER_2  = (int) NU_MODNAME(TMR23_BASE + NS_OFFSET, 2, 0),
     TIMER_3  = (int) NU_MODNAME(TMR23_BASE + NS_OFFSET + 0x100, 3, 0),
+#else
+    TIMER_2  = (int) NU_MODNAME(TMR23_BASE, 2, 0),
+    TIMER_3  = (int) NU_MODNAME(TMR23_BASE + 0x100, 3, 0),
+#endif    
 } TIMERName;
 
 typedef enum {
diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/device/M2351.h b/targets/TARGET_NUVOTON/TARGET_M2351/device/M2351.h
index 8f57793c68..00c1b00d7b 100644
--- a/targets/TARGET_NUVOTON/TARGET_M2351/device/M2351.h
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/device/M2351.h
@@ -31226,11 +31226,7 @@ typedef struct
 /* Peripheral and SRAM base address */
 #define SRAM_BASE            (0x20000000UL)                              /*!< (SRAM      ) Base Address */
 #define NS_OFFSET            (0x10000000UL)
-#if (__DOMAIN_NS == 1U)
-#define PERIPH_BASE          (0x40000000UL + NS_OFFSET)                              /*!< (Peripheral) Base Address */
-#else
 #define PERIPH_BASE          (0x40000000UL)                              /*!< (Peripheral) Base Address */
-#endif
 
 /* Peripheral memory map */
 #define AHBPERIPH_BASE       PERIPH_BASE
diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/device/TOOLCHAIN_GCC_ARM/M2351.ld b/targets/TARGET_NUVOTON/TARGET_M2351/device/TOOLCHAIN_GCC_ARM/M2351.ld
index 52d672af24..db73947cda 100644
--- a/targets/TARGET_NUVOTON/TARGET_M2351/device/TOOLCHAIN_GCC_ARM/M2351.ld
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/device/TOOLCHAIN_GCC_ARM/M2351.ld
@@ -263,10 +263,9 @@ SECTIONS
         __end__ = .;
         end = __end__;
         *(.heap*);
+        . += (ORIGIN(RAM_INTERN) + LENGTH(RAM_INTERN) - .);        
         __HeapLimit = .;
     } > RAM_INTERN
-
-    __HeapLimit = ORIGIN(RAM_INTERN) + LENGTH(RAM_INTERN);    
     
     PROVIDE(__heap_size = SIZEOF(.heap));
     PROVIDE(__mbed_sbrk_start = ADDR(.heap));
diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/device/partition_M2351.h b/targets/TARGET_NUVOTON/TARGET_M2351/device/partition_M2351.h
index 0c49636bdf..028d003b85 100644
--- a/targets/TARGET_NUVOTON/TARGET_M2351/device/partition_M2351.h
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/device/partition_M2351.h
@@ -367,7 +367,7 @@
 
 //
 */
-#define NVIC_INIT_ITNS1_VAL      0x0F
+#define NVIC_INIT_ITNS1_VAL      0x0C
 
 /*
     Initialize ITNS 2 (Interrupts 0..31)
@@ -432,7 +432,7 @@
 */
 
 
-
+#if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
 /*
     max 128 SAU regions.
     SAU regions are defined in partition.h
@@ -539,7 +539,7 @@ __STATIC_INLINE void TZ_SAU_Setup(void)
     /* repeat this for all possible ITNS elements */
 
