/ Drivers / CMSIS / Core / Include / core_cm0.h
core_cm0.h
  1  /**************************************************************************//**
  2   * @file     core_cm0.h
  3   * @brief    CMSIS Cortex-M0 Core Peripheral Access Layer Header File
  4   * @version  V5.0.8
  5   * @date     21. August 2019
  6   ******************************************************************************/
  7  /*
  8   * Copyright (c) 2009-2019 Arm Limited. All rights reserved.
  9   *
 10   * SPDX-License-Identifier: Apache-2.0
 11   *
 12   * Licensed under the Apache License, Version 2.0 (the License); you may
 13   * not use this file except in compliance with the License.
 14   * You may obtain a copy of the License at
 15   *
 16   * www.apache.org/licenses/LICENSE-2.0
 17   *
 18   * Unless required by applicable law or agreed to in writing, software
 19   * distributed under the License is distributed on an AS IS BASIS, WITHOUT
 20   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 21   * See the License for the specific language governing permissions and
 22   * limitations under the License.
 23   */
 24  
 25  #if   defined ( __ICCARM__ )
 26    #pragma system_include         /* treat file as system include file for MISRA check */
 27  #elif defined (__clang__)
 28    #pragma clang system_header   /* treat file as system include file */
 29  #endif
 30  
 31  #ifndef __CORE_CM0_H_GENERIC
 32  #define __CORE_CM0_H_GENERIC
 33  
 34  #include <stdint.h>
 35  
 36  #ifdef __cplusplus
 37   extern "C" {
 38  #endif
 39  
 40  /**
 41    \page CMSIS_MISRA_Exceptions  MISRA-C:2004 Compliance Exceptions
 42    CMSIS violates the following MISRA-C:2004 rules:
 43  
 44     \li Required Rule 8.5, object/function definition in header file.<br>
 45       Function definitions in header files are used to allow 'inlining'.
 46  
 47     \li Required Rule 18.4, declaration of union type or object of union type: '{...}'.<br>
 48       Unions are used for effective representation of core registers.
 49  
 50     \li Advisory Rule 19.7, Function-like macro defined.<br>
 51       Function-like macros are used to allow more efficient code.
 52   */
 53  
 54  
 55  /*******************************************************************************
 56   *                 CMSIS definitions
 57   ******************************************************************************/
 58  /**
 59    \ingroup Cortex_M0
 60    @{
 61   */
 62  
 63  #include "cmsis_version.h"
 64   
 65  /*  CMSIS CM0 definitions */
 66  #define __CM0_CMSIS_VERSION_MAIN  (__CM_CMSIS_VERSION_MAIN)              /*!< \deprecated [31:16] CMSIS HAL main version */
 67  #define __CM0_CMSIS_VERSION_SUB   (__CM_CMSIS_VERSION_SUB)               /*!< \deprecated [15:0]  CMSIS HAL sub version */
 68  #define __CM0_CMSIS_VERSION       ((__CM0_CMSIS_VERSION_MAIN << 16U) | \
 69                                      __CM0_CMSIS_VERSION_SUB           )  /*!< \deprecated CMSIS HAL version number */
 70  
 71  #define __CORTEX_M                (0U)                                   /*!< Cortex-M Core */
 72  
 73  /** __FPU_USED indicates whether an FPU is used or not.
 74      This core does not support an FPU at all
 75  */
 76  #define __FPU_USED       0U
 77  
 78  #if defined ( __CC_ARM )
 79    #if defined __TARGET_FPU_VFP
 80      #error "Compiler generates FPU instructions for a device without an FPU (check __FPU_PRESENT)"
 81    #endif
 82  
 83  #elif defined (__ARMCC_VERSION) && (__ARMCC_VERSION >= 6010050)
 84    #if defined __ARM_FP
 85      #error "Compiler generates FPU instructions for a device without an FPU (check __FPU_PRESENT)"
 86    #endif
 87  
 88  #elif defined ( __GNUC__ )
 89    #if defined (__VFP_FP__) && !defined(__SOFTFP__)
 90      #error "Compiler generates FPU instructions for a device without an FPU (check __FPU_PRESENT)"
 91    #endif
 92  
 93  #elif defined ( __ICCARM__ )
 94    #if defined __ARMVFP__
 95      #error "Compiler generates FPU instructions for a device without an FPU (check __FPU_PRESENT)"
 96    #endif
 97  
 98  #elif defined ( __TI_ARM__ )
 99    #if defined __TI_VFP_SUPPORT__
100      #error "Compiler generates FPU instructions for a device without an FPU (check __FPU_PRESENT)"
101    #endif
102  
103  #elif defined ( __TASKING__ )
104    #if defined __FPU_VFP__
105      #error "Compiler generates FPU instructions for a device without an FPU (check __FPU_PRESENT)"
106    #endif
107  
108  #elif defined ( __CSMC__ )
109    #if ( __CSMC__ & 0x400U)
110      #error "Compiler generates FPU instructions for a device without an FPU (check __FPU_PRESENT)"
111    #endif
112  
113  #endif
114  
115  #include "cmsis_compiler.h"               /* CMSIS compiler specific defines */
116  
117  
118  #ifdef __cplusplus
119  }
120  #endif
121  
122  #endif /* __CORE_CM0_H_GENERIC */
123  
124  #ifndef __CMSIS_GENERIC
125  
126  #ifndef __CORE_CM0_H_DEPENDANT
127  #define __CORE_CM0_H_DEPENDANT
128  
129  #ifdef __cplusplus
130   extern "C" {
131  #endif
132  
133  /* check device defines and use defaults */
134  #if defined __CHECK_DEVICE_DEFINES
135    #ifndef __CM0_REV
136      #define __CM0_REV               0x0000U
137      #warning "__CM0_REV not defined in device header file; using default!"
138    #endif
139  
140    #ifndef __NVIC_PRIO_BITS
141      #define __NVIC_PRIO_BITS          2U
142      #warning "__NVIC_PRIO_BITS not defined in device header file; using default!"
143    #endif
144  
145    #ifndef __Vendor_SysTickConfig
146      #define __Vendor_SysTickConfig    0U
147      #warning "__Vendor_SysTickConfig not defined in device header file; using default!"
148    #endif
149  #endif
150  
151  /* IO definitions (access restrictions to peripheral registers) */
152  /**
153      \defgroup CMSIS_glob_defs CMSIS Global Defines
154  
155      <strong>IO Type Qualifiers</strong> are used
156      \li to specify the access to peripheral variables.
