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+.. highlight:: c
+.. _libmaple-iwdg:
+
+``<libmaple/iwdg.h>``
+=====================
+
+Independent Watchdog (IWDG) support. The IWDG peripheral is common
+across supported targets, so everything documented here is portable.
+
+.. contents:: Contents
+   :local:
+
+Usage Note
+----------
+
+To use the independent watchdog, first call :ref:`iwdg_init()
+<libmaple-iwdg-iwdg_init>` with the appropriate prescaler and IWDG
+counter reload values for your application.  Afterwards, you must
+periodically call :ref:`iwdg_feed() <libmaple-iwdg-iwdg_feed>` before
+the IWDG counter reaches zero to reset the counter to its reload
+value.  If you do not, the chip will reset.
+
+Once started, the independent watchdog cannot be turned off.
+
+Devices
+-------
+
+None at this time.
+
+Functions
+---------
+
+.. _libmaple-iwdg-iwdg_init:
+.. doxygenfunction:: iwdg_init
+.. _libmaple-iwdg-iwdg_feed:
+.. doxygenfunction:: iwdg_feed
+
+Types
+-----
+
+.. doxygenenum:: iwdg_prescaler
+
+
+Register Maps
+-------------
+
+.. doxygendefine:: IWDG_BASE
+
+.. doxygenstruct:: iwdg_reg_map
+
+Register Bit Definitions
+------------------------
+
+These are given as source code.
+
+::
+
+    /* Key register */
+
+    #define IWDG_KR_UNLOCK                  0x5555
+    #define IWDG_KR_FEED                    0xAAAA
+    #define IWDG_KR_START                   0xCCCC
+
+    /* Prescaler register */
+
+    #define IWDG_PR_DIV_4                   0x0
+    #define IWDG_PR_DIV_8                   0x1
+    #define IWDG_PR_DIV_16                  0x2
+    #define IWDG_PR_DIV_32                  0x3
+    #define IWDG_PR_DIV_64                  0x4
+    #define IWDG_PR_DIV_128                 0x5
+    #define IWDG_PR_DIV_256                 0x6
+
+    /* Status register */
+
+    #define IWDG_SR_RVU_BIT                 1
+    #define IWDG_SR_PVU_BIT                 0
+
+    #define IWDG_SR_RVU                     (1U << IWDG_SR_RVU_BIT)
+    #define IWDG_SR_PVU                     (1U << IWDG_SR_PVU_BIT)