/*
** ===================================================================
** Method : Cpu_SetMCGModeFBE (component MK21FN1M0MC12)
**
** Description :
** This method sets the MCG to FBE mode.
** This method is internal. It is used by Processor Expert only.
** ===================================================================
*/
static void Cpu_SetMCGModeFBE(uint8_t CLKMode)
{
switch (CLKMode) {
case 0U:
/* Switch to FBE Mode */
/* MCG_C2: LOCRE0=0,??=0,RANGE0=2,HGO0=0,EREFS0=1,LP=0,IRCS=0 */
MCG_C2 = (MCG_C2_RANGE0(0x02) | MCG_C2_EREFS0_MASK);
/* OSC_CR: ERCLKEN=1,??=0,EREFSTEN=1,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC_CR = (OSC_CR_ERCLKEN_MASK | OSC_CR_EREFSTEN_MASK);
/* MCG_C7: OSCSEL=0 */
MCG_C7 &= (uint8_t)~(uint8_t)(MCG_C7_OSCSEL_MASK);
/* MCG_C1: CLKS=2,FRDIV=3,IREFS=0,IRCLKEN=0,IREFSTEN=0 */
MCG_C1 = (MCG_C1_CLKS(0x02) | MCG_C1_FRDIV(0x03));
/* MCG_C4: DMX32=0,DRST_DRS=0 */
MCG_C4 &= (uint8_t)~(uint8_t)((MCG_C4_DMX32_MASK | MCG_C4_DRST_DRS(0x03)));
/* MCG_C5: ??=0,PLLCLKEN0=0,PLLSTEN0=0,PRDIV0=1 */
MCG_C5 = MCG_C5_PRDIV0(0x01);
/* MCG_C6: LOLIE0=0,PLLS=0,CME0=0,VDIV0=6 */
MCG_C6 = MCG_C6_VDIV0(0x06);
while((MCG_S & MCG_S_OSCINIT0_MASK) == 0x00U) { /* Check that the oscillator is running */
}
while((MCG_S & MCG_S_IREFST_MASK) != 0x00U) { /* Check that the source of the FLL reference clock is the external reference clock. */
}
while((MCG_S & 0x0CU) != 0x08U) { /* Wait until external reference clock is selected as MCG output */
}
break;
case 1U:
/* Switch to FBE Mode */
/* MCG_C2: LOCRE0=0,??=0,RANGE0=2,HGO0=0,EREFS0=1,LP=0,IRCS=1 */
MCG_C2 = (MCG_C2_RANGE0(0x02) | MCG_C2_EREFS0_MASK | MCG_C2_IRCS_MASK);
/* OSC_CR: ERCLKEN=1,??=0,EREFSTEN=0,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC_CR = OSC_CR_ERCLKEN_MASK;
/* MCG_C7: OSCSEL=0 */
MCG_C7 &= (uint8_t)~(uint8_t)(MCG_C7_OSCSEL_MASK);
/* MCG_C1: CLKS=2,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
MCG_C1 = (MCG_C1_CLKS(0x02) | MCG_C1_FRDIV(0x03) | MCG_C1_IRCLKEN_MASK);
/* MCG_C4: DMX32=0,DRST_DRS=0 */
MCG_C4 &= (uint8_t)~(uint8_t)((MCG_C4_DMX32_MASK | MCG_C4_DRST_DRS(0x03)));
/* MCG_C5: ??=0,PLLCLKEN0=0,PLLSTEN0=0,PRDIV0=0 */
MCG_C5 = MCG_C5_PRDIV0(0x00);
/* MCG_C6: LOLIE0=0,PLLS=0,CME0=0,VDIV0=0 */
MCG_C6 = MCG_C6_VDIV0(0x00);
while((MCG_S & MCG_S_OSCINIT0_MASK) == 0x00U) { /* Check that the oscillator is running */
}
while((MCG_S & MCG_S_IREFST_MASK) != 0x00U) { /* Check that the source of the FLL reference clock is the external reference clock. */
