diff --git a/targets/TARGET_TOSHIBA/TARGET_TMPM066/reset_reason_api.c b/targets/TARGET_TOSHIBA/TARGET_TMPM066/reset_reason_api.c
new file mode 100644
index 0000000000..f5bd6230ce
--- /dev/null
+++ b/targets/TARGET_TOSHIBA/TARGET_TMPM066/reset_reason_api.c
@@ -0,0 +1,123 @@
+/* mbed Microcontroller Library
+ * (C)Copyright TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION 2017 All rights reserved
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <stdbool.h>
+#include "reset_reason_api.h"
+#include "TMPM066.h"
+
+#define MAXRSTREASON        6
+
+static uint8_t set_bit_count(uint32_t reg);
+static uint8_t bit_pos(uint32_t reg);
+static bool bit_status(uint32_t reg, uint8_t bit_no);
+
+static reset_reason_t reset_reason1[MAXRSTREASON] = {
+    RESET_REASON_POWER_ON,
+    RESET_REASON_UNKNOWN,
+    RESET_REASON_UNKNOWN,
+    RESET_REASON_PIN_RESET,
+    RESET_REASON_UNKNOWN,
+    RESET_REASON_BROWN_OUT
+};
+
+static reset_reason_t reset_reason2[MAXRSTREASON] = {
+    RESET_REASON_SOFTWARE,
+    RESET_REASON_UNKNOWN,
+    RESET_REASON_WATCHDOG
+};
+
+void hal_reset_reason_clear(void)
+{
+    TSB_AOREG->RSTFLG  = 0x00;
+    TSB_AOREG->RSTFLG1 = 0x00;
+}
+
+uint32_t hal_reset_reason_get_raw(void)
+{
+    uint32_t ret = 0x00;
+
+    ret = (((TSB_AOREG->RSTFLG1 & 0xFF) << 8) | (TSB_AOREG->RSTFLG & 0xFF));
+
+    return ret;
+}
+
+reset_reason_t hal_reset_reason_get(void)
+{
+    reset_reason_t ret;
+
+    uint8_t NoOfSetBitCountReg1 = set_bit_count(TSB_AOREG->RSTFLG);
+    uint8_t NoOfSetBitCountReg2 = set_bit_count(TSB_AOREG->RSTFLG1);
+
+    if (NoOfSetBitCountReg1 != 0x00) {
+        if (NoOfSetBitCountReg1 > 0x01) {
+            if (bit_status(TSB_AOREG->RSTFLG, 0) && bit_status(TSB_AOREG->RSTFLG, 3)) {
+                ret = RESET_REASON_POWER_ON;
+            } else {
+                ret = RESET_REASON_MULTIPLE;
+            }
+        } else {
+            ret = reset_reason1[bit_pos(TSB_AOREG->RSTFLG)];
+        }
+    } else if (NoOfSetBitCountReg2 != 0x00) {
+        if (NoOfSetBitCountReg2 > 0x01) {
+            ret = RESET_REASON_MULTIPLE;
+        } else {
+            ret = reset_reason2[bit_pos(TSB_AOREG->RSTFLG1)];
+        }
+    } else {
+        ret = RESET_REASON_UNKNOWN;
+    }
+
+    return ret;
+}
+
+static bool bit_status(uint32_t reg, uint8_t bit_no)
+{
+    bool status = false;
+
+    if (reg & (1 << bit_no)) {
+        status = true;
+    }
+
+    return status;
+}
+
+static uint8_t set_bit_count(uint32_t reg)
+{
+    uint8_t count = 0;
+    int8_t index  = 0;
+
+    for (index = 0; index < (sizeof(uint32_t) * 8); index++) {
+        if (reg & (1 << index)) {
+            count++;
+            if (count > 0x01) {
+                break;
+            }
+        }
+    }
+
+    return count;
+}
+
+static uint8_t bit_pos(uint32_t reg)
+{
+    uint8_t bit_no = 0;
+
+    for (bit_no = 0; bit_no < (sizeof(uint32_t) * 8); bit_no++) {
+        if (reg & (1 << bit_no)) {
+            return bit_no;
+        }
+    }
+}
diff --git a/targets/TARGET_TOSHIBA/TARGET_TMPM46B/reset_reason_api.c b/targets/TARGET_TOSHIBA/TARGET_TMPM46B/reset_reason_api.c
new file mode 100644
index 0000000000..af94dc4f55
--- /dev/null
+++ b/targets/TARGET_TOSHIBA/TARGET_TMPM46B/reset_reason_api.c
@@ -0,0 +1,89 @@
+/* mbed Microcontroller Library
+ * (C)Copyright TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION 2018 All rights reserved
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <stdbool.h>
+#include "reset_reason_api.h"
+#include "TMPM46B.h"
+
+static uint8_t set_bit_count(uint32_t reg);
+static uint8_t bit_pos(uint32_t reg);
+
+static reset_reason_t reset_reason[7] = {
+    RESET_REASON_PIN_RESET,
+    RESET_REASON_UNKNOWN,
+    RESET_REASON_WATCHDOG,
+    RESET_REASON_WAKE_LOW_POWER,
+    RESET_REASON_SOFTWARE,
+    RESET_REASON_UNKNOWN,
+    RESET_REASON_BROWN_OUT
+};
+
+void hal_reset_reason_clear(void)
+{
+    TSB_CG->RSTFLG = 0x00;
+}
+
+uint32_t hal_reset_reason_get_raw(void)
+{
+    uint32_t ret = 0;
+
+    ret = TSB_CG->RSTFLG;
+
+    return ret;
+}
+
+reset_reason_t hal_reset_reason_get(void)
+{
+    reset_reason_t ret;
+
+    uint8_t NoOfSetBitCountReg = set_bit_count(TSB_CG->RSTFLG);
+
+    if (NoOfSetBitCountReg != 0x00) {
+        if (NoOfSetBitCountReg > 0x01) {
+            ret = RESET_REASON_MULTIPLE;
+        } else {
+            ret = reset_reason[bit_pos(TSB_CG->RSTFLG)];
+        }
+    } else {
+        ret = RESET_REASON_UNKNOWN;
+    }
+
+    return ret;
+}
+
+static uint8_t set_bit_count(uint32_t reg)
+{
+    uint8_t count = 0;
+    int8_t index = 0;
+
+    for (index = 0; index < (sizeof(uint32_t) * 8); index++) {
+        if ((reg & (1 << index)) && index != 1) {
+            count++;
+        }
+    }
+
+    return count;
+}
+
+static uint8_t bit_pos(uint32_t reg)
+{
+    uint8_t bit_no = 0;
+
+    for (bit_no = 0; bit_no < (sizeof(uint32_t) * 8); bit_no++) {
+        if ((reg & (1 << bit_no)) && bit_no != 1) {
+            return bit_no;
+        }
+    }
+}
diff --git a/targets/targets.json b/targets/targets.json
index 27cb3049e9..239db5f26b 100644
--- a/targets/targets.json
+++ b/targets/targets.json
@@ -7991,6 +7991,7 @@
             "PORTIN",
             "PORTINOUT",
             "PORTOUT",
+            "RESET_REASON",
             "SERIAL",
             "SLEEP",
             "I2C",
@@ -8054,6 +8055,7 @@
             "PORTINOUT",
             "PORTOUT",
             "PWMOUT",
+            "RESET_REASON",
             "SERIAL",
             "SERIAL_FC",
             "SPI",