File content as of revision 148:161ebc35dc3a:

/*
** ###################################################################
**     Processors:          MK22FN512CAP12
**                          MK22FN512VDC12
**                          MK22FN512VLH12
**                          MK22FN512VLL12
**                          MK22FN512VMP12
**
**     Compilers:           Keil ARM C/C++ Compiler
**                          Freescale C/C++ for Embedded ARM
**                          GNU C Compiler
**                          IAR ANSI C/C++ Compiler for ARM
**
**     Reference manual:    K22P121M120SF7RM, Rev. 1, March 24, 2014
**     Version:             rev. 2.8, 2015-02-19
**     Build:               b151217
**
**     Abstract:
**         Provides a system configuration function and a global variable that
**         contains the system frequency. It configures the device and initializes
**         the oscillator (PLL) that is part of the microcontroller device.
**
**     Copyright (c) 2015 Freescale Semiconductor, Inc.
**     All rights reserved.
**
**     Redistribution and use in source and binary forms, with or without modification,
**     are permitted provided that the following conditions are met:
**
**     o Redistributions of source code must retain the above copyright notice, this list
**       of conditions and the following disclaimer.
**
**     o Redistributions in binary form must reproduce the above copyright notice, this
**       list of conditions and the following disclaimer in the documentation and/or
**       other materials provided with the distribution.
**
**     o Neither the name of Freescale Semiconductor, Inc. nor the names of its
**       contributors may be used to endorse or promote products derived from this
**       software without specific prior written permission.
**
**     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
**     ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
**     WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
**     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
**     ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
**     (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
**     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
**     ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
**     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
**     SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**
**     http:                 www.freescale.com
**     mail:                 support@freescale.com
**
**     Revisions:
**     - rev. 1.0 (2013-07-23)
**         Initial version.
**     - rev. 1.1 (2013-09-17)
**         RM rev. 0.4 update.
**     - rev. 2.0 (2013-10-29)
**         Register accessor macros added to the memory map.
**         Symbols for Processor Expert memory map compatibility added to the memory map.
**         Startup file for gcc has been updated according to CMSIS 3.2.
**         System initialization updated.
**     - rev. 2.1 (2013-10-30)
**         Definition of BITBAND macros updated to support peripherals with 32-bit acces disabled.
**     - rev. 2.2 (2013-12-20)
**         Update according to reference manual rev. 0.6,
**     - rev. 2.3 (2014-01-13)
**         Update according to reference manual rev. 0.61,
**     - rev. 2.4 (2014-02-10)
**         The declaration of clock configurations has been moved to separate header file system_MK22F51212.h
**     - rev. 2.5 (2014-05-06)
**         Update according to reference manual rev. 1.0,
**         Update of system and startup files.
**         Module access macro module_BASES replaced by module_BASE_PTRS.
**     - rev. 2.6 (2014-08-28)
**         Update of system files - default clock configuration changed.
**         Update of startup files - possibility to override DefaultISR added.
**     - rev. 2.7 (2014-10-14)
**         Interrupt INT_LPTimer renamed to INT_LPTMR0, interrupt INT_Watchdog renamed to INT_WDOG_EWM.
**     - rev. 2.8 (2015-02-19)
**         Renamed interrupt vector LLW to LLWU.
**
** ###################################################################
*/

/*!
 * @file MK22F51212
 * @version 2.8
 * @date 2015-02-19
 * @brief Device specific configuration file for MK22F51212 (implementation file)
 *
 * Provides a system configuration function and a global variable that contains
 * the system frequency. It configures the device and initializes the oscillator
 * (PLL) that is part of the microcontroller device.
 */

#include <stdint.h>
#include "fsl_device_registers.h"



/* ----------------------------------------------------------------------------
   -- Core clock
   ---------------------------------------------------------------------------- */

uint32_t SystemCoreClock = DEFAULT_SYSTEM_CLOCK;

