diff --git a/.vscode/launch.json b/.vscode/launch.json
index ee70253..8b95413 100644
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -6,7 +6,7 @@
     "configurations": [
         {
             "name": "(Windows) Launch",
-            "type": "cppvsdbg",
+            "type": "cppdbg",
             "request": "launch",
             "program": "${workspaceFolder}\\build\\LwLibPROJECT.exe",
             "miDebuggerPath": "c:\\msys64\\mingw64\\bin\\gdb.exe",
diff --git a/CHANGELOG.md b/CHANGELOG.md
index d307109..b34703f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,11 @@
 
 ## Develop
 
+## v2.0.0
+
+- Remove `len` parameter for regions definition. Affected functions: `lwmem_assignmem` and `lwmem_assignmem_ex`
+- Create separate branch for v1.x, for critical maintenance purpose only
+
 ## v1.6.0
 
 - Add option to define regions with array only, setting length to `0` by default
diff --git a/dev/VisualStudio/lwmem_opts.h b/dev/VisualStudio/lwmem_opts.h
index 0925a5f..a03fa48 100644
--- a/dev/VisualStudio/lwmem_opts.h
+++ b/dev/VisualStudio/lwmem_opts.h
@@ -29,7 +29,6 @@
  * This file is part of Lightweight dynamic memory manager library.
  *
  * Author:          Tilen MAJERLE <tilen@majerle.eu>
- * Version:         v1.6.0
  */
 #ifndef LWMEM_HDR_OPTS_H
 #define LWMEM_HDR_OPTS_H
diff --git a/docs/examples_src/example_minimal.c b/docs/examples_src/example_minimal.c
index d6948b0..3d80f07 100644
--- a/docs/examples_src/example_minimal.c
+++ b/docs/examples_src/example_minimal.c
@@ -12,7 +12,7 @@ lwmem_region_t regions[] = {
 
 /* Later in the initialization process */
 /* Assign regions for manager */
-lwmem_assignmem(regions, 0);
+lwmem_assignmem(regions);
 
 /* Usage in program... */
 
diff --git a/docs/examples_src/example_realloc_enlarge_full.c b/docs/examples_src/example_realloc_enlarge_full.c
index 121eae0..2cc8f74 100644
--- a/docs/examples_src/example_realloc_enlarge_full.c
+++ b/docs/examples_src/example_realloc_enlarge_full.c
@@ -20,7 +20,7 @@ main(void) {
         printf("Cannot allocate memory for regions for debug purpose!\r\n");
         return -1;
     }
-    lwmem_assignmem(regions_used, regions_count);
+    lwmem_assignmem(regions_used);
     printf("Manager is ready!\r\n");
     lwmem_debug_print(1, 1);
 
diff --git a/docs/examples_src/example_realloc_region.c b/docs/examples_src/example_realloc_region.c
index 201b6d7..cca1fad 100644
--- a/docs/examples_src/example_realloc_region.c
+++ b/docs/examples_src/example_realloc_region.c
@@ -9,10 +9,11 @@ static unsigned char region_mem[128];
 static
 lwmem_region_t regions[] = {
     /* Set start address and size of each region */
-    { region_mem, sizeof(region_mem) }
+    { region_mem, sizeof(region_mem) },
+    { NULL, 0 }
 };
 
 /* Later in the initialization process */
 /* Assign regions for manager */
-lwmem_assignmem(regions, sizeof(regions) / sizeof(regions[0]));
+lwmem_assignmem(regions);
 lwmem_debug_free();     /* This is debug function for sake of this example */
\ No newline at end of file
diff --git a/docs/examples_src/example_regions_definitions.c b/docs/examples_src/example_regions_definitions.c
index ec68105..6af4aba 100644
--- a/docs/examples_src/example_regions_definitions.c
+++ b/docs/examples_src/example_regions_definitions.c
@@ -1,8 +1,5 @@
 #include "lwmem/lwmem.h"
 
-/* Set to 1 to describe regions only with array */
-#define DESCRIBE_REGIONS_WITH_ARRAY_ONLY            1
-
 /*
  * \brief           Define regions for memory manager
  */
@@ -12,13 +9,11 @@ lwmem_region_t regions[] = {
     { (void *)0x10000000, 0x00001000 },
     { (void *)0xA0000000, 0x00008000 },
     { (void *)0xC0000000, 0x00008000 },
-#if DESCRIBE_REGIONS_WITH_ARRAY_ONLY
     { NULL, 0},
-#endif
 };
 