}
while((MCG_S & 0x0CU) != 0x08U) { /* Wait until external reference clock is selected as MCG output */
}
break;
default:
break;
}
}
void BoardConfig_vfnInit(void)
{
/* SIM_SOPT2: PLLFLLSEL=1 */
SIM_SOPT2 |= SIM_SOPT2_PLLFLLSEL_MASK; /* Select PLL as a clock source for various peripherals */
/* SIM_SOPT1: OSC32KSEL=3 */
SIM_SOPT1 |= SIM_SOPT1_OSC32KSEL(0x03); /* LPO 1kHz oscillator drives 32 kHz clock for various peripherals */
/* Switch to FBE Mode */
/* MCG_C2: LOCRE0=0,??=0,RANGE0=2,HGO0=0,EREFS0=1,LP=0,IRCS=0 */
MCG_C2 = (MCG_C2_RANGE0(0x02) | MCG_C2_EREFS0_MASK);
/* OSC0_CR: ERCLKEN=1,??=0,EREFSTEN=0,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC0_CR = OSC_CR_ERCLKEN_MASK;
/* MCG_C1: CLKS=2,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
MCG_C1 = (MCG_C1_CLKS(0x02) | MCG_C1_FRDIV(0x03) | MCG_C1_IRCLKEN_MASK);
/* MCG_C4: DMX32=0,DRST_DRS=0 */
MCG_C4 &= (uint8_t)~(uint8_t)((MCG_C4_DMX32_MASK | MCG_C4_DRST_DRS(0x03)));
/* MCG_C5: ??=0,PLLCLKEN0=0,PLLSTEN0=0,PRDIV0=3 */
MCG_C5 = MCG_C5_PRDIV0(0x03);
/* MCG_C6: LOLIE0=0,PLLS=0,CME0=0,VDIV0=0 */
MCG_C6 = MCG_C6_VDIV0(0x00);
while((MCG_S & MCG_S_IREFST_MASK) != 0x00U) { /* Check that the source of the FLL reference clock is the external reference clock. */
}
while((MCG_S & 0x0CU) != 0x08U) { /* Wait until external reference clock is selected as MCG output */
}
/* Switch to PBE Mode */
/* MCG_C6: LOLIE0=0,PLLS=1,CME0=0,VDIV0=0 */
MCG_C6 = (MCG_C6_PLLS_MASK | MCG_C6_VDIV0(0x00));
while((MCG_S & 0x0CU) != 0x08U) { /* Wait until external reference clock is selected as MCG output */
}
while((MCG_S & MCG_S_LOCK0_MASK) == 0x00U) { /* Wait until locked */
}
SIM_SCGC5 |= SIM_SCGC5_PORTB_MASK | SIM_SCGC5_PORTC_MASK | SIM_SCGC5_PORTD_MASK;
GPIO_vfnPinMux(GPIO_PORT_C,10,GPIO_MUX_ALT_1);
GPIO_vfnPinMux(GPIO_PORT_C,11,GPIO_MUX_ALT_1);
GPIO_vfnPinMux(GPIO_PORT_C,12,GPIO_MUX_ALT_1);
GPIO_vfnPinMux(GPIO_PORT_C,13,GPIO_MUX_ALT_1);
GPIO_vfnPinMux(GPIO_PORT_D,7,GPIO_MUX_ALT_1);
GPIO_vfnPinMux(GPIO_PORT_D,6,GPIO_MUX_ALT_1);
GPIO_vfnPinMux(GPIO_PORT_B,19,GPIO_MUX_ALT_1);
GPIOC_PDDR |= (1<<10) | (1<<11) | (1<<12) | (1<<13);
GPIOD_PDDR |= (1<<7) | (1<<6);
GPIOB_PDDR |= (1<<19);
}
/**
**===========================================================================
** Reset handler
**===========================================================================
*/
void __init_hardware(void) {
