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/*
** ###################################################################
** Compilers: ARM Compiler
** Freescale C/C++ for Embedded ARM
** GNU C Compiler
** IAR ANSI C/C++ Compiler for ARM
**
** Reference manuals: K20P64M50SF0RM Rev. 1, Oct 2011
** K20P32M50SF0RM Rev. 1, Oct 2011
** K20P48M50SF0RM Rev. 1, Oct 2011
**
** Version: rev. 1.0, 2011-12-15
**
** 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: 2011 Freescale Semiconductor, Inc. All Rights Reserved.
**
** http: www.freescale.com
** mail: support@freescale.com
**
** Revisions:
** - rev. 1.0 (2011-12-15)
** Initial version
**
** ###################################################################
*/
/**
* @file MK20D5
* @version 1.0
* @date 2011-12-15
* @brief Device specific configuration file for MK20D5 (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 "MK20D5.h"
#define DISABLE_WDOG 1
#define CLOCK_SETUP 3
/* Predefined clock setups
0 ... Multipurpose Clock Generator (MCG) in FLL Engaged Internal (FEI) mode
Reference clock source for MCG module is the slow internal clock source 32.768kHz
Core clock = 41.94MHz, BusClock = 41.94MHz
1 ... Multipurpose Clock Generator (MCG) in PLL Engaged External (PEE) mode
Reference clock source for MCG module is an external crystal 8MHz
Core clock = 48MHz, BusClock = 48MHz
2 ... Multipurpose Clock Generator (MCG) in Bypassed Low Power External (BLPE) mode
Core clock/Bus clock derived directly from an external crystal 8MHz with no multiplication
Core clock = 8MHz, BusClock = 8MHz
*/
/*----------------------------------------------------------------------------
Define clock source values
*----------------------------------------------------------------------------*/
#if (CLOCK_SETUP == 0)
#define CPU_XTAL_CLK_HZ 8000000u /* Value of the external crystal or oscillator clock frequency in Hz */
#define CPU_XTAL32k_CLK_HZ 32768u /* Value of the external 32k crystal or oscillator clock frequency in Hz */
#define CPU_INT_SLOW_CLK_HZ 32768u /* Value of the slow internal oscillator clock frequency in Hz */
#define CPU_INT_FAST_CLK_HZ 4000000u /* Value of the fast internal oscillator clock frequency in Hz */
#define DEFAULT_SYSTEM_CLOCK 41943040u /* Default System clock value */
#elif (CLOCK_SETUP == 1)
#define CPU_XTAL_CLK_HZ 8000000u /* Value of the external crystal or oscillator clock frequency in Hz */
#define CPU_XTAL32k_CLK_HZ 32768u /* Value of the external 32k crystal or oscillator clock frequency in Hz */
#define CPU_INT_SLOW_CLK_HZ 32768u /* Value of the slow internal oscillator clock frequency in Hz */
#define CPU_INT_FAST_CLK_HZ 4000000u /* Value of the fast internal oscillator clock frequency in Hz */
#define DEFAULT_SYSTEM_CLOCK 48000000u /* Default System clock value */
#elif (CLOCK_SETUP == 2)
#define CPU_XTAL_CLK_HZ 8000000u /* Value of the external crystal or oscillator clock frequency in Hz */
#define CPU_XTAL32k_CLK_HZ 32768u /* Value of the external 32k crystal or oscillator clock frequency in Hz */
