+++ /dev/null
-/*
-** ###################################################################
-** Compilers: ARM Compiler
-** Freescale C/C++ for Embedded ARM
-** GNU C Compiler
-** IAR ANSI C/C++ Compiler for ARM
-**
-**
-**
-** 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: 2015 Freescale Semiconductor, Inc. All Rights Reserved.
-**
-** http: www.freescale.com
-** mail: support@freescale.com
-**
-** Revisions:
-** - rev. 1.0 (2011-12-15)
-** Initial version
-**
-** ###################################################################
-*/
-
-/**
- * @file MK20DX256
- * @version 1.0
- * @date 2011-12-15
- * @brief Device specific configuration file for MK20DX256 (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 "MK20DX256.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
- This works on Teensy3.1
- 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
- 3 ... Multipurpose Clock Generator (MCG) in PLL Engaged External (PEE) mode
- Reference clock source for MCG module is an external crystal 16MHz
- Core clock = 72MHz, BusClock = 48MHz
- This is the default Teensy3.1 72Mhz set up
-*/
-
-/*----------------------------------------------------------------------------
- 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)
- #define CPU_XTAL_CLK_HZ 16000000u /* 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 72000000u /* Default System clock value */
-#endif /* (CLOCK_SETUP == 2) */
-
-
-/* ----------------------------------------------------------------------------
- -- Core clock
- ---------------------------------------------------------------------------- */
-
-uint32_t SystemCoreClock = DEFAULT_SYSTEM_CLOCK;
-
-/* ----------------------------------------------------------------------------
- -- SystemInit()
- ---------------------------------------------------------------------------- */
-void SystemInit (void) {
- /* SystemInit MUST NOT use any variables from the .data section, as this section is not loaded yet! */
-
-#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: DISTESTWDOG=0,BYTESEL=0,TESTSEL=0,TESTWDOG=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,OUTDIV4=1 Set Prescalers 41.94MHz cpu, 41.94MHz system, 20.97MHz flash*/
- SIM->CLKDIV1 = SIM_CLKDIV1_OUTDIV4(1);
- /* Switch to FEI Mode */
- /* MCG->C1: CLKS=0,FRDIV=0,IREFS=1,IRCLKEN=1,IREFSTEN=0 */
- MCG->C1 = MCG_C1_IREFS_MASK | MCG_C1_IRCLKEN_MASK;
- /* MCG->C2: LOCKRE0=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: 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,OUTDIV4=1 Set Prescalers 48MHz cpu, 48MHz system, 24MHz flash*/
- SIM->CLKDIV1 = SIM_CLKDIV1_OUTDIV4(1);
- /* Switch to FBE Mode */
- /* OSC0->CR: ERCLKEN=0,EREFSTEN=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: LOCKRE0=0,RANGE0=2,HGO=0,EREFS=1,LP=0,IRCS=0 */
- MCG->C2 = MCG_C2_RANGE0(2);
- /* MCG->C1: CLKS=2,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
- MCG->C1 = MCG_C1_CLKS(2) | MCG_C1_FRDIV(3) | MCG_C1_IRCLKEN_MASK;
- /* MCG->C4: DMX32=0,DRST_DRS=0 */
- MCG->C4 &= (uint8_t)~(uint8_t)0xE0u;
- /* MCG->C5: PLLCLKEN=0,PLLSTEN=0,PRDIV0=3 */
- MCG->C5 = MCG_C5_PRDIV0(3);
- /* 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 */