/* This is a cleaned up output of Processor Expert generated code */
/* Set the interrupt vector table position */
SCB_VTOR = (uint32_t)__vector_table;
#if 0
/* Disable the WDOG module */
SIM_COPC = SIM_COPC_COPT(0x00);
#endif
/* System clock initialization */
/* Enable clock gate for ports to enable pin routing */
SIM_SCGC5 |= SIM_SCGC5_PORTA_MASK;
/* Update system prescalers */
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0x00) | SIM_CLKDIV1_OUTDIV4(0x01);
/* Select FLL as a clock source for various peripherals */
SIM_SOPT2 &= ~SIM_SOPT2_PLLFLLSEL_MASK;
/* LPO 1kHz oscillator drives 32 kHz clock for various peripherals */
SIM_SOPT1 |= SIM_SOPT1_OSC32KSEL(0x03);
/* Set the TPM clock */
SIM_SOPT2 &= ~SIM_SOPT2_TPMSRC(0x01);
SIM_SOPT2 |= SIM_SOPT2_TPMSRC(0x02);
/* Enable XTAL IO pins */
PORTA_PCR18 = PORT_PCR_MUX(0);
PORTA_PCR19 = PORT_PCR_MUX(0);
/* Switch to FBE Mode */
MCG_C2 = MCG_C2_RANGE0(0x02) | MCG_C2_EREFS0_MASK;
OSC0_CR = OSC_CR_ERCLKEN_MASK;
MCG_C1 = MCG_C1_CLKS(0x02) | MCG_C1_FRDIV(0x03) | MCG_C1_IRCLKEN_MASK;
MCG_C4 &= ~MCG_C4_DMX32_MASK | MCG_C4_DRST_DRS(0x03);
MCG_C5 = MCG_C5_PRDIV0(0x03);
MCG_C6 = MCG_C6_VDIV0(0x00);
/* Check that the source of the FLL reference clock is the external reference clock. */
while((MCG_S & MCG_S_IREFST_MASK) != 0x00U);
/* Wait until external reference clock is selected as MCG output */
while((MCG_S & 0x0CU) != 0x08U);
/* Switch to PBE Mode */
MCG_C6 = (MCG_C6_PLLS_MASK | MCG_C6_VDIV0(0x00));
/* Wait until external reference clock is selected as MCG output */
while((MCG_S & 0x0CU) != 0x08U);
/* Wait until locked */
while((MCG_S & MCG_S_LOCK0_MASK) == 0x00U);
/* Switch to PEE Mode */
MCG_C1 = MCG_C1_CLKS(0x00) | MCG_C1_FRDIV(0x03) | MCG_C1_IRCLKEN_MASK;
/* Wait until output of the PLL is selected */
while((MCG_S & 0x0CU) != 0x0CU);
}
void PEE(void)
{
MCG->C6 &= ~MCG_C6_CME0_MASK;
MCG->C2 &= ~MCG_C2_LP_MASK;
MCG->C2 |= MCG_C2_RANGE0(3) |// Very high frequency range selected for the crystal oscillator
MCG_C2_EREFS0_MASK ;
MCG->C5 &= ~MCG_C5_PRDIV0_MASK;
MCG->C5 |= MCG_C5_PRDIV0(2 - 1); // External clock div 4
MCG->C6 &= ~MCG_C6_VDIV0_MASK;
MCG->C6 |= MCG_C6_VDIV0(24 - 24) | // Mul 24. 8 / 4 * 24 = 48MHz
MCG_C6_CME0_MASK |
MCG_C6_PLLS_MASK;
MCG->C1 &= ~MCG_C1_CLKS_MASK;
MCG->C1 |= ~MCG_C1_CLKS_MASK | // Output of PLL is selected for MCGOUTCLK
MCG_C1_FRDIV(3) |
MCG_C1_IRCLKEN_MASK;
while((MCG->S & MCG_S_OSCINIT0_MASK) == 0); // wait for osc init.