157      \li for automatic generation of peripheral register debug information.
158  */
159  #ifdef __cplusplus
160    #define   __I     volatile             /*!< Defines 'read only' permissions */
161  #else
162    #define   __I     volatile const       /*!< Defines 'read only' permissions */
163  #endif
164  #define     __O     volatile             /*!< Defines 'write only' permissions */
165  #define     __IO    volatile             /*!< Defines 'read / write' permissions */
166  
167  /* following defines should be used for structure members */
168  #define     __IM     volatile const      /*! Defines 'read only' structure member permissions */
169  #define     __OM     volatile            /*! Defines 'write only' structure member permissions */
170  #define     __IOM    volatile            /*! Defines 'read / write' structure member permissions */
171  
172  /*@} end of group Cortex_M0 */
173  
174  
175  
176  /*******************************************************************************
177   *                 Register Abstraction
178    Core Register contain:
179    - Core Register
180    - Core NVIC Register
181    - Core SCB Register
182    - Core SysTick Register
183   ******************************************************************************/
184  /**
185    \defgroup CMSIS_core_register Defines and Type Definitions
186    \brief Type definitions and defines for Cortex-M processor based devices.
187  */
188  
189  /**
190    \ingroup    CMSIS_core_register
191    \defgroup   CMSIS_CORE  Status and Control Registers
192    \brief      Core Register type definitions.
193    @{
194   */
195  
196  /**
197    \brief  Union type to access the Application Program Status Register (APSR).
198   */
199  typedef union
200  {
201    struct
202    {
203      uint32_t _reserved0:28;              /*!< bit:  0..27  Reserved */
204      uint32_t V:1;                        /*!< bit:     28  Overflow condition code flag */
205      uint32_t C:1;                        /*!< bit:     29  Carry condition code flag */
206      uint32_t Z:1;                        /*!< bit:     30  Zero condition code flag */
207      uint32_t N:1;                        /*!< bit:     31  Negative condition code flag */
208    } b;                                   /*!< Structure used for bit  access */
209    uint32_t w;                            /*!< Type      used for word access */
210  } APSR_Type;
211  
212  /* APSR Register Definitions */
213  #define APSR_N_Pos                         31U                                            /*!< APSR: N Position */
214  #define APSR_N_Msk                         (1UL << APSR_N_Pos)                            /*!< APSR: N Mask */
215  
216  #define APSR_Z_Pos                         30U                                            /*!< APSR: Z Position */
217  #define APSR_Z_Msk                         (1UL << APSR_Z_Pos)                            /*!< APSR: Z Mask */
218  
219  #define APSR_C_Pos                         29U                                            /*!< APSR: C Position */
220  #define APSR_C_Msk                         (1UL << APSR_C_Pos)                            /*!< APSR: C Mask */
221  
222  #define APSR_V_Pos                         28U                                            /*!< APSR: V Position */
223  #define APSR_V_Msk                         (1UL << APSR_V_Pos)                            /*!< APSR: V Mask */
224  
225  
226  /**
227    \brief  Union type to access the Interrupt Program Status Register (IPSR).
228   */
229  typedef union
230  {
231    struct
232    {
233      uint32_t ISR:9;                      /*!< bit:  0.. 8  Exception number */
234      uint32_t _reserved0:23;              /*!< bit:  9..31  Reserved */
235    } b;                                   /*!< Structure used for bit  access */
236    uint32_t w;                            /*!< Type      used for word access */
237  } IPSR_Type;
238  
239  /* IPSR Register Definitions */
240  #define IPSR_ISR_Pos                        0U                                            /*!< IPSR: ISR Position */
241  #define IPSR_ISR_Msk                       (0x1FFUL /*<< IPSR_ISR_Pos*/)                  /*!< IPSR: ISR Mask */
242  
243  
244  /**
245    \brief  Union type to access the Special-Purpose Program Status Registers (xPSR).
246   */
247  typedef union
248  {
249    struct
250    {
251      uint32_t ISR:9;                      /*!< bit:  0.. 8  Exception number */
252      uint32_t _reserved0:15;              /*!< bit:  9..23  Reserved */
253      uint32_t T:1;                        /*!< bit:     24  Thumb bit        (read 0) */
254      uint32_t _reserved1:3;               /*!< bit: 25..27  Reserved */
255      uint32_t V:1;                        /*!< bit:     28  Overflow condition code flag */
256      uint32_t C:1;                        /*!< bit:     29  Carry condition code flag */
257      uint32_t Z:1;                        /*!< bit:     30  Zero condition code flag */
258      uint32_t N:1;                        /*!< bit:     31  Negative condition code flag */
259    } b;                                   /*!< Structure used for bit  access */
260    uint32_t w;                            /*!< Type      used for word access */
261  } xPSR_Type;
262  
263  /* xPSR Register Definitions */
264  #define xPSR_N_Pos                         31U                                            /*!< xPSR: N Position */
265  #define xPSR_N_Msk                         (1UL << xPSR_N_Pos)                            /*!< xPSR: N Mask */
266  
267  #define xPSR_Z_Pos                         30U                                            /*!< xPSR: Z Position */
268  #define xPSR_Z_Msk                         (1UL << xPSR_Z_Pos)                            /*!< xPSR: Z Mask */
269  
270  #define xPSR_C_Pos                         29U                                            /*!< xPSR: C Position */
271  #define xPSR_C_Msk                         (1UL << xPSR_C_Pos)                            /*!< xPSR: C Mask */
272  
273  #define xPSR_V_Pos                         28U                                            /*!< xPSR: V Position */
274  #define xPSR_V_Msk                         (1UL << xPSR_V_Pos)                            /*!< xPSR: V Mask */
275  
276  #define xPSR_T_Pos                         24U                                            /*!< xPSR: T Position */
277  #define xPSR_T_Msk                         (1UL << xPSR_T_Pos)                            /*!< xPSR: T Mask */
278  
279  #define xPSR_ISR_Pos                        0U                                            /*!< xPSR: ISR Position */
280  #define xPSR_ISR_Msk                       (0x1FFUL /*<< xPSR_ISR_Pos*/)                  /*!< xPSR: ISR Mask */
281  
282  
283  /**
284    \brief  Union type to access the Control Registers (CONTROL).