#define CPU_INT_SLOW_CLK_HZ 32768u /* Value of the slow internal oscillator clock frequency in Hz */
#define CPU_INT_FAST_CLK_HZ 4000000u /* Value of the fast internal oscillator clock frequency in Hz */
#define DEFAULT_SYSTEM_CLOCK 8000000u /* Default System clock value */
#elif (CLOCK_SETUP == 3)
/* for Infinity */
#define CPU_XTAL_CLK_HZ 8000000u
#define CPU_XTAL32k_CLK_HZ 32768u
#define CPU_INT_SLOW_CLK_HZ 32768u
#define CPU_INT_FAST_CLK_HZ 4000000u
#define DEFAULT_SYSTEM_CLOCK 48000000u
#endif
/* ----------------------------------------------------------------------------
-- Core clock
---------------------------------------------------------------------------- */
uint32_t SystemCoreClock = DEFAULT_SYSTEM_CLOCK;
/* ----------------------------------------------------------------------------
-- SystemInit()
---------------------------------------------------------------------------- */
void SystemInit (void) {
#if (DISABLE_WDOG)
/* Disable the WDOG module */
/* WDOG_UNLOCK: WDOGUNLOCK=0xC520 */
WDOG->UNLOCK = (uint16_t)0xC520u; /* Key 1 */
/* WDOG_UNLOCK : WDOGUNLOCK=0xD928 */
WDOG->UNLOCK = (uint16_t)0xD928u; /* Key 2 */
/* WDOG_STCTRLH: ??=0,DISTESTWDOG=0,BYTESEL=0,TESTSEL=0,TESTWDOG=0,??=0,STNDBYEN=1,WAITEN=1,STOPEN=1,DBGEN=0,ALLOWUPDATE=1,WINEN=0,IRQRSTEN=0,CLKSRC=1,WDOGEN=0 */
WDOG->STCTRLH = (uint16_t)0x01D2u;
#endif /* (DISABLE_WDOG) */
#if (CLOCK_SETUP == 0)
/* SIM->CLKDIV1: OUTDIV1=0,OUTDIV2=0,OUTDIV3=1,OUTDIV4=1,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
SIM->CLKDIV1 = (uint32_t)0x00110000u; /* Update system prescalers */
/* Switch to FEI Mode */
/* MCG->C1: CLKS=0,FRDIV=0,IREFS=1,IRCLKEN=1,IREFSTEN=0 */
MCG->C1 = (uint8_t)0x06u;
/* MCG->C2: ??=0,??=0,RANGE0=0,HGO=0,EREFS=0,LP=0,IRCS=0 */
MCG->C2 = (uint8_t)0x00u;
/* MCG_C4: DMX32=0,DRST_DRS=1 */
MCG->C4 = (uint8_t)((MCG->C4 & (uint8_t)~(uint8_t)0xC0u) | (uint8_t)0x20u);
/* MCG->C5: ??=0,PLLCLKEN=0,PLLSTEN=0,PRDIV0=0 */
MCG->C5 = (uint8_t)0x00u;
/* MCG->C6: LOLIE=0,PLLS=0,CME=0,VDIV0=0 */
MCG->C6 = (uint8_t)0x00u;
while((MCG->S & MCG_S_IREFST_MASK) == 0u) { /* Check that the source of the FLL reference clock is the internal reference clock. */
}
while((MCG->S & 0x0Cu) != 0x00u) { /* Wait until output of the FLL is selected */
}
#elif (CLOCK_SETUP == 1)
/* SIM->CLKDIV1: OUTDIV1=0,OUTDIV2=0,OUTDIV3=1,OUTDIV4=1,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
SIM->CLKDIV1 = (uint32_t)0x00110000u; /* Update system prescalers */
/* Switch to FBE Mode */
/* OSC0->CR: ERCLKEN=0,??=0,EREFSTEN=0,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC0->CR = (uint8_t)0x00u;
/* MCG->C7: OSCSEL=0 */
MCG->C7 = (uint8_t)0x00u;
/* MCG->C2: ??=0,??=0,RANGE0=2,HGO=0,EREFS=1,LP=0,IRCS=0 */
MCG->C2 = (uint8_t)0x24u;
/* MCG->C1: CLKS=2,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
MCG->C1 = (uint8_t)0x9Au;
/* MCG->C4: DMX32=0,DRST_DRS=0 */
MCG->C4 &= (uint8_t)~(uint8_t)0xE0u;
/* MCG->C5: ??=0,PLLCLKEN=0,PLLSTEN=0,PRDIV0=3 */
MCG->C5 = (uint8_t)0x03u;
/* MCG->C6: LOLIE=0,PLLS=0,CME=0,VDIV0=0 */
MCG->C6 = (uint8_t)0x00u;