 /* Later in the initialization process */
 /* Assign regions for manager */
-lwmem_assignmem(regions, DESCRIBE_REGIONS_WITH_ARRAY_ONLY ? 0 : (sizeof(regions) / sizeof(regions[0])));
+lwmem_assignmem(regions);
 /* or */
-lwmem_assignmem_ex(NULL, regions, DESCRIBE_REGIONS_WITH_ARRAY_ONLY ? 0 : (sizeof(regions) / sizeof(regions[0])));
\ No newline at end of file
+lwmem_assignmem_ex(NULL, regions);
\ No newline at end of file
diff --git a/docs/examples_src/example_regions_definitions_custom.c b/docs/examples_src/example_regions_definitions_custom.c
index 7d90f60..4e1d4f0 100644
--- a/docs/examples_src/example_regions_definitions_custom.c
+++ b/docs/examples_src/example_regions_definitions_custom.c
@@ -15,8 +15,9 @@ lwmem_region_t regions[] = {
     { (void *)0x10000000, 0x00001000 },
     { (void *)0xA0000000, 0x00008000 },
     { (void *)0xC0000000, 0x00008000 },
+    { NULL, 0 }
 };
 
 /* Later in the initialization process */
 /* Assign regions for custom instance */
-lwmem_assignmem_ex(&lw_custom, regions, sizeof(regions) / sizeof(regions[0]));
\ No newline at end of file
+lwmem_assignmem_ex(&lw_custom, regions);
\ No newline at end of file
diff --git a/docs/user-manual/how-it-works.rst b/docs/user-manual/how-it-works.rst
index 540cf53..8b51dc2 100644
--- a/docs/user-manual/how-it-works.rst
+++ b/docs/user-manual/how-it-works.rst
@@ -16,10 +16,12 @@ For the sake of this understanding, application is using ``3`` regions
 * Region ``1`` memory starts at ``0x1000 0000`` and is ``0x0000 1000`` bytes long
 * Region ``2`` memory starts at ``0xA000 0000`` and is ``0x0000 8000`` bytes long
 * Region ``3`` memory starts at ``0xC000 0000`` and is ``0x0000 8000`` bytes long
+* Entry ``4`` indicates end of regions array descriptor 
 
 .. note::
     Total size of memory used by application for memory manager is ``0x0001 1000`` bytes or ``69 kB``.
     This is a sum of all ``3`` regions.
+    Last entry indicates end of regions with start address set as ``NULL`` and size as ``0``
 
 Example also assumes that:
 
@@ -36,11 +38,6 @@ First step is to define custom regions and assign them to memory manager.
 .. note::
     Order of regions must be lower address first. Regions must not overlap with their sizes.
 
-.. tip::
-    Regions could be defined with array descriptor only, where last entry must be set to `NULL` address and `0` size.
-    This is useful for dynamic length definition with single descriptor file/address.
-    It allows application to define regions by setting linker scripts when compiling the code.
-
 When calling :c:macro:`lwmem_assignmem`, manager prepares memory blocks and assigns default values.
 
 .. figure:: ../static/images/structure_default.svg
diff --git a/examples/stm32/lwmem_rtos_stm32l496_discovery/inc/lwmem_opts.h b/examples/stm32/lwmem_rtos_stm32l496_discovery/inc/lwmem_opts.h
index c193d5e..0f929f3 100644
--- a/examples/stm32/lwmem_rtos_stm32l496_discovery/inc/lwmem_opts.h
+++ b/examples/stm32/lwmem_rtos_stm32l496_discovery/inc/lwmem_opts.h
@@ -29,7 +29,6 @@
  * This file is part of LwMEM - Lightweight dynamic memory manager library.
  *
  * Author:          Tilen MAJERLE <tilen@majerle.eu>
- * Version:         v1.6.0
  */
 #ifndef LWMEM_HDR_OPTS_H
 #define LWMEM_HDR_OPTS_H
diff --git a/examples/stm32/lwmem_rtos_stm32l496_discovery/inc/main.h b/examples/stm32/lwmem_rtos_stm32l496_discovery/inc/main.h
index 2ef3d4a..4bff3ec 100644
--- a/examples/stm32/lwmem_rtos_stm32l496_discovery/inc/main.h
+++ b/examples/stm32/lwmem_rtos_stm32l496_discovery/inc/main.h
@@ -27,7 +27,6 @@
  * OTHER DEALINGS IN THE SOFTWARE.
  *
  * Author:          Tilen MAJERLE <tilen@majerle.eu>
- * Version:         v1.6.0
  */
 #ifndef __MAIN_H
 #define __MAIN_H
diff --git a/examples/stm32/lwmem_rtos_stm32l496_discovery/src/main.c b/examples/stm32/lwmem_rtos_stm32l496_discovery/src/main.c
index 962cb90..e36eb21 100644
--- a/examples/stm32/lwmem_rtos_stm32l496_discovery/src/main.c
+++ b/examples/stm32/lwmem_rtos_stm32l496_discovery/src/main.c
@@ -27,7 +27,6 @@
  * OTHER DEALINGS IN THE SOFTWARE.
  *
  * Author:          Tilen MAJERLE <tilen@majerle.eu>
- * Version:         v1.6.0
  */
 #include "main.h"
 #include "cmsis_os.h"
@@ -49,6 +48,7 @@ static lwmem_region_t
 regions[] = {
     { region1_data, sizeof(region1_data) },
     /* Add more regions if needed */
+    { NULL, 0 }
 };
 