285   */
286  typedef union
287  {
288    struct
289    {
290      uint32_t _reserved0:1;               /*!< bit:      0  Reserved */
291      uint32_t SPSEL:1;                    /*!< bit:      1  Stack to be used */
292      uint32_t _reserved1:30;              /*!< bit:  2..31  Reserved */
293    } b;                                   /*!< Structure used for bit  access */
294    uint32_t w;                            /*!< Type      used for word access */
295  } CONTROL_Type;
296  
297  /* CONTROL Register Definitions */
298  #define CONTROL_SPSEL_Pos                   1U                                            /*!< CONTROL: SPSEL Position */
299  #define CONTROL_SPSEL_Msk                  (1UL << CONTROL_SPSEL_Pos)                     /*!< CONTROL: SPSEL Mask */
300  
301  /*@} end of group CMSIS_CORE */
302  
303  
304  /**
305    \ingroup    CMSIS_core_register
306    \defgroup   CMSIS_NVIC  Nested Vectored Interrupt Controller (NVIC)
307    \brief      Type definitions for the NVIC Registers
308    @{
309   */
310  
311  /**
312    \brief  Structure type to access the Nested Vectored Interrupt Controller (NVIC).
313   */
314  typedef struct
315  {
316    __IOM uint32_t ISER[1U];               /*!< Offset: 0x000 (R/W)  Interrupt Set Enable Register */
317          uint32_t RESERVED0[31U];
318    __IOM uint32_t ICER[1U];               /*!< Offset: 0x080 (R/W)  Interrupt Clear Enable Register */
319          uint32_t RESERVED1[31U];
320    __IOM uint32_t ISPR[1U];               /*!< Offset: 0x100 (R/W)  Interrupt Set Pending Register */
321          uint32_t RESERVED2[31U];
322    __IOM uint32_t ICPR[1U];               /*!< Offset: 0x180 (R/W)  Interrupt Clear Pending Register */
323          uint32_t RESERVED3[31U];
324          uint32_t RESERVED4[64U];
325    __IOM uint32_t IP[8U];                 /*!< Offset: 0x300 (R/W)  Interrupt Priority Register */
326  }  NVIC_Type;
327  
328  /*@} end of group CMSIS_NVIC */
329  
330  
331  /**
332    \ingroup  CMSIS_core_register
333    \defgroup CMSIS_SCB     System Control Block (SCB)
334    \brief    Type definitions for the System Control Block Registers
335    @{
336   */
337  
338  /**
339    \brief  Structure type to access the System Control Block (SCB).
340   */
341  typedef struct
342  {
343    __IM  uint32_t CPUID;                  /*!< Offset: 0x000 (R/ )  CPUID Base Register */
344    __IOM uint32_t ICSR;                   /*!< Offset: 0x004 (R/W)  Interrupt Control and State Register */
345          uint32_t RESERVED0;
346    __IOM uint32_t AIRCR;                  /*!< Offset: 0x00C (R/W)  Application Interrupt and Reset Control Register */
347    __IOM uint32_t SCR;                    /*!< Offset: 0x010 (R/W)  System Control Register */
348    __IOM uint32_t CCR;                    /*!< Offset: 0x014 (R/W)  Configuration Control Register */
349          uint32_t RESERVED1;
350    __IOM uint32_t SHP[2U];                /*!< Offset: 0x01C (R/W)  System Handlers Priority Registers. [0] is RESERVED */
351    __IOM uint32_t SHCSR;                  /*!< Offset: 0x024 (R/W)  System Handler Control and State Register */
352  } SCB_Type;
353  
354  /* SCB CPUID Register Definitions */
355  #define SCB_CPUID_IMPLEMENTER_Pos          24U                                            /*!< SCB CPUID: IMPLEMENTER Position */
356  #define SCB_CPUID_IMPLEMENTER_Msk          (0xFFUL << SCB_CPUID_IMPLEMENTER_Pos)          /*!< SCB CPUID: IMPLEMENTER Mask */
357  
358  #define SCB_CPUID_VARIANT_Pos              20U                                            /*!< SCB CPUID: VARIANT Position */
359  #define SCB_CPUID_VARIANT_Msk              (0xFUL << SCB_CPUID_VARIANT_Pos)               /*!< SCB CPUID: VARIANT Mask */
360  
361  #define SCB_CPUID_ARCHITECTURE_Pos         16U                                            /*!< SCB CPUID: ARCHITECTURE Position */
362  #define SCB_CPUID_ARCHITECTURE_Msk         (0xFUL << SCB_CPUID_ARCHITECTURE_Pos)          /*!< SCB CPUID: ARCHITECTURE Mask */
363  
364  #define SCB_CPUID_PARTNO_Pos                4U                                            /*!< SCB CPUID: PARTNO Position */
365  #define SCB_CPUID_PARTNO_Msk               (0xFFFUL << SCB_CPUID_PARTNO_Pos)              /*!< SCB CPUID: PARTNO Mask */
366  
367  #define SCB_CPUID_REVISION_Pos              0U                                            /*!< SCB CPUID: REVISION Position */
368  #define SCB_CPUID_REVISION_Msk             (0xFUL /*<< SCB_CPUID_REVISION_Pos*/)          /*!< SCB CPUID: REVISION Mask */
369  
370  /* SCB Interrupt Control State Register Definitions */
371  #define SCB_ICSR_NMIPENDSET_Pos            31U                                            /*!< SCB ICSR: NMIPENDSET Position */
372  #define SCB_ICSR_NMIPENDSET_Msk            (1UL << SCB_ICSR_NMIPENDSET_Pos)               /*!< SCB ICSR: NMIPENDSET Mask */
373  
374  #define SCB_ICSR_PENDSVSET_Pos             28U                                            /*!< SCB ICSR: PENDSVSET Position */
375  #define SCB_ICSR_PENDSVSET_Msk             (1UL << SCB_ICSR_PENDSVSET_Pos)                /*!< SCB ICSR: PENDSVSET Mask */
376  
377  #define SCB_ICSR_PENDSVCLR_Pos             27U                                            /*!< SCB ICSR: PENDSVCLR Position */
