CRM — 系统时钟切换

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171

#include "at32f403a_407_board.h"
#include "at32f403a_407_clock.h"

static void clkout_config(void);
static void sclk_64m_hick_config(void);
static void sclk_96m_hext_config(void);
static void switch_system_clock(void);

/**
  * @brief  clkout configuration.
  * @param  none
  * @retval none
  */
void clkout_config(void)
{
  gpio_init_type gpio_init_struct;

  /* enable gpio port clock */
  crm_periph_clock_enable(CRM_GPIOA_PERIPH_CLOCK, TRUE);

  /* set default parameter */
  gpio_default_para_init(&gpio_init_struct);

  /* clkout gpio init */
  gpio_init_struct.gpio_drive_strength = GPIO_DRIVE_STRENGTH_STRONGER;
  gpio_init_struct.gpio_mode = GPIO_MODE_MUX;
  gpio_init_struct.gpio_pins = GPIO_PINS_8;
  gpio_init_struct.gpio_pull = GPIO_PULL_NONE;
  gpio_init(GPIOA, &gpio_init_struct);

  /* config clkout division */
  crm_clkout_div_set(CRM_CLKOUT_DIV_1);

  /* config clkout clock */
  crm_clock_out_set(CRM_CLKOUT_PLL_DIV_4);
}

static void sclk_64m_hick_config(void)
{
  /* reset crm */
  crm_reset();

  crm_clock_source_enable(CRM_CLOCK_SOURCE_HICK, TRUE);

   /* wait till hick is ready */
  while(crm_flag_get(CRM_HICK_STABLE_FLAG) != SET)
  {
  }

  /* config pll clock resource */
  crm_pll_config(CRM_PLL_SOURCE_HICK, CRM_PLL_MULT_16, CRM_PLL_OUTPUT_RANGE_LE72MHZ);

  /* enable pll */
  crm_clock_source_enable(CRM_CLOCK_SOURCE_PLL, TRUE);

  /* wait till pll is ready */
  while(crm_flag_get(CRM_PLL_STABLE_FLAG) != SET)
  {
  }

  /* config ahbclk */
  crm_ahb_div_set(CRM_AHB_DIV_1);

  /* config apb2clk, the maximum frequency of APB1/APB2 clock is 120 MHz */
  crm_apb2_div_set(CRM_APB2_DIV_2);

  /* config apb1clk, the maximum frequency of APB1/APB2 clock is 120 MHz  */
  crm_apb1_div_set(CRM_APB1_DIV_2);

  /* enable auto step mode */
  crm_auto_step_mode_enable(TRUE);

  /* select pll as system clock source */
  crm_sysclk_switch(CRM_SCLK_PLL);

  /* wait till pll is used as system clock source */
  while(crm_sysclk_switch_status_get() != CRM_SCLK_PLL)
  {
  }

  /* disable auto step mode */
  crm_auto_step_mode_enable(FALSE);

  /* update system_core_clock global variable */
  system_core_clock_update();

  /* config systick delay */
  delay_init();

  /* config clkout */
  clkout_config();
}

static void sclk_96m_hext_config(void)
{
  /* reset crm */
  crm_reset();

  crm_clock_source_enable(CRM_CLOCK_SOURCE_HEXT, TRUE);

   /* wait till hext is ready */
  while(crm_hext_stable_wait() == ERROR)
  {
  }

  /* config pll clock resource */
  crm_pll_config(CRM_PLL_SOURCE_HEXT_DIV, CRM_PLL_MULT_24, CRM_PLL_OUTPUT_RANGE_GT72MHZ);

  /* config hext division */
  crm_hext_clock_div_set(CRM_HEXT_DIV_2);

  /* enable pll */
  crm_clock_source_enable(CRM_CLOCK_SOURCE_PLL, TRUE);

  /* wait till pll is ready */
  while(crm_flag_get(CRM_PLL_STABLE_FLAG) != SET)
  {
  }

  /* config ahbclk */
  crm_ahb_div_set(CRM_AHB_DIV_1);

  /* config apb2clk, the maximum frequency of APB1/APB2 clock is 120 MHz */
  crm_apb2_div_set(CRM_APB2_DIV_2);

  /* config apb1clk, the maximum frequency of APB1/APB2 clock is 120 MHz  */
  crm_apb1_div_set(CRM_APB1_DIV_2);

  /* enable auto step mode */
  crm_auto_step_mode_enable(TRUE);

  /* select pll as system clock source */
  crm_sysclk_switch(CRM_SCLK_PLL);

  /* wait till pll is used as system clock source */
  while(crm_sysclk_switch_status_get() != CRM_SCLK_PLL)
  {
  }

  /* disable auto step mode */
  crm_auto_step_mode_enable(FALSE);

  /* update system_core_clock global variable */
  system_core_clock_update();

  /* config systick delay */
  delay_init();

  /* config clkout */
  clkout_config();
}

int main(void)
{
  system_clock_config();

  at32_board_init();

  clkout_config();

  while(1)
  {
    if(at32_button_press() == USER_BUTTON)
    {
      switch_system_clock();
      at32_led_toggle(LED4);
    }
    at32_led_toggle(LED2);
    delay_ms(100);
  }
}