 static void app_thread(void* arg);
@@ -68,7 +68,7 @@ main(void) {
 
     /* Initialize LwMEM */
     printf("Initializing LwMEM...\r\n");
-    if (!lwmem_assignmem(regions, sizeof(regions) / sizeof(regions[0]))) {
+    if (!lwmem_assignmem(regions)) {
         printf("Cannot initialize LwMEM. Make sure your regions are not overlapping each other and are in ascending memory order\r\n");
         while (1) {}
     } else {
diff --git a/examples/stm32/lwmem_stm32l496_discovery/inc/lwmem_opts.h b/examples/stm32/lwmem_stm32l496_discovery/inc/lwmem_opts.h
index 2f031ac..1f94312 100644
--- a/examples/stm32/lwmem_stm32l496_discovery/inc/lwmem_opts.h
+++ b/examples/stm32/lwmem_stm32l496_discovery/inc/lwmem_opts.h
@@ -29,7 +29,6 @@
  * This file is part of LwMEM - Lightweight dynamic memory manager library.
  *
  * Author:          Tilen MAJERLE <tilen@majerle.eu>
- * Version:         v1.6.0
  */
 #ifndef LWMEM_HDR_OPTS_H
 #define LWMEM_HDR_OPTS_H
diff --git a/examples/stm32/lwmem_stm32l496_discovery/inc/main.h b/examples/stm32/lwmem_stm32l496_discovery/inc/main.h
index 2ef3d4a..4bff3ec 100644
--- a/examples/stm32/lwmem_stm32l496_discovery/inc/main.h
+++ b/examples/stm32/lwmem_stm32l496_discovery/inc/main.h
@@ -27,7 +27,6 @@
  * OTHER DEALINGS IN THE SOFTWARE.
  *
  * Author:          Tilen MAJERLE <tilen@majerle.eu>
- * Version:         v1.6.0
  */
 #ifndef __MAIN_H
 #define __MAIN_H
diff --git a/examples/stm32/lwmem_stm32l496_discovery/src/main.c b/examples/stm32/lwmem_stm32l496_discovery/src/main.c
index b1af32f..0c47d50 100644
--- a/examples/stm32/lwmem_stm32l496_discovery/src/main.c
+++ b/examples/stm32/lwmem_stm32l496_discovery/src/main.c
@@ -27,7 +27,6 @@
  * OTHER DEALINGS IN THE SOFTWARE.
  *
  * Author:          Tilen MAJERLE <tilen@majerle.eu>
- * Version:         v1.6.0
  */
 #include "main.h"
 #include "lwmem/lwmem.h"
@@ -48,6 +47,7 @@ static lwmem_region_t
 regions[] = {
     { region1_data, sizeof(region1_data) },
     /* Add more regions if needed */
+    { NULL, 0 }
 };
 
 /**
@@ -65,7 +65,7 @@ main(void) {
 
     /* Initialize LwMEM */
     printf("Initializing LwMEM...\r\n");
-    if (!lwmem_assignmem(regions, sizeof(regions) / sizeof(regions[0]))) {
+    if (!lwmem_assignmem(regions)) {
         printf("Cannot initialize LwMEM. Make sure your regions are not overlapping each other and are in ascending memory order\r\n");
         while (1) {}
     } else {
diff --git a/examples/win32/lwmem/lwmem_opts.h b/examples/win32/lwmem/lwmem_opts.h
index 2f031ac..1f94312 100644
--- a/examples/win32/lwmem/lwmem_opts.h
+++ b/examples/win32/lwmem/lwmem_opts.h
@@ -29,7 +29,6 @@
  * This file is part of LwMEM - Lightweight dynamic memory manager library.
  *
  * Author:          Tilen MAJERLE <tilen@majerle.eu>
- * Version:         v1.6.0
  */
 #ifndef LWMEM_HDR_OPTS_H
 #define LWMEM_HDR_OPTS_H
diff --git a/examples/win32/lwmem/main.c b/examples/win32/lwmem/main.c
index e0b301b..e1db8f1 100644
--- a/examples/win32/lwmem/main.c
+++ b/examples/win32/lwmem/main.c
@@ -9,9 +9,9 @@
 