378  #define SCB_ICSR_PENDSVCLR_Msk             (1UL << SCB_ICSR_PENDSVCLR_Pos)                /*!< SCB ICSR: PENDSVCLR Mask */
379  
380  #define SCB_ICSR_PENDSTSET_Pos             26U                                            /*!< SCB ICSR: PENDSTSET Position */
381  #define SCB_ICSR_PENDSTSET_Msk             (1UL << SCB_ICSR_PENDSTSET_Pos)                /*!< SCB ICSR: PENDSTSET Mask */
382  
383  #define SCB_ICSR_PENDSTCLR_Pos             25U                                            /*!< SCB ICSR: PENDSTCLR Position */
384  #define SCB_ICSR_PENDSTCLR_Msk             (1UL << SCB_ICSR_PENDSTCLR_Pos)                /*!< SCB ICSR: PENDSTCLR Mask */
385  
386  #define SCB_ICSR_ISRPREEMPT_Pos            23U                                            /*!< SCB ICSR: ISRPREEMPT Position */
387  #define SCB_ICSR_ISRPREEMPT_Msk            (1UL << SCB_ICSR_ISRPREEMPT_Pos)               /*!< SCB ICSR: ISRPREEMPT Mask */
388  
389  #define SCB_ICSR_ISRPENDING_Pos            22U                                            /*!< SCB ICSR: ISRPENDING Position */
390  #define SCB_ICSR_ISRPENDING_Msk            (1UL << SCB_ICSR_ISRPENDING_Pos)               /*!< SCB ICSR: ISRPENDING Mask */
391  
392  #define SCB_ICSR_VECTPENDING_Pos           12U                                            /*!< SCB ICSR: VECTPENDING Position */
393  #define SCB_ICSR_VECTPENDING_Msk           (0x1FFUL << SCB_ICSR_VECTPENDING_Pos)          /*!< SCB ICSR: VECTPENDING Mask */
394  
395  #define SCB_ICSR_VECTACTIVE_Pos             0U                                            /*!< SCB ICSR: VECTACTIVE Position */
396  #define SCB_ICSR_VECTACTIVE_Msk            (0x1FFUL /*<< SCB_ICSR_VECTACTIVE_Pos*/)       /*!< SCB ICSR: VECTACTIVE Mask */
397  
398  /* SCB Application Interrupt and Reset Control Register Definitions */
399  #define SCB_AIRCR_VECTKEY_Pos              16U                                            /*!< SCB AIRCR: VECTKEY Position */
400  #define SCB_AIRCR_VECTKEY_Msk              (0xFFFFUL << SCB_AIRCR_VECTKEY_Pos)            /*!< SCB AIRCR: VECTKEY Mask */
401  
402  #define SCB_AIRCR_VECTKEYSTAT_Pos          16U                                            /*!< SCB AIRCR: VECTKEYSTAT Position */
403  #define SCB_AIRCR_VECTKEYSTAT_Msk          (0xFFFFUL << SCB_AIRCR_VECTKEYSTAT_Pos)        /*!< SCB AIRCR: VECTKEYSTAT Mask */
404  
405  #define SCB_AIRCR_ENDIANESS_Pos            15U                                            /*!< SCB AIRCR: ENDIANESS Position */
406  #define SCB_AIRCR_ENDIANESS_Msk            (1UL << SCB_AIRCR_ENDIANESS_Pos)               /*!< SCB AIRCR: ENDIANESS Mask */
407  
408  #define SCB_AIRCR_SYSRESETREQ_Pos           2U                                            /*!< SCB AIRCR: SYSRESETREQ Position */
409  #define SCB_AIRCR_SYSRESETREQ_Msk          (1UL << SCB_AIRCR_SYSRESETREQ_Pos)             /*!< SCB AIRCR: SYSRESETREQ Mask */
410  
411  #define SCB_AIRCR_VECTCLRACTIVE_Pos         1U                                            /*!< SCB AIRCR: VECTCLRACTIVE Position */
412  #define SCB_AIRCR_VECTCLRACTIVE_Msk        (1UL << SCB_AIRCR_VECTCLRACTIVE_Pos)           /*!< SCB AIRCR: VECTCLRACTIVE Mask */
413  
414  /* SCB System Control Register Definitions */
415  #define SCB_SCR_SEVONPEND_Pos               4U                                            /*!< SCB SCR: SEVONPEND Position */
416  #define SCB_SCR_SEVONPEND_Msk              (1UL << SCB_SCR_SEVONPEND_Pos)                 /*!< SCB SCR: SEVONPEND Mask */
417  
418  #define SCB_SCR_SLEEPDEEP_Pos               2U                                            /*!< SCB SCR: SLEEPDEEP Position */
419  #define SCB_SCR_SLEEPDEEP_Msk              (1UL << SCB_SCR_SLEEPDEEP_Pos)                 /*!< SCB SCR: SLEEPDEEP Mask */
420  
421  #define SCB_SCR_SLEEPONEXIT_Pos             1U                                            /*!< SCB SCR: SLEEPONEXIT Position */
422  #define SCB_SCR_SLEEPONEXIT_Msk            (1UL << SCB_SCR_SLEEPONEXIT_Pos)               /*!< SCB SCR: SLEEPONEXIT Mask */
423  
424  /* SCB Configuration Control Register Definitions */
425  #define SCB_CCR_STKALIGN_Pos                9U                                            /*!< SCB CCR: STKALIGN Position */
426  #define SCB_CCR_STKALIGN_Msk               (1UL << SCB_CCR_STKALIGN_Pos)                  /*!< SCB CCR: STKALIGN Mask */
427  
428  #define SCB_CCR_UNALIGN_TRP_Pos             3U                                            /*!< SCB CCR: UNALIGN_TRP Position */
429  #define SCB_CCR_UNALIGN_TRP_Msk            (1UL << SCB_CCR_UNALIGN_TRP_Pos)               /*!< SCB CCR: UNALIGN_TRP Mask */
430  
431  /* SCB System Handler Control and State Register Definitions */
432  #define SCB_SHCSR_SVCALLPENDED_Pos         15U                                            /*!< SCB SHCSR: SVCALLPENDED Position */
433  #define SCB_SHCSR_SVCALLPENDED_Msk         (1UL << SCB_SHCSR_SVCALLPENDED_Pos)            /*!< SCB SHCSR: SVCALLPENDED Mask */
434  
435  /*@} end of group CMSIS_SCB */
436  
437  
438  /**
439    \ingroup  CMSIS_core_register
440    \defgroup CMSIS_SysTick     System Tick Timer (SysTick)
441    \brief    Type definitions for the System Timer Registers.
442    @{
443   */
444  
445  /**
446    \brief  Structure type to access the System Timer (SysTick).