while((MCG->S & MCG_S_PLLST_MASK) != MCG_S_PLLST_MASK); // wait for PLL
while((MCG->S & MCG_S_CLKST_MASK) != MCG_S_CLKST(3)); // wait for PLL is selected
SIM->CLKDIV1 = SIM_CLKDIV1_OUTDIV1(2 - 1) | // core/system clock = MCGOUTCLK / 2 = 96 / 2 = 48MHz
SIM_CLKDIV1_OUTDIV4(2 - 1); // flash/bus clock = core/system / 2 = 24MHz
}
/*lint -esym(765,Cpu_Interrupt) Disable MISRA rule (8.10) checking for symbols (Cpu_Interrupt). */
void __init_hardware(void)
{
/*** !!! Here you can place your own code before PE initialization using property "User code before PE initialization" on the build options tab. !!! ***/
/*** ### MKL25Z128VLK4 "Cpu" init code ... ***/
/*** PE initialization code after reset ***/
SCB_VTOR = (uint32_t)(&__vect_table); /* Set the interrupt vector table position */
/* Disable the WDOG module */
/* SIM_COPC: ??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,COPT=0,COPCLKS=0,COPW=0 */
SIM_COPC = SIM_COPC_COPT(0x00);
/* System clock initialization */
/* SIM_CLKDIV1: OUTDIV1=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,OUTDIV4=3,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
SIM_CLKDIV1 = (SIM_CLKDIV1_OUTDIV1(0x00) | SIM_CLKDIV1_OUTDIV4(0x03)); /* Set the system prescalers to safe value */
/* SIM_SCGC5: PORTD=1,PORTB=1,PORTA=1 */
SIM_SCGC5 |= SIM_SCGC5_PORTD_MASK |
SIM_SCGC5_PORTB_MASK |
SIM_SCGC5_PORTA_MASK; /* Enable clock gate for ports to enable pin routing */
if ((PMC_REGSC & PMC_REGSC_ACKISO_MASK) != 0x0U) {
/* PMC_REGSC: ACKISO=1 */
PMC_REGSC |= PMC_REGSC_ACKISO_MASK; /* Release IO pads after wakeup from VLLS mode. */
}
/* SIM_CLKDIV1: OUTDIV1=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,OUTDIV4=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
SIM_CLKDIV1 = (SIM_CLKDIV1_OUTDIV1(0x00) | SIM_CLKDIV1_OUTDIV4(0x00)); /* Update system prescalers */
/* SIM_SOPT2: PLLFLLSEL=0 */
SIM_SOPT2 &= (uint32_t)~(uint32_t)(SIM_SOPT2_PLLFLLSEL_MASK); /* Select FLL as a clock source for various peripherals */
/* SIM_SOPT1: OSC32KSEL=3 */
SIM_SOPT1 |= SIM_SOPT1_OSC32KSEL(0x03); /* LPO 1kHz oscillator drives 32 kHz clock for various peripherals */
/* SIM_SOPT2: TPMSRC=1 */
SIM_SOPT2 = (uint32_t)((SIM_SOPT2 & (uint32_t)~(uint32_t)(
SIM_SOPT2_TPMSRC(0x02)
)) | (uint32_t)(
SIM_SOPT2_TPMSRC(0x01)
)); /* Set the TPM clock */
/* Switch to FEI Mode */
/* MCG_C1: CLKS=0,FRDIV=0,IREFS=1,IRCLKEN=1,IREFSTEN=0 */
MCG_C1 = MCG_C1_CLKS(0x00) |
MCG_C1_FRDIV(0x00) |
MCG_C1_IREFS_MASK |
MCG_C1_IRCLKEN_MASK;
/* MCG_C2: LOCRE0=0,??=0,RANGE0=0,HGO0=0,EREFS0=0,LP=0,IRCS=0 */
MCG_C2 = MCG_C2_RANGE0(0x00);
/* MCG_C4: DMX32=0,DRST_DRS=0 */
MCG_C4 &= (uint8_t)~(uint8_t)((MCG_C4_DMX32_MASK | MCG_C4_DRST_DRS(0x03)));
/* OSC0_CR: ERCLKEN=1,??=0,EREFSTEN=0,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC0_CR = OSC_CR_ERCLKEN_MASK;
/* MCG_C5: ??=0,PLLCLKEN0=0,PLLSTEN0=0,PRDIV0=0 */
MCG_C5 = MCG_C5_PRDIV0(0x00);
/* MCG_C6: LOLIE0=0,PLLS=0,CME0=0,VDIV0=0 */
MCG_C6 = MCG_C6_VDIV0(0x00);
while((MCG_S & MCG_S_IREFST_MASK) == 0x00U) { /* 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 */
}
/*** End of PE initialization code after reset ***/
/*** !!! Here you can place your own code after PE initialization using property "User code after PE initialization" on the build options tab. !!! ***/
}
/**
* @brief Initialize the PLL Bypassed External Mode.