/* ----------------------------------------------------------------------------
   -- SystemInit()
   ---------------------------------------------------------------------------- */

void SystemInit (void) {
#if ((__FPU_PRESENT == 1) && (__FPU_USED == 1))
  SCB->CPACR |= ((3UL << 10*2) | (3UL << 11*2));    /* set CP10, CP11 Full Access */
#endif /* ((__FPU_PRESENT == 1) && (__FPU_USED == 1)) */

#if (DISABLE_WDOG)
  /* WDOG->UNLOCK: WDOGUNLOCK=0xC520 */
  WDOG->UNLOCK = WDOG_UNLOCK_WDOGUNLOCK(0xC520); /* Key 1 */
  /* WDOG->UNLOCK: WDOGUNLOCK=0xD928 */
  WDOG->UNLOCK = WDOG_UNLOCK_WDOGUNLOCK(0xD928); /* Key 2 */
  /* WDOG->STCTRLH: ?=0,DISTESTWDOG=0,BYTESEL=0,TESTSEL=0,TESTWDOG=0,?=0,?=1,WAITEN=1,STOPEN=1,DBGEN=0,ALLOWUPDATE=1,WINEN=0,IRQRSTEN=0,CLKSRC=1,WDOGEN=0 */
  WDOG->STCTRLH = WDOG_STCTRLH_BYTESEL(0x00) |
                 WDOG_STCTRLH_WAITEN_MASK |
                 WDOG_STCTRLH_STOPEN_MASK |
                 WDOG_STCTRLH_ALLOWUPDATE_MASK |
                 WDOG_STCTRLH_CLKSRC_MASK |
                 0x0100U;
#endif /* (DISABLE_WDOG) */

}

/* ----------------------------------------------------------------------------
   -- SystemCoreClockUpdate()
   ---------------------------------------------------------------------------- */

void SystemCoreClockUpdate (void) {

  uint32_t MCGOUTClock;                /* Variable to store output clock frequency of the MCG module */
  uint16_t Divider;