447   */
448  typedef struct
449  {
450    __IOM uint32_t CTRL;                   /*!< Offset: 0x000 (R/W)  SysTick Control and Status Register */
451    __IOM uint32_t LOAD;                   /*!< Offset: 0x004 (R/W)  SysTick Reload Value Register */
452    __IOM uint32_t VAL;                    /*!< Offset: 0x008 (R/W)  SysTick Current Value Register */
453    __IM  uint32_t CALIB;                  /*!< Offset: 0x00C (R/ )  SysTick Calibration Register */
454  } SysTick_Type;
455  
456  /* SysTick Control / Status Register Definitions */
457  #define SysTick_CTRL_COUNTFLAG_Pos         16U                                            /*!< SysTick CTRL: COUNTFLAG Position */
458  #define SysTick_CTRL_COUNTFLAG_Msk         (1UL << SysTick_CTRL_COUNTFLAG_Pos)            /*!< SysTick CTRL: COUNTFLAG Mask */
459  
460  #define SysTick_CTRL_CLKSOURCE_Pos          2U                                            /*!< SysTick CTRL: CLKSOURCE Position */
461  #define SysTick_CTRL_CLKSOURCE_Msk         (1UL << SysTick_CTRL_CLKSOURCE_Pos)            /*!< SysTick CTRL: CLKSOURCE Mask */
462  
463  #define SysTick_CTRL_TICKINT_Pos            1U                                            /*!< SysTick CTRL: TICKINT Position */
464  #define SysTick_CTRL_TICKINT_Msk           (1UL << SysTick_CTRL_TICKINT_Pos)              /*!< SysTick CTRL: TICKINT Mask */
465  
466  #define SysTick_CTRL_ENABLE_Pos             0U                                            /*!< SysTick CTRL: ENABLE Position */
467  #define SysTick_CTRL_ENABLE_Msk            (1UL /*<< SysTick_CTRL_ENABLE_Pos*/)           /*!< SysTick CTRL: ENABLE Mask */
468  
469  /* SysTick Reload Register Definitions */
470  #define SysTick_LOAD_RELOAD_Pos             0U                                            /*!< SysTick LOAD: RELOAD Position */
471  #define SysTick_LOAD_RELOAD_Msk            (0xFFFFFFUL /*<< SysTick_LOAD_RELOAD_Pos*/)    /*!< SysTick LOAD: RELOAD Mask */
472  
473  /* SysTick Current Register Definitions */
474  #define SysTick_VAL_CURRENT_Pos             0U                                            /*!< SysTick VAL: CURRENT Position */
475  #define SysTick_VAL_CURRENT_Msk            (0xFFFFFFUL /*<< SysTick_VAL_CURRENT_Pos*/)    /*!< SysTick VAL: CURRENT Mask */
476  
477  /* SysTick Calibration Register Definitions */
478  #define SysTick_CALIB_NOREF_Pos            31U                                            /*!< SysTick CALIB: NOREF Position */
479  #define SysTick_CALIB_NOREF_Msk            (1UL << SysTick_CALIB_NOREF_Pos)               /*!< SysTick CALIB: NOREF Mask */
480  
481  #define SysTick_CALIB_SKEW_Pos             30U                                            /*!< SysTick CALIB: SKEW Position */
482  #define SysTick_CALIB_SKEW_Msk             (1UL << SysTick_CALIB_SKEW_Pos)                /*!< SysTick CALIB: SKEW Mask */
483  
484  #define SysTick_CALIB_TENMS_Pos             0U                                            /*!< SysTick CALIB: TENMS Position */
485  #define SysTick_CALIB_TENMS_Msk            (0xFFFFFFUL /*<< SysTick_CALIB_TENMS_Pos*/)    /*!< SysTick CALIB: TENMS Mask */
486  
487  /*@} end of group CMSIS_SysTick */
488  
489  
490  /**
491    \ingroup  CMSIS_core_register
492    \defgroup CMSIS_CoreDebug       Core Debug Registers (CoreDebug)
493    \brief    Cortex-M0 Core Debug Registers (DCB registers, SHCSR, and DFSR) are only accessible over DAP and not via processor.
494              Therefore they are not covered by the Cortex-M0 header file.
495    @{
496   */
497  /*@} end of group CMSIS_CoreDebug */
498  
499  
500  /**
501    \ingroup    CMSIS_core_register
502    \defgroup   CMSIS_core_bitfield     Core register bit field macros
503    \brief      Macros for use with bit field definitions (xxx_Pos, xxx_Msk).
504    @{
505   */
506  
507  /**
508    \brief   Mask and shift a bit field value for use in a register bit range.
509    \param[in] field  Name of the register bit field.
510    \param[in] value  Value of the bit field. This parameter is interpreted as an uint32_t type.
511    \return           Masked and shifted value.
512  */
513  #define _VAL2FLD(field, value)    (((uint32_t)(value) << field ## _Pos) & field ## _Msk)
514  
515  /**
516    \brief     Mask and shift a register value to extract a bit filed value.
517    \param[in] field  Name of the register bit field.
518    \param[in] value  Value of register. This parameter is interpreted as an uint32_t type.
519    \return           Masked and shifted bit field value.
520  */
521  #define _FLD2VAL(field, value)    (((uint32_t)(value) & field ## _Msk) >> field ## _Pos)
522  
523  /*@} end of group CMSIS_core_bitfield */
524  
525  
526  /**
527    \ingroup    CMSIS_core_register
528    \defgroup   CMSIS_core_base     Core Definitions
529    \brief      Definitions for base addresses, unions, and structures.
530    @{
531   */
532  
533  /* Memory mapping of Core Hardware */
534  #define SCS_BASE            (0xE000E000UL)                            /*!< System Control Space Base Address */
535  #define SysTick_BASE        (SCS_BASE +  0x0010UL)                    /*!< SysTick Base Address */
536  #define NVIC_BASE           (SCS_BASE +  0x0100UL)                    /*!< NVIC Base Address */
537  #define SCB_BASE            (SCS_BASE +  0x0D00UL)                    /*!< System Control Block Base Address */
538  
539  #define SCB                 ((SCB_Type       *)     SCB_BASE      )   /*!< SCB configuration struct */
540  #define SysTick             ((SysTick_Type   *)     SysTick_BASE  )   /*!< SysTick configuration struct */
541  #define NVIC                ((NVIC_Type      *)     NVIC_BASE     )   /*!< NVIC configuration struct */
542  
543  
544  /*@} */
545  
546  
547  
548  /*******************************************************************************
549   *                Hardware Abstraction Layer
550    Core Function Interface contains:
551    - Core NVIC Functions
552    - Core SysTick Functions
553    - Core Register Access Functions
554   ******************************************************************************/
555  /**
556    \defgroup CMSIS_Core_FunctionInterface Functions and Instructions Reference
557  */
558  
559  
560  
561  /* ##########################   NVIC functions  #################################### */
562  /**
563    \ingroup  CMSIS_Core_FunctionInterface
564    \defgroup CMSIS_Core_NVICFunctions NVIC Functions
565    \brief    Functions that manage interrupts and exceptions via the NVIC.