*
* MCGOUTCLK is derived from external reference clock (oscillator).
* PLL output is not used.
* Clock source is the external reference clock (oscillator).
* The PLL loop will locks to VDIV times the frequency
* corresponding by PRDIV.
* Previous allowed mode are FBE or BLPE.
*/
static void kinetis_mcg_set_pbe(void)
{
/* select external reference clock and divide factor */
MCG->C1 = (uint8_t)(MCG_C1_CLKS(2) | MCG_C1_FRDIV(KINETIS_MCG_ERC_FRDIV));
/* Wait until ERC is selected */
while ((MCG->S & MCG_S_CLKST_MASK) != MCG_S_CLKST(2));
/* PLL is not disabled in bypass mode */
MCG->C2 &= ~(uint8_t)(MCG_C2_LP_MASK);
/* set external reference devider */
MCG->C5 = (uint8_t)(MCG_C5_PRDIV0(KINETIS_MCG_PLL_PRDIV));
/* set external reference devider */
MCG->C6 = (uint8_t)(MCG_C6_VDIV0(KINETIS_MCG_PLL_VDIV0));
/* select PLL */
MCG->C6 |= (uint8_t)(MCG_C6_PLLS_MASK);
/* Wait until the source of the PLLS clock is PLL */
while ((MCG->S & MCG_S_PLLST_MASK) == 0);
/* Wait until PLL locked */
while ((MCG->S & MCG_S_LOCK0_MASK) == 0);
current_mode = KINETIS_MCG_PBE;