 }
-
+#endif
 
 /*
 // <h> Peripheral Secure Attribution Configuration
@@ -584,7 +584,7 @@ __STATIC_INLINE void TZ_SAU_Setup(void)
 //   <o.26>  BPWM0      <0=> Secure <1=> Non-Secure
 //   <o.27>  BPWM1      <0=> Secure <1=> Non-Secure
 */
-#define SCU_INIT_PNSSET2_VAL      0x00000002
+#define SCU_INIT_PNSSET2_VAL      0x00020002
 /*
     PNSSET3
 */
diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/gpio_object.h b/targets/TARGET_NUVOTON/TARGET_M2351/gpio_object.h
index 92268e43e6..7987b3ebad 100644
--- a/targets/TARGET_NUVOTON/TARGET_M2351/gpio_object.h
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/gpio_object.h
@@ -22,6 +22,7 @@
 #include "PortNames.h"
 #include "PeripheralNames.h"
 #include "PinNames.h"
+#include "partition_M2351.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -37,8 +38,16 @@ static inline void gpio_write(gpio_t *obj, int value)
     MBED_ASSERT(obj->pin != (PinName)NC);    
     uint32_t pin_index = NU_PINNAME_TO_PIN(obj->pin);
     uint32_t port_index = NU_PINNAME_TO_PORT(obj->pin);
-    
-    GPIO_PIN_DATA(port_index, pin_index) = value ? 1 : 0;
+#if defined (NVIC_INIT_ITNS0_VAL)
+    if( NVIC_INIT_ITNS0_VAL & (0x01 << (16 + port_index)) )
+		{
+			GPIO_PIN_DATA_NS(port_index, pin_index) = value ? 1 : 0;
+		} else {
+			GPIO_PIN_DATA(port_index, pin_index) = value ? 1 : 0;
+		}
+#else
+        GPIO_PIN_DATA(port_index, pin_index) = value ? 1 : 0;
+#endif
 }
 
 static inline int gpio_read(gpio_t *obj)
@@ -46,8 +55,16 @@ static inline int gpio_read(gpio_t *obj)
     MBED_ASSERT(obj->pin != (PinName)NC);
     uint32_t pin_index = NU_PINNAME_TO_PIN(obj->pin);
     uint32_t port_index = NU_PINNAME_TO_PORT(obj->pin);
-    
-    return (GPIO_PIN_DATA(port_index, pin_index) ? 1 : 0);
+#if defined (NVIC_INIT_ITNS0_VAL)
+    if( NVIC_INIT_ITNS0_VAL & (0x01 << (16 + port_index)) )
+		{    
+			return (GPIO_PIN_DATA_NS(port_index, pin_index) ? 1 : 0);			
+		} else {	
+			return (GPIO_PIN_DATA(port_index, pin_index) ? 1 : 0);
+		}	
+#else
+        return (GPIO_PIN_DATA(port_index, pin_index) ? 1 : 0);
+#endif
 }
 
 #ifdef __cplusplus
diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/lp_ticker.c b/targets/TARGET_NUVOTON/TARGET_M2351/lp_ticker.c
index 078bf8cddb..dbd500b3f6 100644
--- a/targets/TARGET_NUVOTON/TARGET_M2351/lp_ticker.c
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/lp_ticker.c
@@ -50,6 +50,8 @@ static const struct nu_modinit_s timer3_modinit = {TIMER_3, TMR3_MODULE, CLK_CLK
 #define TMR_CMP_MIN         2
 #define TMR_CMP_MAX         0xFFFFFFu
 
+#if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
+__attribute__((cmse_nonsecure_entry))
 void lp_ticker_init(void)
 {
     if (lp_ticker_inited) {
@@ -104,6 +106,7 @@ void lp_ticker_init(void)
     // Schedule wakeup to match semantics of lp_ticker_get_compare_match()
     lp_ticker_set_interrupt(wakeup_tick);
 }
+#endif
 
 timestamp_t lp_ticker_read()
 {    
diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/port_api.c b/targets/TARGET_NUVOTON/TARGET_M2351/port_api.c
index deadd80ec5..51584a7fb0 100644
--- a/targets/TARGET_NUVOTON/TARGET_M2351/port_api.c
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/port_api.c
@@ -18,6 +18,7 @@
 #include "gpio_api.h"
 #include "pinmap.h"
 #include "mbed_error.h"
+#include "partition_M2351.h"
 
 #if DEVICE_PORTIN || DEVICE_PORTOUT || DEVICE_PORTINOUT
 
@@ -79,7 +80,16 @@ void port_write(port_t *obj, int value)
     
     for (i = 0; i < GPIO_PIN_MAX; i++) {
         if (obj->mask & (1 << i)) {
+#if defined (NVIC_INIT_ITNS0_VAL)
+            if( NVIC_INIT_ITNS0_VAL & (0x01 << (16 + port_index)) )
+            {        
+                GPIO_PIN_DATA_NS(port_index, i) = (value & obj->mask) ? 1 : 0;
+             } else {
+                GPIO_PIN_DATA(port_index, i) = (value & obj->mask) ? 1 : 0;
+             }
+#else
             GPIO_PIN_DATA(port_index, i) = (value & obj->mask) ? 1 : 0;
+#endif             
         }
     }
 }
@@ -92,7 +102,16 @@ int port_read(port_t *obj)
     