566    @{
567   */
568  
569  #ifdef CMSIS_NVIC_VIRTUAL
570    #ifndef CMSIS_NVIC_VIRTUAL_HEADER_FILE
571      #define CMSIS_NVIC_VIRTUAL_HEADER_FILE "cmsis_nvic_virtual.h"
572    #endif
573    #include CMSIS_NVIC_VIRTUAL_HEADER_FILE
574  #else
575    #define NVIC_SetPriorityGrouping    __NVIC_SetPriorityGrouping
576    #define NVIC_GetPriorityGrouping    __NVIC_GetPriorityGrouping
577    #define NVIC_EnableIRQ              __NVIC_EnableIRQ
578    #define NVIC_GetEnableIRQ           __NVIC_GetEnableIRQ
579    #define NVIC_DisableIRQ             __NVIC_DisableIRQ
580    #define NVIC_GetPendingIRQ          __NVIC_GetPendingIRQ
581    #define NVIC_SetPendingIRQ          __NVIC_SetPendingIRQ
582    #define NVIC_ClearPendingIRQ        __NVIC_ClearPendingIRQ
583  /*#define NVIC_GetActive              __NVIC_GetActive             not available for Cortex-M0 */
584    #define NVIC_SetPriority            __NVIC_SetPriority
585    #define NVIC_GetPriority            __NVIC_GetPriority
586    #define NVIC_SystemReset            __NVIC_SystemReset
587  #endif /* CMSIS_NVIC_VIRTUAL */
588  
589  #ifdef CMSIS_VECTAB_VIRTUAL
590    #ifndef CMSIS_VECTAB_VIRTUAL_HEADER_FILE
591      #define CMSIS_VECTAB_VIRTUAL_HEADER_FILE "cmsis_vectab_virtual.h"
592    #endif
593    #include CMSIS_VECTAB_VIRTUAL_HEADER_FILE
594  #else
595    #define NVIC_SetVector              __NVIC_SetVector
596    #define NVIC_GetVector              __NVIC_GetVector
597  #endif  /* (CMSIS_VECTAB_VIRTUAL) */
598  
599  #define NVIC_USER_IRQ_OFFSET          16
600  
601  
602  /* The following EXC_RETURN values are saved the LR on exception entry */
603  #define EXC_RETURN_HANDLER         (0xFFFFFFF1UL)     /* return to Handler mode, uses MSP after return                               */
604  #define EXC_RETURN_THREAD_MSP      (0xFFFFFFF9UL)     /* return to Thread mode, uses MSP after return                                */
605  #define EXC_RETURN_THREAD_PSP      (0xFFFFFFFDUL)     /* return to Thread mode, uses PSP after return                                */
606  
607  
608  /* Interrupt Priorities are WORD accessible only under Armv6-M                  */
609  /* The following MACROS handle generation of the register offset and byte masks */
610  #define _BIT_SHIFT(IRQn)         (  ((((uint32_t)(int32_t)(IRQn))         )      &  0x03UL) * 8UL)
611  #define _SHP_IDX(IRQn)           ( (((((uint32_t)(int32_t)(IRQn)) & 0x0FUL)-8UL) >>    2UL)      )
612  #define _IP_IDX(IRQn)            (   (((uint32_t)(int32_t)(IRQn))                >>    2UL)      )
613  
614  #define __NVIC_SetPriorityGrouping(X) (void)(X)
615  #define __NVIC_GetPriorityGrouping()  (0U)
616  
617  /**
618    \brief   Enable Interrupt
619    \details Enables a device specific interrupt in the NVIC interrupt controller.
620    \param [in]      IRQn  Device specific interrupt number.
621    \note    IRQn must not be negative.
622   */
623  __STATIC_INLINE void __NVIC_EnableIRQ(IRQn_Type IRQn)
624  {
625    if ((int32_t)(IRQn) >= 0)
626    {
627      __COMPILER_BARRIER();
628      NVIC->ISER[0U] = (uint32_t)(1UL << (((uint32_t)IRQn) & 0x1FUL));
629      __COMPILER_BARRIER();
630    }
631  }
632  
633  
634  /**
635    \brief   Get Interrupt Enable status
636    \details Returns a device specific interrupt enable status from the NVIC interrupt controller.
637    \param [in]      IRQn  Device specific interrupt number.
638    \return             0  Interrupt is not enabled.
639    \return             1  Interrupt is enabled.
640    \note    IRQn must not be negative.
641   */
642  __STATIC_INLINE uint32_t __NVIC_GetEnableIRQ(IRQn_Type IRQn)
643  {
644    if ((int32_t)(IRQn) >= 0)
645    {
646      return((uint32_t)(((NVIC->ISER[0U] & (1UL << (((uint32_t)IRQn) & 0x1FUL))) != 0UL) ? 1UL : 0UL));
647    }
648    else
649    {
650      return(0U);
651    }
652  }
653  
654  
655  /**
656    \brief   Disable Interrupt
657    \details Disables a device specific interrupt in the NVIC interrupt controller.
658    \param [in]      IRQn  Device specific interrupt number.
659    \note    IRQn must not be negative.
660   */
661  __STATIC_INLINE void __NVIC_DisableIRQ(IRQn_Type IRQn)
662  {
663    if ((int32_t)(IRQn) >= 0)
664    {
665      NVIC->ICER[0U] = (uint32_t)(1UL << (((uint32_t)IRQn) & 0x1FUL));
666      __DSB();
667      __ISB();
668    }
669  }
670  
671  
672  /**
673    \brief   Get Pending Interrupt
674    \details Reads the NVIC pending register and returns the pending bit for the specified device specific interrupt.
675    \param [in]      IRQn  Device specific interrupt number.
676    \return             0  Interrupt status is not pending.
677    \return             1  Interrupt status is pending.
678    \note    IRQn must not be negative.
679   */
680  __STATIC_INLINE uint32_t __NVIC_GetPendingIRQ(IRQn_Type IRQn)
681  {
682    if ((int32_t)(IRQn) >= 0)
683    {
684      return((uint32_t)(((NVIC->ISPR[0U] & (1UL << (((uint32_t)IRQn) & 0x1FUL))) != 0UL) ? 1UL : 0UL));
685    }
686    else
687    {
688      return(0U);
689    }
690  }
691  
692  
693  /**
694    \brief   Set Pending Interrupt
695    \details Sets the pending bit of a device specific interrupt in the NVIC pending register.