while((MCG->S & MCG_S_OSCINIT0_MASK) == 0u) { /* Check that the oscillator is running */
}
#if 0 /* ARM: THIS CHECK IS REMOVED DUE TO BUG WITH SLOW IRC IN REV. 1.0 */
while((MCG->S & MCG_S_IREFST_MASK) != 0u) { /* Check that the source of the FLL reference clock is the external reference clock. */
}
#endif
while((MCG->S & 0x0Cu) != 0x08u) { /* Wait until external reference clock is selected as MCG output */
}
/* Switch to PBE Mode */
/* MCG_C5: ??=0,PLLCLKEN=0,PLLSTEN=0,PRDIV0=3 */
MCG->C5 = (uint8_t)0x03u;
/* MCG->C6: LOLIE=0,PLLS=1,CME=0,VDIV0=0 */
MCG->C6 = (uint8_t)0x40u;
while((MCG->S & MCG_S_PLLST_MASK) == 0u) { /* Wait until the source of the PLLS clock has switched to the PLL */
}
while((MCG->S & MCG_S_LOCK0_MASK) == 0u) { /* Wait until locked */
}
/* Switch to PEE Mode */
/* MCG->C1: CLKS=0,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
MCG->C1 = (uint8_t)0x1Au;
while((MCG->S & 0x0Cu) != 0x0Cu) { /* Wait until output of the PLL is selected */
}
while((MCG->S & MCG_S_LOCK0_MASK) == 0u) { /* Wait until locked */
}
#elif (CLOCK_SETUP == 2)
/* SIM_CLKDIV1: OUTDIV1=0,OUTDIV2=0,OUTDIV3=1,OUTDIV4=1,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
SIM->CLKDIV1 = (uint32_t)0x00110000u; /* Update system prescalers */
/* Switch to FBE Mode */
/* OSC0->CR: ERCLKEN=0,??=0,EREFSTEN=0,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC0->CR = (uint8_t)0x00u;
/* MCG->C7: OSCSEL=0 */
MCG->C7 = (uint8_t)0x00u;
/* MCG->C2: ??=0,??=0,RANGE0=2,HGO=0,EREFS=1,LP=0,IRCS=0 */
MCG->C2 = (uint8_t)0x24u;
/* MCG->C1: CLKS=2,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
MCG->C1 = (uint8_t)0x9Au;
/* MCG->C4: DMX32=0,DRST_DRS=0 */
MCG->C4 &= (uint8_t)~(uint8_t)0xE0u;
/* MCG->C5: ??=0,PLLCLKEN=0,PLLSTEN=0,PRDIV0=0 */
MCG->C5 = (uint8_t)0x00u;
/* MCG->C6: LOLIE=0,PLLS=0,CME=0,VDIV0=0 */
MCG->C6 = (uint8_t)0x00u;
while((MCG->S & MCG_S_OSCINIT0_MASK) == 0u) { /* Check that the oscillator is running */
}
#if 0 /* ARM: THIS CHECK IS REMOVED DUE TO BUG WITH SLOW IRC IN REV. 1.0 */
while((MCG->S & MCG_S_IREFST_MASK) != 0u) { /* Check that the source of the FLL reference clock is the external reference clock. */
}
#endif
while((MCG->S & 0x0CU) != 0x08u) { /* Wait until external reference clock is selected as MCG output */
}
/* Switch to BLPE Mode */
/* MCG->C2: ??=0,??=0,RANGE0=2,HGO=0,EREFS=1,LP=0,IRCS=0 */
MCG->C2 = (uint8_t)0x24u;
#elif (CLOCK_SETUP == 3)
/* for Infinity FEI: 48MHz */
/* OUTDIV1(core/system): 48/1, OUTDIV2(bus): 48/1, OUTDIV4(flash): 48/2 */
SIM->CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0) | SIM_CLKDIV1_OUTDIV2(0) | SIM_CLKDIV1_OUTDIV4(1);
MCG->C1 = MCG_C1_IREFS_MASK | MCG_C1_IRCLKEN_MASK;
/* 32.768KHz x FLL(1464) = 48MHz */
MCG->C4 = MCG_C4_DMX32_MASK | MCG_C4_DRST_DRS(1);
/* USB clock source: MCGPLLCLK/MCGFLLCLK */
//SIM->SOPT2 = SIM_SOPT2_USBSRC_MASK | SIM_SOPT2_TRACECLKSEL_MASK;
while((MCG->S & MCG_S_IREFST_MASK) == 0u) { }
while((MCG->S & 0x0Cu) != 0x00u) { }
#endif
}
/* ----------------------------------------------------------------------------
-- SystemCoreClockUpdate()