- while((MCG->S & 0x0Cu) != 0x08u) { } /* Wait until external reference clock is selected as MCG output */
- /* Switch to PBE Mode */
- /* MCG_C5: PLLCLKEN=0,PLLSTEN=0,PRDIV0=3 */
- MCG->C5 = MCG_C5_PRDIV0(3);
- /* MCG->C6: LOLIE=0,PLLS=1,CME=0,VDIV0=0 */
- MCG->C6 = MCG_C6_PLLS_MASK;
- 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 = MCG_C1_FRDIV(3) | MCG_C1_IRCLKEN_MASK;
- 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,OUTDIV4=1 Set Prescalers 8MHz cpu, 8MHz system, 8MHz flash*/
- SIM->CLKDIV1 = SIM_CLKDIV1_OUTDIV4(1);
- /* Switch to FBE Mode */
- /* OSC0->CR: ERCLKEN=0,EREFSTEN=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: LOCKRE0=0,RANGE0=2,HGO=0,EREFS=1,LP=0,IRCS=0 */
- MCG->C2 = MCG_C2_RANGE0(2) | MCG_C2_EREFS0_MASK;
- /* MCG->C1: CLKS=2,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
- MCG->C1 = MCG_C1_CLKS(2) | MCG_C1_FRDIV(3) | MCG_C1_IRCLKEN_MASK;
- /* MCG->C4: DMX32=0,DRST_DRS=0 */
- MCG->C4 &= (uint8_t)~(uint8_t)0xE0u;
- /* MCG->C5: 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 */
- while((MCG->S & 0x0CU) != 0x08u) { } /* Wait until external reference clock is selected as MCG output */
- /* Switch to BLPE Mode */
- /* MCG->C2: LOCKRE0=0,RANGE0=2,HGO=0,EREFS=1,LP=0,IRCS=0 */
- MCG->C2 = MCG_C2_RANGE0(2) | MCG_C2_EREFS0_MASK;
-
-#elif (CLOCK_SETUP == 3)
- /* SIM->CLKDIV1: OUTDIV1=0,OUTDIV2=0,OUTDIV4=1 Set Prescalers 72MHz cpu, 72MHz system, 36MHz flash*/
- SIM->CLKDIV1 = SIM_CLKDIV1_OUTDIV4(1);
- /* SIM->CLKDIV2: USBDIV=2,USBFRAC=1 Divide 72MHz system clock for USB 48MHz */
- SIM->CLKDIV2 = SIM_CLKDIV2_USBDIV(2) | SIM_CLKDIV2_USBFRAC_MASK;
- /* OSC0->CR: ERCLKEN=0,EREFSTEN=0,SC2P=1,SC4P=0,SC8P=1,SC16P=0 10pF loading capacitors for 16MHz system oscillator*/
- OSC0->CR = OSC_CR_SC8P_MASK | OSC_CR_SC2P_MASK;
- /* Switch to FBE Mode */
- /* MCG->C7: OSCSEL=0 */
- MCG->C7 = (uint8_t)0x00u;
- /* MCG->C2: LOCKRE0=0,RANGE0=2,HGO=0,EREFS=1,LP=0,IRCS=0 */
- MCG->C2 = MCG_C2_RANGE0(2) | MCG_C2_EREFS0_MASK;
- //MCG->C2 = (uint8_t)0x24u;
- /* MCG->C1: CLKS=2,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
- MCG->C1 = MCG_C1_CLKS(2) | MCG_C1_FRDIV(3) | MCG_C1_IRCLKEN_MASK;
- /* MCG->C4: DMX32=0,DRST_DRS=0,FCTRIM=0,SCFTRIM=0 */
- MCG->C4 &= (uint8_t)~(uint8_t)0xE0u;
- /* MCG->C5: PLLCLKEN=0,PLLSTEN=0,PRDIV0=7 */
- MCG->C5 = MCG_C5_PRDIV0(7);
- /* 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 */
- while((MCG->S & 0x0Cu) != 0x08u) { } /* Wait until external reference clock is selected as MCG output */
- /* Switch to PBE Mode */
- /* MCG_C5: PLLCLKEN=0,PLLSTEN=0,PRDIV0=5 */
- MCG->C5 = MCG_C5_PRDIV0(5);
- /* MCG->C6: LOLIE=0,PLLS=1,CME=0,VDIV0=3 */
- MCG->C6 = MCG_C6_PLLS_MASK | MCG_C6_VDIV0(3);
- 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=2,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
- MCG->C1 = MCG_C1_FRDIV(2) | MCG_C1_IRCLKEN_MASK;
- while((MCG->S & 0x0Cu) != 0x0Cu) { } /* Wait until output of the PLL is selected */
- while((MCG->S & MCG_S_LOCK0_MASK) == 0u) { } /* Wait until locked */
-#endif /* (CLOCK_SETUP) */
-}
-
-/* ----------------------------------------------------------------------------
- -- 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)));
-}