696    \param [in]      IRQn  Device specific interrupt number.
697    \note    IRQn must not be negative.
698   */
699  __STATIC_INLINE void __NVIC_SetPendingIRQ(IRQn_Type IRQn)
700  {
701    if ((int32_t)(IRQn) >= 0)
702    {
703      NVIC->ISPR[0U] = (uint32_t)(1UL << (((uint32_t)IRQn) & 0x1FUL));
704    }
705  }
706  
707  
708  /**
709    \brief   Clear Pending Interrupt
710    \details Clears the pending bit of a device specific interrupt in the NVIC pending register.
711    \param [in]      IRQn  Device specific interrupt number.
712    \note    IRQn must not be negative.
713   */
714  __STATIC_INLINE void __NVIC_ClearPendingIRQ(IRQn_Type IRQn)
715  {
716    if ((int32_t)(IRQn) >= 0)
717    {
718      NVIC->ICPR[0U] = (uint32_t)(1UL << (((uint32_t)IRQn) & 0x1FUL));
719    }
720  }
721  
722  
723  /**
724    \brief   Set Interrupt Priority
725    \details Sets the priority of a device specific interrupt or a processor exception.
726             The interrupt number can be positive to specify a device specific interrupt,
727             or negative to specify a processor exception.
728    \param [in]      IRQn  Interrupt number.
729    \param [in]  priority  Priority to set.
730    \note    The priority cannot be set for every processor exception.
731   */
732  __STATIC_INLINE void __NVIC_SetPriority(IRQn_Type IRQn, uint32_t priority)
733  {
734    if ((int32_t)(IRQn) >= 0)
735    {
736      NVIC->IP[_IP_IDX(IRQn)]  = ((uint32_t)(NVIC->IP[_IP_IDX(IRQn)]  & ~(0xFFUL << _BIT_SHIFT(IRQn))) |
737         (((priority << (8U - __NVIC_PRIO_BITS)) & (uint32_t)0xFFUL) << _BIT_SHIFT(IRQn)));
738    }
739    else
740    {
741      SCB->SHP[_SHP_IDX(IRQn)] = ((uint32_t)(SCB->SHP[_SHP_IDX(IRQn)] & ~(0xFFUL << _BIT_SHIFT(IRQn))) |
742         (((priority << (8U - __NVIC_PRIO_BITS)) & (uint32_t)0xFFUL) << _BIT_SHIFT(IRQn)));
743    }
744  }
745  
746  
747  /**
748    \brief   Get Interrupt Priority
749    \details Reads the priority of a device specific interrupt or a processor exception.
750             The interrupt number can be positive to specify a device specific interrupt,
751             or negative to specify a processor exception.
752    \param [in]   IRQn  Interrupt number.
753    \return             Interrupt Priority.
754                        Value is aligned automatically to the implemented priority bits of the microcontroller.
755   */
756  __STATIC_INLINE uint32_t __NVIC_GetPriority(IRQn_Type IRQn)
757  {
758  
759    if ((int32_t)(IRQn) >= 0)
760    {
761      return((uint32_t)(((NVIC->IP[ _IP_IDX(IRQn)] >> _BIT_SHIFT(IRQn) ) & (uint32_t)0xFFUL) >> (8U - __NVIC_PRIO_BITS)));
762    }
763    else
764    {
765      return((uint32_t)(((SCB->SHP[_SHP_IDX(IRQn)] >> _BIT_SHIFT(IRQn) ) & (uint32_t)0xFFUL) >> (8U - __NVIC_PRIO_BITS)));
766    }
767  }
768  
769  
770  /**
771    \brief   Encode Priority
772    \details Encodes the priority for an interrupt with the given priority group,
773             preemptive priority value, and subpriority value.
774             In case of a conflict between priority grouping and available
775             priority bits (__NVIC_PRIO_BITS), the smallest possible priority group is set.
776    \param [in]     PriorityGroup  Used priority group.
777    \param [in]   PreemptPriority  Preemptive priority value (starting from 0).
778    \param [in]       SubPriority  Subpriority value (starting from 0).
779    \return                        Encoded priority. Value can be used in the function \ref NVIC_SetPriority().
780   */
781  __STATIC_INLINE uint32_t NVIC_EncodePriority (uint32_t PriorityGroup, uint32_t PreemptPriority, uint32_t SubPriority)
782  {
783    uint32_t PriorityGroupTmp = (PriorityGroup & (uint32_t)0x07UL);   /* only values 0..7 are used          */
784    uint32_t PreemptPriorityBits;
785    uint32_t SubPriorityBits;
786  
787    PreemptPriorityBits = ((7UL - PriorityGroupTmp) > (uint32_t)(__NVIC_PRIO_BITS)) ? (uint32_t)(__NVIC_PRIO_BITS) : (uint32_t)(7UL - PriorityGroupTmp);
788    SubPriorityBits     = ((PriorityGroupTmp + (uint32_t)(__NVIC_PRIO_BITS)) < (uint32_t)7UL) ? (uint32_t)0UL : (uint32_t)((PriorityGroupTmp - 7UL) + (uint32_t)(__NVIC_PRIO_BITS));
789  
790    return (
791             ((PreemptPriority & (uint32_t)((1UL << (PreemptPriorityBits)) - 1UL)) << SubPriorityBits) |
792             ((SubPriority     & (uint32_t)((1UL << (SubPriorityBits    )) - 1UL)))
793           );
794  }
795  
796  
797  /**
798    \brief   Decode Priority
799    \details Decodes an interrupt priority value with a given priority group to
800             preemptive priority value and subpriority value.
801             In case of a conflict between priority grouping and available
802             priority bits (__NVIC_PRIO_BITS) the smallest possible priority group is set.
803    \param [in]         Priority   Priority value, which can be retrieved with the function \ref NVIC_GetPriority().
804    \param [in]     PriorityGroup  Used priority group.
805    \param [out] pPreemptPriority  Preemptive priority value (starting from 0).
806    \param [out]     pSubPriority  Subpriority value (starting from 0).