---------------------------------------------------------------------------- */
void SystemCoreClockUpdate (void) {
uint32_t MCGOUTClock; /* Variable to store output clock frequency of the MCG module */
uint8_t Divider;
if ((MCG->C1 & MCG_C1_CLKS_MASK) == 0x0u) {
/* Output of FLL or PLL is selected */
if ((MCG->C6 & MCG_C6_PLLS_MASK) == 0x0u) {
/* FLL is selected */
if ((MCG->C1 & MCG_C1_IREFS_MASK) == 0x0u) {
/* External reference clock is selected */
if ((MCG->C7 & MCG_C7_OSCSEL_MASK) == 0x0u) {
MCGOUTClock = CPU_XTAL_CLK_HZ; /* System oscillator drives MCG clock */
} else { /* (!((MCG->C7 & MCG_C7_OSCSEL_MASK) == 0x0u)) */
MCGOUTClock = CPU_XTAL32k_CLK_HZ; /* RTC 32 kHz oscillator drives MCG clock */
} /* (!((MCG->C7 & MCG_C7_OSCSEL_MASK) == 0x0u)) */
Divider = (uint8_t)(1u << ((MCG->C1 & MCG_C1_FRDIV_MASK) >> MCG_C1_FRDIV_SHIFT));
MCGOUTClock = (MCGOUTClock / Divider); /* Calculate the divided FLL reference clock */
if ((MCG->C2 & MCG_C2_RANGE0_MASK) != 0x0u) {
MCGOUTClock /= 32u; /* If high range is enabled, additional 32 divider is active */
} /* ((MCG->C2 & MCG_C2_RANGE0_MASK) != 0x0u) */
} else { /* (!((MCG->C1 & MCG_C1_IREFS_MASK) == 0x0u)) */
MCGOUTClock = CPU_INT_SLOW_CLK_HZ; /* The slow internal reference clock is selected */
} /* (!((MCG->C1 & MCG_C1_IREFS_MASK) == 0x0u)) */
/* Select correct multiplier to calculate the MCG output clock */
switch (MCG->C4 & (MCG_C4_DMX32_MASK | MCG_C4_DRST_DRS_MASK)) {
case 0x0u:
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) == 0x0u)) */
/* PLL is selected */
Divider = (1u + (MCG->C5 & MCG_C5_PRDIV0_MASK));
MCGOUTClock = (uint32_t)(CPU_XTAL_CLK_HZ / Divider); /* Calculate the PLL reference clock */
Divider = ((MCG->C6 & MCG_C6_VDIV0_MASK) + 24u);
MCGOUTClock *= Divider; /* Calculate the MCG output clock */
} /* (!((MCG->C6 & MCG_C6_PLLS_MASK) == 0x0u)) */
} else if ((MCG->C1 & MCG_C1_CLKS_MASK) == 0x40u) {
/* Internal reference clock is selected */
if ((MCG->C2 & MCG_C2_IRCS_MASK) == 0x0u) {
MCGOUTClock = CPU_INT_SLOW_CLK_HZ; /* Slow internal reference clock selected */
} else { /* (!((MCG->C2 & MCG_C2_IRCS_MASK) == 0x0u)) */
MCGOUTClock = CPU_INT_FAST_CLK_HZ / (1 << ((MCG->SC & MCG_SC_FCRDIV_MASK) >> MCG_SC_FCRDIV_SHIFT)); /* Fast internal reference clock selected */
} /* (!((MCG->C2 & MCG_C2_IRCS_MASK) == 0x0u)) */
} else if ((MCG->C1 & MCG_C1_CLKS_MASK) == 0x80u) {
/* External reference clock is selected */
if ((MCG->C7 & MCG_C7_OSCSEL_MASK) == 0x0u) {
MCGOUTClock = CPU_XTAL_CLK_HZ; /* System oscillator drives MCG clock */
} else { /* (!((MCG->C7 & MCG_C7_OSCSEL_MASK) == 0x0u)) */
MCGOUTClock = CPU_XTAL32k_CLK_HZ; /* RTC 32 kHz oscillator drives MCG clock */
} /* (!((MCG->C7 & MCG_C7_OSCSEL_MASK) == 0x0u)) */
} else { /* (!((MCG->C1 & MCG_C1_CLKS_MASK) == 0x80u)) */
/* Reserved value */
return;
} /* (!((MCG->C1 & MCG_C1_CLKS_MASK) == 0x80u)) */
SystemCoreClock = (MCGOUTClock / (1u + ((SIM->CLKDIV1 & SIM_CLKDIV1_OUTDIV1_MASK) >> SIM_CLKDIV1_OUTDIV1_SHIFT)));
}
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