 /* Define single region */
 uint8_t region_data[1024];
-lwmem_region_t region = {
-    .start_addr = region_data,
-    .size = sizeof(region_data)
+lwmem_region_t regions[] = {
+    { .start_addr = region_data, .size = sizeof(region_data) },
+    { .start_addr = NULL, .size = 0 }
 };
 
 int
@@ -19,7 +19,7 @@ main(void) {
     void* ptr, *ptr2;
 
     /* Initialize default LwMEM instance with single region */
-    if (!lwmem_assignmem(&region, 1)) {
+    if (!lwmem_assignmem(regions)) {
         printf("Could not initialize LwMEM!");
         return -1;
     }
diff --git a/examples/win32/lwmem_multi_ins_multi_region/lwmem_opts.h b/examples/win32/lwmem_multi_ins_multi_region/lwmem_opts.h
index 2f031ac..1f94312 100644
--- a/examples/win32/lwmem_multi_ins_multi_region/lwmem_opts.h
+++ b/examples/win32/lwmem_multi_ins_multi_region/lwmem_opts.h
@@ -29,7 +29,6 @@
  * This file is part of LwMEM - Lightweight dynamic memory manager library.
  *
  * Author:          Tilen MAJERLE <tilen@majerle.eu>
- * Version:         v1.6.0
  */
 #ifndef LWMEM_HDR_OPTS_H
 #define LWMEM_HDR_OPTS_H
diff --git a/examples/win32/lwmem_multi_ins_multi_region/main.c b/examples/win32/lwmem_multi_ins_multi_region/main.c
index 47e3b59..bc14e9a 100644
--- a/examples/win32/lwmem_multi_ins_multi_region/main.c
+++ b/examples/win32/lwmem_multi_ins_multi_region/main.c
@@ -7,13 +7,15 @@
 
 #include "lwmem/lwmem.h"
 #include <stdio.h>
+#include <string.h>
 
 /* Define multiple regions for default instance */
 uint8_t lw0_region1_data[1024];
 uint8_t lw0_region2_data[256];
 lwmem_region_t lw0_regions[] = {
     { .start_addr = lw0_region1_data, .size = sizeof(lw0_region1_data) },
-    { .start_addr = lw0_region2_data, .size = sizeof(lw0_region2_data) }
+    { .start_addr = lw0_region2_data, .size = sizeof(lw0_region2_data) },
+    { .start_addr = NULL, .size = 0 },
 };
 
 /* Define second LwMEM instance and multiple regions for new instance */
@@ -21,8 +23,9 @@ lwmem_t lw1;
 uint8_t lw1_region1_data[1024];
 uint8_t lw1_region2_data[512];
 lwmem_region_t lw1_regions[] = {
-    {.start_addr = lw1_region1_data, .size = sizeof(lw1_region1_data) },
-    {.start_addr = lw1_region2_data, .size = sizeof(lw1_region2_data) }
+    { .start_addr = lw1_region1_data, .size = sizeof(lw1_region1_data) },
+    { .start_addr = lw1_region2_data, .size = sizeof(lw1_region2_data) },
+    { .start_addr = NULL, .size = 0 },
 };
 
 int
@@ -45,14 +48,14 @@ main(void) {
     }
 
     /* Initialize default LwMEM instance with single region */
-    if (!lwmem_assignmem(lw0_regions, LWMEM_ARRAYSIZE(lw0_regions))) {
+    if (!lwmem_assignmem(lw0_regions)) {
         printf("Could not initialize default LwMEM instance!");
         return -1;
     }
     printf("Default LwMEM instance initialized and ready to use!\r\n");
 
     /* Initialize custom LwMEM instance with its custom regions */
-    if (!lwmem_assignmem_ex(&lw1, lw1_regions, LWMEM_ARRAYSIZE(lw1_regions))) {
+    if (!lwmem_assignmem_ex(&lw1, lw1_regions)) {
         printf("Could not initialize custom LwMEM instance!");
         return -1;
     }
diff --git a/examples/win32/lwmem_multi_region/lwmem_opts.h b/examples/win32/lwmem_multi_region/lwmem_opts.h
index 2f031ac..1f94312 100644
--- a/examples/win32/lwmem_multi_region/lwmem_opts.h
+++ b/examples/win32/lwmem_multi_region/lwmem_opts.h
@@ -29,7 +29,6 @@
  * This file is part of LwMEM - Lightweight dynamic memory manager library.
  *
  * Author:          Tilen MAJERLE <tilen@majerle.eu>
- * Version:         v1.6.0
  */
 #ifndef LWMEM_HDR_OPTS_H
 #define LWMEM_HDR_OPTS_H
diff --git a/examples/win32/lwmem_multi_region/main.c b/examples/win32/lwmem_multi_region/main.c
index dc9d7e8..50dca58 100644
--- a/examples/win32/lwmem_multi_region/main.c
+++ b/examples/win32/lwmem_multi_region/main.c
@@ -6,13 +6,15 @@
 