807   */
808  __STATIC_INLINE void NVIC_DecodePriority (uint32_t Priority, uint32_t PriorityGroup, uint32_t* const pPreemptPriority, uint32_t* const pSubPriority)
809  {
810    uint32_t PriorityGroupTmp = (PriorityGroup & (uint32_t)0x07UL);   /* only values 0..7 are used          */
811    uint32_t PreemptPriorityBits;
812    uint32_t SubPriorityBits;
813  
814    PreemptPriorityBits = ((7UL - PriorityGroupTmp) > (uint32_t)(__NVIC_PRIO_BITS)) ? (uint32_t)(__NVIC_PRIO_BITS) : (uint32_t)(7UL - PriorityGroupTmp);
815    SubPriorityBits     = ((PriorityGroupTmp + (uint32_t)(__NVIC_PRIO_BITS)) < (uint32_t)7UL) ? (uint32_t)0UL : (uint32_t)((PriorityGroupTmp - 7UL) + (uint32_t)(__NVIC_PRIO_BITS));
816  
817    *pPreemptPriority = (Priority >> SubPriorityBits) & (uint32_t)((1UL << (PreemptPriorityBits)) - 1UL);
818    *pSubPriority     = (Priority                   ) & (uint32_t)((1UL << (SubPriorityBits    )) - 1UL);
819  }
820  
821  
822  
823  /**
824    \brief   Set Interrupt Vector
825    \details Sets an interrupt vector in SRAM based interrupt vector table.
826             The interrupt number can be positive to specify a device specific interrupt,
827             or negative to specify a processor exception.
828             Address 0 must be mapped to SRAM.
829    \param [in]   IRQn      Interrupt number
830    \param [in]   vector    Address of interrupt handler function
831   */
832  __STATIC_INLINE void __NVIC_SetVector(IRQn_Type IRQn, uint32_t vector)
833  {
834    uint32_t *vectors = (uint32_t *)(NVIC_USER_IRQ_OFFSET << 2);      /* point to 1st user interrupt */
835    *(vectors + (int32_t)IRQn) = vector;                              /* use pointer arithmetic to access vector */
836    /* ARM Application Note 321 states that the M0 does not require the architectural barrier */
837  }
838  
839  
840  /**
841    \brief   Get Interrupt Vector
842    \details Reads an interrupt vector from interrupt vector table.
843             The interrupt number can be positive to specify a device specific interrupt,
844             or negative to specify a processor exception.
845    \param [in]   IRQn      Interrupt number.
846    \return                 Address of interrupt handler function
847   */
848  __STATIC_INLINE uint32_t __NVIC_GetVector(IRQn_Type IRQn)
849  {
850    uint32_t *vectors = (uint32_t *)(NVIC_USER_IRQ_OFFSET << 2);      /* point to 1st user interrupt */
851    return *(vectors + (int32_t)IRQn);                                /* use pointer arithmetic to access vector */
852  }
853  
854  
855  /**
856    \brief   System Reset
857    \details Initiates a system reset request to reset the MCU.
858   */
859  __NO_RETURN __STATIC_INLINE void __NVIC_SystemReset(void)
860  {
861    __DSB();                                                          /* Ensure all outstanding memory accesses included
862                                                                         buffered write are completed before reset */
863    SCB->AIRCR  = ((0x5FAUL << SCB_AIRCR_VECTKEY_Pos) |
864                   SCB_AIRCR_SYSRESETREQ_Msk);
865    __DSB();                                                          /* Ensure completion of memory access */
866  
867    for(;;)                                                           /* wait until reset */
868    {
869      __NOP();
870    }
871  }
872  
873  /*@} end of CMSIS_Core_NVICFunctions */
874  
875  
876  /* ##########################  FPU functions  #################################### */
877  /**
878    \ingroup  CMSIS_Core_FunctionInterface
879    \defgroup CMSIS_Core_FpuFunctions FPU Functions
880    \brief    Function that provides FPU type.
881    @{
882   */
883  
884  /**
885    \brief   get FPU type
886    \details returns the FPU type
887    \returns
888     - \b  0: No FPU
889     - \b  1: Single precision FPU
890     - \b  2: Double + Single precision FPU
891   */
892  __STATIC_INLINE uint32_t SCB_GetFPUType(void)
893  {
894      return 0U;           /* No FPU */
895  }
896  
897  
898  /*@} end of CMSIS_Core_FpuFunctions */
899  
900  
901  
902  /* ##################################    SysTick function  ############################################ */
903  /**
904    \ingroup  CMSIS_Core_FunctionInterface
905    \defgroup CMSIS_Core_SysTickFunctions SysTick Functions
906    \brief    Functions that configure the System.
907    @{
908   */
909  
910  #if defined (__Vendor_SysTickConfig) && (__Vendor_SysTickConfig == 0U)
911  
912  /**
913    \brief   System Tick Configuration
914    \details Initializes the System Timer and its interrupt, and starts the System Tick Timer.
915             Counter is in free running mode to generate periodic interrupts.
916    \param [in]  ticks  Number of ticks between two interrupts.
917    \return          0  Function succeeded.
918    \return          1  Function failed.
919    \note    When the variable <b>__Vendor_SysTickConfig</b> is set to 1, then the
920             function <b>SysTick_Config</b> is not included. In this case, the file <b><i>device</i>.h</b>
921             must contain a vendor-specific implementation of this function.
922   */
923  __STATIC_INLINE uint32_t SysTick_Config(uint32_t ticks)
924  {
925    if ((ticks - 1UL) > SysTick_LOAD_RELOAD_Msk)
926    {
927      return (1UL);                                                   /* Reload value impossible */
928    }
929  
930    SysTick->LOAD  = (uint32_t)(ticks - 1UL);                         /* set reload register */
931    NVIC_SetPriority (SysTick_IRQn, (1UL << __NVIC_PRIO_BITS) - 1UL); /* set Priority for Systick Interrupt */
932    SysTick->VAL   = 0UL;                                             /* Load the SysTick Counter Value */
933    SysTick->CTRL  = SysTick_CTRL_CLKSOURCE_Msk |
934                     SysTick_CTRL_TICKINT_Msk   |
935                     SysTick_CTRL_ENABLE_Msk;                         /* Enable SysTick IRQ and SysTick Timer */
936    return (0UL);                                                     /* Function successful */
937  }
938  
939  #endif
940  
941  /*@} end of CMSIS_Core_SysTickFunctions */
942  
943  
944  
945  
946  #ifdef __cplusplus
947  }
948  #endif
949  
950  #endif /* __CORE_CM0_H_DEPENDANT */
951  
952  #endif /* __CMSIS_GENERIC */