}
/*
** ===================================================================
** Method : Cpu_SetMCGModePBE (component MK22FN512VDC12)
**
** Description :
** This method sets the MCG to PBE mode.
** This method is internal. It is used by Processor Expert only.
** ===================================================================
*/
static void Cpu_SetMCGModePBE(uint8_t CLKMode)
{
switch (CLKMode) {
case 0U:
/* Switch to PBE Mode */
/* OSC_CR: ERCLKEN=1,??=0,EREFSTEN=1,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC_CR = (OSC_CR_ERCLKEN_MASK | OSC_CR_EREFSTEN_MASK);
/* MCG_C7: OSCSEL=0 */
MCG_C7 &= (uint8_t)~(uint8_t)(MCG_C7_OSCSEL_MASK);
/* MCG_C1: CLKS=2,FRDIV=3,IREFS=0,IRCLKEN=0,IREFSTEN=0 */
MCG_C1 = (MCG_C1_CLKS(0x02) | MCG_C1_FRDIV(0x03));
/* MCG_C2: LOCRE0=0,??=0,RANGE0=2,HGO0=0,EREFS0=1,LP=0,IRCS=0 */
MCG_C2 = (MCG_C2_RANGE(0x02) | MCG_C2_EREFS_MASK);
/* MCG_C5: ??=0,PLLCLKEN0=0,PLLSTEN0=0,PRDIV0=b (devider is 12) */
MCG_C5 = MCG_C5_PRDIV0(0x0b);
/* MCG_C6: LOLIE0=0,PLLS=1,CME0=0,VDIV0=0x10 (multiply is 40)*/
MCG_C6 = (MCG_C6_PLLS_MASK | MCG_C6_VDIV0(0x10));
while((MCG_S & 0x0CU) != 0x08U) { /* Wait until external reference clock is selected as MCG output */
}
while((MCG_S & MCG_S_LOCK0_MASK) == 0x00U) { /* Wait until locked */
}
break;
case 1U:
/* Switch to PBE Mode */
/* OSC_CR: ERCLKEN=1,??=0,EREFSTEN=0,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC_CR = OSC_CR_ERCLKEN_MASK;
/* MCG_C7: OSCSEL=0 */
MCG_C7 &= (uint8_t)~(uint8_t)(MCG_C7_OSCSEL_MASK);
/* MCG_C1: CLKS=2,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
MCG_C1 = (MCG_C1_CLKS(0x02) | MCG_C1_FRDIV(0x03) | MCG_C1_IRCLKEN_MASK);
/* MCG_C2: LOCRE0=0,??=0,RANGE0=2,HGO0=0,EREFS0=1,LP=0,IRCS=1 */
MCG_C2 = (MCG_C2_RANGE(0x02) | MCG_C2_EREFS_MASK | MCG_C2_IRCS_MASK);
/* MCG_C5: ??=0,PLLCLKEN0=0,PLLSTEN0=0,PRDIV0=b(devider is 12) */
MCG_C5 = MCG_C5_PRDIV0(0x0b);
/* MCG_C6: LOLIE0=0,PLLS=1,CME0=0,VDIV0=0x10 (multiply is 40)*/
MCG_C6 = (MCG_C6_PLLS_MASK | MCG_C6_VDIV0(0x10));
/* FCTRIM = 13*/
while((MCG_S & 0x0CU) != 0x08U) { /* Wait until external reference clock is selected as MCG output */
}
while((MCG_S & MCG_S_LOCK0_MASK) == 0x00U) { /* Wait until locked */
}
break;
default:
break;
}
}
/*****************************************************************************
* @name pll_init
*
* @brief: Initialization of the MCU.
*
* @param : None
*
* @return : None
*****************************************************************************
* It will configure the MCU to disable STOP and COP Modules.
* It also set the MCG configuration and bus clock frequency.
****************************************************************************/
static unsigned char pll_init()
{
/* First move to FBE mode */
/* Enable external oscillator, RANGE=1, HGO=1, EREFS=1, LP=0, IRCS=0 */
MCG_C2 = MCG_C2_RANGE0(2) | MCG_C2_HGO0_MASK | MCG_C2_EREFS0_MASK | MCG_C2_IRCS_MASK;
/* Select external oscillator and Reference Divider and clear IREFS to start ext osc
CLKS=2, FRDIV=3, IREFS=0, IRCLKEN=0, IREFSTEN=0 */
MCG_C1 = MCG_C1_CLKS(2) | MCG_C1_FRDIV(3);