 #include "lwmem/lwmem.h"
 #include <stdio.h>
+#include <string.h>
 
 /* Define multiple regions */
 uint8_t region1_data[1024];
 uint8_t region2_data[256];
 lwmem_region_t regions[] = {
     { .start_addr = region1_data, .size = sizeof(region1_data) },
-    { .start_addr = region2_data, .size = sizeof(region2_data) }
+    { .start_addr = region2_data, .size = sizeof(region2_data) },
+    { .start_addr = NULL, .size = 0 },
 };
 
 int
@@ -28,7 +30,7 @@ main(void) {
     }
 
     /* Initialize default LwMEM instance with single region */
-    if (!lwmem_assignmem(regions, LWMEM_ARRAYSIZE(regions))) {
+    if (!lwmem_assignmem(regions)) {
         printf("Could not initialize LwMEM!");
         return -1;
     }
diff --git a/examples/win32/lwmem_os/lwmem_opts.h b/examples/win32/lwmem_os/lwmem_opts.h
index f6429c7..8536f88 100644
--- a/examples/win32/lwmem_os/lwmem_opts.h
+++ b/examples/win32/lwmem_os/lwmem_opts.h
@@ -29,7 +29,6 @@
  * This file is part of LwMEM - Lightweight dynamic memory manager library.
  *
  * Author:          Tilen MAJERLE <tilen@majerle.eu>
- * Version:         v1.6.0
  */
 #ifndef LWMEM_HDR_OPTS_H
 #define LWMEM_HDR_OPTS_H
diff --git a/examples/win32/lwmem_os/main.c b/examples/win32/lwmem_os/main.c
index 344e49d..a1a4733 100644
--- a/examples/win32/lwmem_os/main.c
+++ b/examples/win32/lwmem_os/main.c
@@ -10,9 +10,9 @@
 
 /* Define single region */
 uint8_t region_data[1024];
-lwmem_region_t region = {
-    .start_addr = region_data,
-    .size = sizeof(region_data)
+lwmem_region_t regions[] = {
+    { .start_addr = region_data, .size = sizeof(region_data) },
+    { .start_addr = NULL, .size = 0 },
 };
 
 /* Thread declaration */
@@ -21,7 +21,7 @@ static int thread_func(void* arg);
 int
 main(void) {
     /* Initialize default LwMEM instance with single region */
-    if (!lwmem_assignmem(&region, 1)) {
+    if (!lwmem_assignmem(regions)) {
         printf("Could not initialize LwMEM!");
         return -1;
     }
diff --git a/library.json b/library.json
index c8f9c15..972dba8 100644
--- a/library.json
+++ b/library.json
@@ -1,6 +1,6 @@
 {
 	"name": "LwMEM",
-	"version": "1.6.0",
+	"version": "2.0.0",
 	"description": "Lightweight dynamic memory manager optimized for embedded systems",
 	"keywords": "lwmem, memory, dynamic, heap, malloc, calloc, realloc, free, lightweight, manager, embedded, stm32, win32",
 	"repository": {
@@ -23,10 +23,12 @@
 	"platforms": "*",
 	"export": {
 		"exclude": [
+			".github",
+			"dev"
 			"docs",
 			"**/.vs",
 			"**/Debug",
-			"third_party/embedded-libs/st_hal/CMSIS/Lib/ARM"
+			"build",
 		]
 	}
 }
\ No newline at end of file
diff --git a/lwmem/src/include/lwmem/lwmem.h b/lwmem/src/include/lwmem/lwmem.h
index 03835d6..90c579a 100644
--- a/lwmem/src/include/lwmem/lwmem.h
+++ b/lwmem/src/include/lwmem/lwmem.h
@@ -29,7 +29,7 @@
  * This file is part of LwMEM - Lightweight dynamic memory manager library.
  *
  * Author:          Tilen MAJERLE <tilen@majerle.eu>
- * Version:         v1.6.0
+ * Version:         v2.0.0
  */
 #ifndef LWMEM_HDR_H
 #define LWMEM_HDR_H
@@ -102,7 +102,7 @@ typedef struct {
     size_t size;                                /*!< Size of region in units of bytes */
 } lwmem_region_t;
 
