1 /**************************************************************************//**
2 * @file system_ARMCM3.c
3 * @brief CMSIS Device System Source File for
4 * ARMCM3 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 #include "ARMCM3.h"
27
28 /*----------------------------------------------------------------------------
29 Define clocks
30 *----------------------------------------------------------------------------*/
31 #define XTAL (50000000UL) /* Oscillator frequency */
32
33 #define SYSTEM_CLOCK (XTAL / 2U)
34
35 /*----------------------------------------------------------------------------
36 Exception / Interrupt Vector table
37 *----------------------------------------------------------------------------*/
38 extern const VECTOR_TABLE_Type __VECTOR_TABLE[240];
39
40 /*----------------------------------------------------------------------------
41 System Core Clock Variable
42 *----------------------------------------------------------------------------*/
43 uint32_t SystemCoreClock = SYSTEM_CLOCK; /* System Core Clock Frequency */
44
45
46 /*----------------------------------------------------------------------------
47 System Core Clock update function
48 *----------------------------------------------------------------------------*/
SystemCoreClockUpdate(void)49 void SystemCoreClockUpdate (void)
50 {
51 SystemCoreClock = SYSTEM_CLOCK;
52 }
53
54 /*----------------------------------------------------------------------------
55 System initialization function
56 *----------------------------------------------------------------------------*/
SystemInit(void)57 void SystemInit (void)
58 {
59
60 #if defined (__VTOR_PRESENT) && (__VTOR_PRESENT == 1U)
61 SCB->VTOR = (uint32_t) &(__VECTOR_TABLE[0]);
62 #endif
63
64 SystemCoreClock = SYSTEM_CLOCK;
65 }
66
