1 /*
2  * Copyright (c) 2006-2021, RT-Thread Development Team
3  *
4  * SPDX-License-Identifier: Apache-2.0
5  *
6  * Change Logs:
7  * Date           Author       Notes
8  * 2022-03-28     shelton      first version
9  */
10 
11 #include "board.h"
12 
system_clock_config(void)13 void system_clock_config(void)
14 {
15   /* enable pwc periph clock */
16   crm_periph_clock_enable(CRM_PWC_PERIPH_CLOCK, TRUE);
17 
18   /* config ldo voltage */
19   pwc_ldo_output_voltage_set(PWC_LDO_OUTPUT_1V3);
20 
21   /* set the flash clock divider */
22   flash_clock_divider_set(FLASH_CLOCK_DIV_3);
23 
24   /* reset crm */
25   crm_reset();
26 
27   crm_clock_source_enable(CRM_CLOCK_SOURCE_HEXT, TRUE);
28 
29   /* wait till hext is ready */
30   while(crm_hext_stable_wait() == ERROR)
31   {
32   }
33 
34   /* config pll clock resource */
35   crm_pll_config(CRM_PLL_SOURCE_HEXT, 144, 1, CRM_PLL_FR_4);
36 
37   /* enable pll */
38   crm_clock_source_enable(CRM_CLOCK_SOURCE_PLL, TRUE);
39 
40   /* wait till pll is ready */
41   while(crm_flag_get(CRM_PLL_STABLE_FLAG) != SET)
42   {
43   }
44 
45   /* config ahbclk */
46   crm_ahb_div_set(CRM_AHB_DIV_1);
47 
48   /* config apb2clk */
49   crm_apb2_div_set(CRM_APB2_DIV_2);
50 
51   /* config apb1clk */
52   crm_apb1_div_set(CRM_APB1_DIV_2);
53 
54   /* enable auto step mode */
55   crm_auto_step_mode_enable(TRUE);
56 
57   /* select pll as system clock source */
58   crm_sysclk_switch(CRM_SCLK_PLL);
59 
60   /* wait till pll is used as system clock source */
61   while(crm_sysclk_switch_status_get() != CRM_SCLK_PLL)
62   {
63   }
64 
65   /* disable auto step mode */
66   crm_auto_step_mode_enable(FALSE);
67 
68   /* update system_core_clock global variable */
69   system_core_clock_update();
70 }
71