-size_t      lwmem_assignmem_ex(lwmem_t* const lw, const lwmem_region_t* regions, size_t len);
+size_t      lwmem_assignmem_ex(lwmem_t* const lw, const lwmem_region_t* regions);
 void*       lwmem_malloc_ex(lwmem_t* const lw, const lwmem_region_t* region, const size_t size);
 void*       lwmem_calloc_ex(lwmem_t* const lw, const lwmem_region_t* region, const size_t nitems, const size_t size);
 void*       lwmem_realloc_ex(lwmem_t* const lw, const lwmem_region_t* region, void* const ptr, const size_t size);
@@ -114,15 +114,21 @@ size_t      lwmem_get_size_ex(lwmem_t* const lw, void* ptr);
 /**
  * \note            This is a wrapper for \ref lwmem_assignmem_ex function.
  *                      It operates in default LwMEM instance and uses first available region for memory operations
- * \param[in]       regions: Array of regions with address and its size.
+ * \param[in]       regions: Pointer to array of regions with address and respective size.
  *                      Regions must be in increasing order (start address) and must not overlap in-between.
- *                      When `len` param is set to `0`, regions array must contain last entry with `NULL` address and `0` length
- * \param[in]       len: Number of regions in array.
- *                      Can be set to `0` to describe number of regions with `regions` parameter.
- *                      Array must have last entry with `0` length and `NULL` address, indicating end of array (similar to end of string)
+ *                      Last region entry must have address `NULL` and size set to `0`
+ * \code{.c}
+//Example definition
+lwmem_region_t regions[] = {
+    { (void *)0x10000000, 0x1000 }, //Region starts at address 0x10000000 and is 0x1000 bytes long
+    { (void *)0x20000000, 0x2000 }, //Region starts at address 0x20000000 and is 0x2000 bytes long
+    { (void *)0x30000000, 0x3000 }, //Region starts at address 0x30000000 and is 0x3000 bytes long
+    { NULL, 0 }                     //Array termination indicator
+}
+\endcode
  * \return          `0` on failure, number of final regions used for memory manager on success
  */
-#define     lwmem_assignmem(regions, len)           lwmem_assignmem_ex(NULL, (regions), (len))
+#define     lwmem_assignmem(regions)                lwmem_assignmem_ex(NULL, (regions))
 