     for (i = 0; i < GPIO_PIN_MAX; i++) {
         if (obj->mask & (1 << i)) {
+#if defined (NVIC_INIT_ITNS0_VAL)
+            if( NVIC_INIT_ITNS0_VAL & (0x01 << (16 + port_index)) )
+            {         
+                value = value | (GPIO_PIN_DATA_NS(port_index, i) << i);
+            } else {
+                value = value | (GPIO_PIN_DATA(port_index, i) << i);
+            }
+#else
             value = value | (GPIO_PIN_DATA(port_index, i) << i);
+#endif
         }
     }
     
diff --git a/targets/TARGET_NUVOTON/TARGET_M2351/us_ticker.c b/targets/TARGET_NUVOTON/TARGET_M2351/us_ticker.c
index adeab67139..ea8f89f5df 100644
--- a/targets/TARGET_NUVOTON/TARGET_M2351/us_ticker.c
+++ b/targets/TARGET_NUVOTON/TARGET_M2351/us_ticker.c
@@ -21,6 +21,7 @@
 #include "nu_miscutil.h"
 #include "mbed_critical.h"
 
+
 // us_ticker tick = us = timestamp
 #define US_PER_TICK             1
 #define US_PER_SEC              (1000 * 1000)
@@ -50,13 +51,15 @@ static volatile uint32_t cd_minor_us = 0;
 //       2. HXT: Less accurate and cannot pass mbed-drivers test.
 //       3. PCLK(HXT): Less accurate but can pass mbed-drivers test.
 // NOTE: TIMER_0 for normal counter, TIMER_1 for countdown.
+
 static const struct nu_modinit_s timer0hires_modinit = {TIMER_0, TMR0_MODULE, CLK_CLKSEL1_TMR0SEL_PCLK0, 0, TMR0_RST, TMR0_IRQn, (void *) tmr0_vec};
 static const struct nu_modinit_s timer1hires_modinit = {TIMER_1, TMR1_MODULE, CLK_CLKSEL1_TMR1SEL_PCLK0, 0, TMR1_RST, TMR1_IRQn, (void *) tmr1_vec};
 
 #define TMR_CMP_MIN         2
 #define TMR_CMP_MAX         0xFFFFFFu
 
-
+#if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
+__attribute__((cmse_nonsecure_entry))
 void us_ticker_init(void)
 {
     if (us_ticker_inited) {
@@ -100,7 +103,10 @@ void us_ticker_init(void)
     TIMER_Start((TIMER_T *) NU_MODBASE(timer0hires_modinit.modname));
 
 }
+#endif
 
+#if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
+__attribute__((cmse_nonsecure_entry))
 uint32_t us_ticker_read()
 {
     if (! us_ticker_inited) {
@@ -138,17 +144,22 @@ uint32_t us_ticker_read()
     }
     while (0);
 }
+#endif
 
+#if defined (__ARM_FEATURE_CMSE) && (__ARM_FEATURE_CMSE == 3U)
+__attribute__((cmse_nonsecure_entry))
 void us_ticker_disable_interrupt(void)
 {
     TIMER_DisableInt((TIMER_T *) NU_MODBASE(timer1hires_modinit.modname));
 }
 
+__attribute__((cmse_nonsecure_entry))
 void us_ticker_clear_interrupt(void)
 {
     TIMER_ClearIntFlag((TIMER_T *) NU_MODBASE(timer1hires_modinit.modname));
 }
 
+__attribute__((cmse_nonsecure_entry))
 void us_ticker_set_interrupt(timestamp_t timestamp)
 {
     TIMER_Stop((TIMER_T *) NU_MODBASE(timer1hires_modinit.modname));
@@ -158,6 +169,7 @@ void us_ticker_set_interrupt(timestamp_t timestamp)
     us_ticker_arm_cd();
 }
 
+__attribute__((cmse_nonsecure_entry))
 void us_ticker_fire_interrupt(void)
 {
     cd_major_minor_us = cd_minor_us = 0;
@@ -167,6 +179,7 @@ void us_ticker_fire_interrupt(void)
      */
     NVIC_SetPendingIRQ(timer1hires_modinit.irq_n);
 }
+#endif
 
 static void tmr0_vec(void)
 {