1 /**************************************************************************//**
2 * @file system_ARMCM4.c
3 * @brief CMSIS Device System Source File for
4 * ARMCM4 Device
5 * @version V2.0.0
6 * @date 06. April 2023
7 ******************************************************************************/
8 /*
9 * Copyright (c) 2009-2023 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 #else
29 #error device not specified!
30 #endif
31
32 /*----------------------------------------------------------------------------
33 Define clocks
34 *----------------------------------------------------------------------------*/
35 #define XTAL (50000000UL) /* Oscillator frequency */
36
37 #define SYSTEM_CLOCK (XTAL / 2U)
38
39 /*----------------------------------------------------------------------------
40 Exception / Interrupt Vector table
41 *----------------------------------------------------------------------------*/
42 extern const VECTOR_TABLE_Type __VECTOR_TABLE[240];
43
44
45 /*----------------------------------------------------------------------------
46 System Core Clock Variable
47 *----------------------------------------------------------------------------*/
48 uint32_t SystemCoreClock = SYSTEM_CLOCK; /* System Core Clock Frequency */
49
50
51 /*----------------------------------------------------------------------------
52 System Core Clock update function
53 *----------------------------------------------------------------------------*/
SystemCoreClockUpdate(void)54 void SystemCoreClockUpdate (void)
55 {
56 SystemCoreClock = SYSTEM_CLOCK;
57 }
58
59 /*----------------------------------------------------------------------------
60 System initialization function
61 *----------------------------------------------------------------------------*/
SystemInit(void)62 void SystemInit (void)
63 {
64
65 #if defined (__VTOR_PRESENT) && (__VTOR_PRESENT == 1U)
66 SCB->VTOR = (uint32_t) &(__VECTOR_TABLE[0]);
67 #endif
68
69 #if defined (__FPU_USED) && (__FPU_USED == 1U)
70 SCB->CPACR |= ((3U << 10U*2U) | /* enable CP10 Full Access */
71 (3U << 11U*2U) ); /* enable CP11 Full Access */
72 #endif
73
74 #ifdef UNALIGNED_SUPPORT_DISABLE
75 SCB->CCR |= SCB_CCR_UNALIGN_TRP_Msk;
76 #endif
77
78 SystemCoreClock = SYSTEM_CLOCK;
79 }
80