 /**
  * \note            This is a wrapper for \ref lwmem_malloc_ex function.
diff --git a/lwmem/src/include/lwmem/lwmem_opt.h b/lwmem/src/include/lwmem/lwmem_opt.h
index fdc8ee5..8050d88 100644
--- a/lwmem/src/include/lwmem/lwmem_opt.h
+++ b/lwmem/src/include/lwmem/lwmem_opt.h
@@ -29,7 +29,7 @@
  * This file is part of LwMEM - Lightweight dynamic memory manager library.
  *
  * Author:          Tilen MAJERLE <tilen@majerle.eu>
- * Version:         v1.6.0
+ * Version:         v2.0.0
  */
 #ifndef LWMEM_HDR_OPT_H
 #define LWMEM_HDR_OPT_H
diff --git a/lwmem/src/include/lwmem/lwmem_opts_template.h b/lwmem/src/include/lwmem/lwmem_opts_template.h
index adb08cb..ccac00c 100644
--- a/lwmem/src/include/lwmem/lwmem_opts_template.h
+++ b/lwmem/src/include/lwmem/lwmem_opts_template.h
@@ -29,7 +29,7 @@
  * This file is part of LwMEM - Lightweight dynamic memory manager library.
  *
  * Author:          Tilen MAJERLE <tilen@majerle.eu>
- * Version:         v1.6.0
+ * Version:         v2.0.0
  */
 #ifndef LWMEM_HDR_OPTS_H
 #define LWMEM_HDR_OPTS_H
diff --git a/lwmem/src/include/system/lwmem_sys.h b/lwmem/src/include/system/lwmem_sys.h
index 8d295ab..9afb1e0 100644
--- a/lwmem/src/include/system/lwmem_sys.h
+++ b/lwmem/src/include/system/lwmem_sys.h
@@ -29,7 +29,7 @@
  * This file is part of LwMEM - Lightweight dynamic memory manager library.
  *
  * Author:          Tilen MAJERLE <tilen@majerle.eu>
- * Version:         v1.6.0
+ * Version:         v2.0.0
  */
 #ifndef LWMEM_HDR_SYS_H
 #define LWMEM_HDR_SYS_H
diff --git a/lwmem/src/lwmem/lwmem.c b/lwmem/src/lwmem/lwmem.c
index 2da3712..67f369e 100644
--- a/lwmem/src/lwmem/lwmem.c
+++ b/lwmem/src/lwmem/lwmem.c
@@ -29,7 +29,7 @@
  * This file is part of LwMEM - Lightweight dynamic memory manager library.
  *
  * Author:          Tilen MAJERLE <tilen@majerle.eu>
- * Version:         v1.6.0
+ * Version:         v2.0.0
  */
 #include <limits.h>
 #include <string.h>
@@ -660,60 +660,49 @@ prv_realloc(lwmem_t* const lw, const lwmem_region_t* region, void* const ptr, co
 /**
  * \brief           Initializes and assigns user regions for memory used by allocator algorithm
  * \param[in]       lw: LwMEM instance. Set to `NULL` to use default instance
- * \param[in]       regions: Array of regions with address and its size.
+ * \param[in]       regions: Pointer to array of regions with address and respective size.
  *                      Regions must be in increasing order (start address) and must not overlap in-between.
- *                      When `len` param is set to `0`, regions array must contain last entry with `NULL` address and `0` length
- * \param[in]       len: Number of regions in array.
- *                      Can be set to `0` to describe number of regions with `regions` parameter.
- *                      Array must have last entry with `0` length and `NULL` address, indicating end of array (similar to end of string)
+ *                      Last region entry must have address `NULL` and size set to `0`
+ * \code{.c}
+//Example definition
+lwmem_region_t regions[] = {
+    { (void *)0x10000000, 0x1000 }, //Region starts at address 0x10000000 and is 0x1000 bytes long
+    { (void *)0x20000000, 0x2000 }, //Region starts at address 0x20000000 and is 0x2000 bytes long
+    { (void *)0x30000000, 0x3000 }, //Region starts at address 0x30000000 and is 0x3000 bytes long
+    { NULL, 0 }                     //Array termination indicator
+}
+\endcode
  * \return          `0` on failure, number of final regions used for memory manager on success
  * \note            This function is not thread safe when used with operating system.
  *                      It must be called only once to setup memory regions
  */
 size_t
-lwmem_assignmem_ex(lwmem_t* const lw, const lwmem_region_t* regions, size_t len) {
+lwmem_assignmem_ex(lwmem_t* const lw, const lwmem_region_t* regions) {
     uint8_t* mem_start_addr;
-    size_t mem_size;
+    size_t mem_size, len = 0;
     lwmem_block_t* first_block, *prev_end_block;
 
-    /* Check first entries */
-    if (LWMEM_GET_LW(lw)->end_block != NULL     /* Init function may only be called once per lwmem instance */
+    /* Check first things first */
+    if (regions == NULL
+        || LWMEM_GET_LW(lw)->end_block != NULL  /* Init function may only be called once per lwmem instance */
         || (((size_t)LWMEM_CFG_ALIGN_NUM) & (((size_t)LWMEM_CFG_ALIGN_NUM) - 1)) > 0) { /* Must be power of 2 */
         return 0;    
     }
 
-    /*
-     * When len == 0, number of regions is defined by pointer to regions.
-     *
-     * Last entry, indicating end of region, must have address and length to `NULL` and `0` respectively
-     */
-    if (regions != NULL && len == 0) {
-        /* Go through array of regions */
-        for (const lwmem_region_t* r = regions; r->size > 0 && r->start_addr != NULL; ++len, ++r) {}
-    }
-
-    /* Process further checks of valid inputs */
-    if (regions == NULL || len == 0
-#if LWMEM_CFG_OS
-        || lwmem_sys_mutex_isvalid(&(LWMEM_GET_LW(lw)->mutex))  /* Check if mutex valid already */
-#endif /* LWMEM_CFG_OS */
-       ) {                                      /* Check inputs */
-        return 0;
-    }
-
-#if LWMEM_CFG_OS
-    if (!lwmem_sys_mutex_create(&(LWMEM_GET_LW(lw)->mutex))) {
-        return 0;
-    }
-#endif /* LWMEM_CFG_OS */
-
-    /* Ensure regions are growing linearly and do not overlap in between */
+    /* Check values entered by application */
     mem_start_addr = (void*)0;
     mem_size = 0;
-    for (size_t i = 0; i < len; ++i) {
-        /* Make sure for valid entry */
+    for (size_t i = 0;; ++i) {
+        /* 
+         * Check for valid entry or end of array descriptor
+         *
+         * Invalid entry is considered as "end-of-region" indicator
+         */
         if (regions[i].size == 0 && regions[i].start_addr == NULL) {
             len = i;
+            if (len == 0) {
+                return 0;
+            }
             break;
         }
 