  if ((MCG->C1 & MCG_C1_CLKS_MASK) == 0x00U) {
    /* Output of FLL or PLL is selected */
    if ((MCG->C6 & MCG_C6_PLLS_MASK) == 0x00U) {
      /* FLL is selected */
      if ((MCG->C1 & MCG_C1_IREFS_MASK) == 0x00U) {
        /* External reference clock is selected */
        switch (MCG->C7 & MCG_C7_OSCSEL_MASK) {
        case 0x00U:
          MCGOUTClock = CPU_XTAL_CLK_HZ; /* System oscillator drives MCG clock */
          break;
        case 0x01U:
          MCGOUTClock = CPU_XTAL32k_CLK_HZ; /* RTC 32 kHz oscillator drives MCG clock */
          break;
        case 0x02U:
        default:
          MCGOUTClock = CPU_INT_IRC_CLK_HZ; /* IRC 48MHz oscillator drives MCG clock */
          break;
        }
        if (((MCG->C2 & MCG_C2_RANGE_MASK) != 0x00U) && ((MCG->C7 & MCG_C7_OSCSEL_MASK) != 0x01U)) {
          switch (MCG->C1 & MCG_C1_FRDIV_MASK) {
          case 0x38U:
            Divider = 1536U;
            break;
          case 0x30U:
            Divider = 1280U;
            break;
          default:
            Divider = (uint16_t)(32LU << ((MCG->C1 & MCG_C1_FRDIV_MASK) >> MCG_C1_FRDIV_SHIFT));
            break;
          }
        } else {/* ((MCG->C2 & MCG_C2_RANGE_MASK) != 0x00U) */
          Divider = (uint16_t)(1LU << ((MCG->C1 & MCG_C1_FRDIV_MASK) >> MCG_C1_FRDIV_SHIFT));
        }
        MCGOUTClock = (MCGOUTClock / Divider); /* Calculate the divided FLL reference clock */
      } else { /* (!((MCG->C1 & MCG_C1_IREFS_MASK) == 0x00U)) */
        MCGOUTClock = CPU_INT_SLOW_CLK_HZ; /* The slow internal reference clock is selected */
      } /* (!((MCG->C1 & MCG_C1_IREFS_MASK) == 0x00U)) */
      /* Select correct multiplier to calculate the MCG output clock  */
      switch (MCG->C4 & (MCG_C4_DMX32_MASK | MCG_C4_DRST_DRS_MASK)) {
        case 0x00U:
          MCGOUTClock *= 640U;
          break;
        case 0x20U:
          MCGOUTClock *= 1280U;
          break;
        case 0x40U:
          MCGOUTClock *= 1920U;
          break;
        case 0x60U:
          MCGOUTClock *= 2560U;
          break;
        case 0x80U:
          MCGOUTClock *= 732U;
          break;
        case 0xA0U:
          MCGOUTClock *= 1464U;
          break;
        case 0xC0U:
          MCGOUTClock *= 2197U;
          break;
        case 0xE0U:
          MCGOUTClock *= 2929U;
          break;
        default:
          break;
      }
    } else { /* (!((MCG->C6 & MCG_C6_PLLS_MASK) == 0x00U)) */
      /* PLL is selected */
      Divider = (((uint16_t)MCG->C5 & MCG_C5_PRDIV0_MASK) + 0x01U);
      MCGOUTClock = (uint32_t)(CPU_XTAL_CLK_HZ / Divider); /* Calculate the PLL reference clock */
      Divider = (((uint16_t)MCG->C6 & MCG_C6_VDIV0_MASK) + 24U);
      MCGOUTClock *= Divider;          /* Calculate the MCG output clock */
    } /* (!((MCG->C6 & MCG_C6_PLLS_MASK) == 0x00U)) */
  } else if ((MCG->C1 & MCG_C1_CLKS_MASK) == 0x40U) {
    /* Internal reference clock is selected */
    if ((MCG->C2 & MCG_C2_IRCS_MASK) == 0x00U) {
      MCGOUTClock = CPU_INT_SLOW_CLK_HZ; /* Slow internal reference clock selected */
    } else { /* (!((MCG->C2 & MCG_C2_IRCS_MASK) == 0x00U)) */
      Divider = (uint16_t)(0x01LU << ((MCG->SC & MCG_SC_FCRDIV_MASK) >> MCG_SC_FCRDIV_SHIFT));
      MCGOUTClock = (uint32_t) (CPU_INT_FAST_CLK_HZ / Divider); /* Fast internal reference clock selected */
    } /* (!((MCG->C2 & MCG_C2_IRCS_MASK) == 0x00U)) */
  } else if ((MCG->C1 & MCG_C1_CLKS_MASK) == 0x80U) {
    /* External reference clock is selected */
    switch (MCG->C7 & MCG_C7_OSCSEL_MASK) {
    case 0x00U:
      MCGOUTClock = CPU_XTAL_CLK_HZ;   /* System oscillator drives MCG clock */
      break;
    case 0x01U:
      MCGOUTClock = CPU_XTAL32k_CLK_HZ; /* RTC 32 kHz oscillator drives MCG clock */
      break;
    case 0x02U:
    default:
      MCGOUTClock = CPU_INT_IRC_CLK_HZ; /* IRC 48MHz oscillator drives MCG clock */
      break;
    }
  } else { /* (!((MCG->C1 & MCG_C1_CLKS_MASK) == 0x80U)) */
    /* Reserved value */
    return;
  } /* (!((MCG->C1 & MCG_C1_CLKS_MASK) == 0x80U)) */
  SystemCoreClock = (MCGOUTClock / (0x01U + ((SIM->CLKDIV1 & SIM_CLKDIV1_OUTDIV1_MASK) >> SIM_CLKDIV1_OUTDIV1_SHIFT)));
}