rt-thread/bsp/at32/at32m416-start/board/src/board.c

/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2024-08-30     shelton      first version
 */

#include "board.h"

void system_clock_config(void)
{
  /* reset crm */
  crm_reset();

  /* config flash psr register */
  flash_psr_set(FLASH_WAIT_CYCLE_5);

  /* enable pwc periph clock */
  crm_periph_clock_enable(CRM_PWC_PERIPH_CLOCK, TRUE);

  /* set power ldo output voltage to 1.3v */
  pwc_ldo_output_voltage_set(PWC_LDO_OUTPUT_1V3);

  crm_clock_source_enable(CRM_CLOCK_SOURCE_HEXT, TRUE);

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

  /* if pll parameter has changed, please use the AT32_New_Clock_Configuration tool for new configuration. */
  crm_pll_config(CRM_PLL_SOURCE_HEXT, 90, 1, CRM_PLL_FR_4);

  /* 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 apb3clk, the maximum frequency of APB3 clock is 90 MHz */
  crm_apb3_div_set(CRM_APB3_DIV_4);

  /* config apb2clk, the maximum frequency of APB2 clock is 180 MHz */
  crm_apb2_div_set(CRM_APB2_DIV_1);

  /* config apb1clk, the maximum frequency of APB1 clock is 180 MHz */
  crm_apb1_div_set(CRM_APB1_DIV_1);

  /* 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();
}