@@ -722,11 +711,21 @@ lwmem_assignmem_ex(lwmem_t* const lw, const lwmem_region_t* regions, size_t len)
             return 0;
         }
 
-        /* Save new values for next try */
+        /* Save new values for next round */
         mem_start_addr = regions[i].start_addr;
         mem_size = regions[i].size;
     }
 
+    /* Process further checks of valid inputs */
+    if (regions == NULL || len == 0
+#if LWMEM_CFG_OS
+        || lwmem_sys_mutex_isvalid(&(LWMEM_GET_LW(lw)->mutex))  /* Check if mutex valid already = must not be */
+        || !lwmem_sys_mutex_create(&(LWMEM_GET_LW(lw)->mutex))  /* Final step = try to create mutex for new instance */
+#endif /* LWMEM_CFG_OS */
+       ) {
+        return 0;
+    }
+
     for (size_t i = 0; i < len; ++i, ++regions) {
         /* Get region start address and size */
         if (!prv_get_region_addr_size(regions, &mem_start_addr, &mem_size)) {
diff --git a/lwmem/src/system/lwmem_sys_cmsis_os.c b/lwmem/src/system/lwmem_sys_cmsis_os.c
index 8d7997c..17bf646 100644
--- a/lwmem/src/system/lwmem_sys_cmsis_os.c
+++ b/lwmem/src/system/lwmem_sys_cmsis_os.c
@@ -29,7 +29,7 @@
  * This file is part of LwMEM - Lightweight dynamic memory manager library.
  *
  * Author:          Tilen MAJERLE <tilen@majerle.eu>
- * Version:         v1.6.0
+ * Version:         v2.0.0
  */
 #include "system/lwmem_sys.h"
 
diff --git a/lwmem/src/system/lwmem_sys_win32.c b/lwmem/src/system/lwmem_sys_win32.c
index f178131..5fdb647 100644
--- a/lwmem/src/system/lwmem_sys_win32.c
+++ b/lwmem/src/system/lwmem_sys_win32.c
@@ -29,7 +29,7 @@
  * This file is part of LwMEM - Lightweight dynamic memory manager library.
  *
  * Author:          Tilen MAJERLE <tilen@majerle.eu>
- * Version:         v1.6.0
+ * Version:         v2.0.0
  */
 #include "system/lwmem_sys.h"
 
diff --git a/tests/lwmem_test.c b/tests/lwmem_test.c
index 62fe434..e3b33d6 100644
--- a/tests/lwmem_test.c
+++ b/tests/lwmem_test.c
@@ -30,6 +30,7 @@ lw_regions[] = {
     { lw_mem3, sizeof(lw_mem3) },
     { lw_mem2, sizeof(lw_mem2) },
     { lw_mem1, sizeof(lw_mem1) },
+    { NULL, 0 }
 };
 
 /********************************************/
@@ -47,6 +48,7 @@ lw_c_regions[] = {
     { lw_c_mem3, sizeof(lw_c_mem3) },
     { lw_c_mem2, sizeof(lw_c_mem2) },
     { lw_c_mem1, sizeof(lw_c_mem1) },
+    { NULL, 0 }
 };
 /********************************************/
 
@@ -57,11 +59,11 @@ lwmem_test_run(void) {
 
     /* Initialize default lwmem instance */
     /* Use one of 2 possible function calls: */
-    lwmem_assignmem(lw_regions, sizeof(lw_regions) / sizeof(lw_regions[0]));
-    //lwmem_assignmem_ex(NULL, lw_regions, sizeof(lw_regions) / sizeof(lw_regions[0]));
+    lwmem_assignmem(lw_regions);
+    //lwmem_assignmem_ex(NULL, lw_regions);
 
     /* Initialize another, custom instance */
-    lwmem_assignmem_ex(&lw_c, lw_c_regions, sizeof(lw_c_regions) / sizeof(lw_c_regions[0]));
+    lwmem_assignmem_ex(&lw_c, lw_c_regions);
 
     /* Regions initialized... */
 
@@ -148,7 +150,7 @@ lwmem_test_memory_structure(void) {
      * Assign memory for LwMEM. Set len parameter to 0 to calculate
      * Number of regions with regions pointer, with last entry being set to NULL and 0
      */
-    used_regions = lwmem_assignmem(regions_used, 0);
+    used_regions = lwmem_assignmem(regions_used);
     printf("Manager is ready with %d regions!\r\n", (int)used_regions);
     lwmem_debug_print(1, 1);