1 /**************************************************************************//**
2 * @file system_ARMCM4.c
3 * @brief CMSIS Device System Source File for
4 * ARMCM4 Device
5 * @version V1.0.1
6 * @date 15. November 2019
7 ******************************************************************************/
8 /*
9 * Copyright (c) 2009-2019 Arm Limited. All rights reserved.
10 *
11 * SPDX-License-Identifier: Apache-2.0
12 *
13 * Licensed under the Apache License, Version 2.0 (the License); you may
14 * not use this file except in compliance with the License.
15 * You may obtain a copy of the License at
16 *
17 * www.apache.org/licenses/LICENSE-2.0
18 *
19 * Unless required by applicable law or agreed to in writing, software
20 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
21 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
22 * See the License for the specific language governing permissions and
23 * limitations under the License.
24 */
25
26 #if defined (ARMCM4)
27 #include "ARMCM4.h"
28 #elif defined (ARMCM4_FP)
29 #include "ARMCM4_FP.h"
30 #else
31 #error device not specified!
32 #endif
33
34 /*----------------------------------------------------------------------------
35 Define clocks
36 *----------------------------------------------------------------------------*/
37 #define XTAL (50000000UL) /* Oscillator frequency */
38
39 #define SYSTEM_CLOCK (XTAL / 2U)
40
41 /*----------------------------------------------------------------------------
42 Exception / Interrupt Vector table
43 *----------------------------------------------------------------------------*/
44 extern const VECTOR_TABLE_Type __VECTOR_TABLE[240];
45
46
47 /*----------------------------------------------------------------------------
48 System Core Clock Variable
49 *----------------------------------------------------------------------------*/
50 uint32_t SystemCoreClock = SYSTEM_CLOCK; /* System Core Clock Frequency */
51
52
53 /*----------------------------------------------------------------------------
54 System Core Clock update function
55 *----------------------------------------------------------------------------*/
SystemCoreClockUpdate(void)56 void SystemCoreClockUpdate (void)
57 {
58 SystemCoreClock = SYSTEM_CLOCK;
59 }
60
61 /*----------------------------------------------------------------------------
62 System initialization function
63 *----------------------------------------------------------------------------*/
SystemInit(void)64 void SystemInit (void)
65 {
66
67 #if defined (__VTOR_PRESENT) && (__VTOR_PRESENT == 1U)
68 SCB->VTOR = (uint32_t) &(__VECTOR_TABLE[0]);
69 #endif
70
71 #if defined (__FPU_USED) && (__FPU_USED == 1U)
72 SCB->CPACR |= ((3U << 10U*2U) | /* enable CP10 Full Access */
73 (3U << 11U*2U) ); /* enable CP11 Full Access */
74 #endif
75
76 #ifdef UNALIGNED_SUPPORT_DISABLE
77 SCB->CCR |= SCB_CCR_UNALIGN_TRP_Msk;
78 #endif
79
80 SystemCoreClock = SYSTEM_CLOCK;
81 }
82