/* Wait for oscillator to initialize */
while (!(MCG_S & MCG_S_OSCINIT0_MASK)){};
/* Wait for Reference clock Status bit to clear */
while (MCG_S & MCG_S_IREFST_MASK){};
/* Wait for clock status bits to show clock source is ext ref clk */
while (((MCG_S & MCG_S_CLKST_MASK) >> MCG_S_CLKST_SHIFT) != 0x2){};
MCG_C5 = MCG_C5_PRDIV0(BSP_REF_CLOCK_DIV - 1) | MCG_C5_PLLCLKEN0_MASK;
/* Ensure MCG_C6 is at the reset default of 0. LOLIE disabled,
PLL enabled, clk monitor disabled, PLL VCO divider is clear */
MCG_C6 = 0;
/* Set system options dividers */
#if (defined MCU_MK20D5) || (defined MCU_MK40D7)
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(BSP_CORE_DIV - 1) | /* core/system clock */
SIM_CLKDIV1_OUTDIV2(BSP_BUS_DIV - 1) | /* peripheral clock; */
SIM_CLKDIV1_OUTDIV4(BSP_FLASH_DIV - 1); /* flash clock */
#else
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(BSP_CORE_DIV - 1) | /* Core/system clock */
SIM_CLKDIV1_OUTDIV2(BSP_BUS_DIV - 1) | /* Peripheral clock; */
SIM_CLKDIV1_OUTDIV3(BSP_FLEXBUS_DIV - 1)| /* FlexBus clock driven to the external pin (FB_CLK)*/
SIM_CLKDIV1_OUTDIV4(BSP_FLASH_DIV - 1); /* Flash clock */
#endif
/* Set the VCO divider and enable the PLL, LOLIE = 0, PLLS = 1, CME = 0, VDIV = */
MCG_C6 = MCG_C6_PLLS_MASK | MCG_C6_VDIV0(BSP_CLOCK_MUL - 24); /* 2MHz * BSP_CLOCK_MUL */
while (!(MCG_S & MCG_S_PLLST_MASK)){}; /* Wait for PLL status bit to set */
while (!(MCG_S & MCG_S_LOCK0_MASK)){}; /* Wait for LOCK bit to set */
/* Transition into PEE by setting CLKS to 0
CLKS=0, FRDIV=3, IREFS=0, IRCLKEN=0, IREFSTEN=0 */
MCG_C1 &= ~MCG_C1_CLKS_MASK;
/* Wait for clock status bits to update */
while (((MCG_S & MCG_S_CLKST_MASK) >> MCG_S_CLKST_SHIFT) != 0x3){};
/* Enable the ER clock of oscillators */
OSC_CR = OSC_CR_ERCLKEN_MASK | OSC_CR_EREFSTEN_MASK;
/* Now running in PEE Mode */
SIM_SOPT1 |= SIM_SOPT1_USBREGEN_MASK;
return 0;
} //pll_init
/*
** ===================================================================
** Method : Cpu_SetMCGClockInModePEE (component MK22FN512VDC12)
**
** Description :
** Calling of this method will cause the clock frequency
** change in mode PEE, typically from 120M to 80M, vice versa.
** Parameters :
** NAME - DESCRIPTION
** ModeID - Clock configuration identifier
** Returns :
** --- - ERR_OK - OK.
** ERR_RANGE - Mode parameter out of range
** ===================================================================
*/
static LDD_TError Cpu_SetMCGClockInModePEE(LDD_TClockConfiguration ModeID)
{
if (ModeID > 0x03U)
return ERR_RANGE;
switch (ModeID) {
case CPU_CLOCK_CONFIG_3:
/* OSC_CR: ERCLKEN=1,??=0,EREFSTEN=0,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC_CR = OSC_CR_ERCLKEN_MASK;
/* SIM_SOPT2: MCGCLKSEL=0 */
SIM_SOPT2 |= SIM_SOPT2_PLLFLLSEL(0x01);
/* MCG_C1: CLKS=0,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
MCG_C1 = (MCG_C1_FRDIV(0x03) | MCG_C1_IRCLKEN_MASK);
/* MCG_C2: ??=0,??=0,RANGE=2,HGO=0,EREFS=1,LP=0,IRCS=0 */
MCG_C2 = (MCG_C2_RANGE(0x02) | MCG_C2_EREFS_MASK);
/* MCG_C5: ??=0,PLLCLKEN=0,PLLSTEN=0,PRDIV=5 (devider is 6) */
MCG_C5 = MCG_C5_PRDIV0(0x05);
/* MCG_C6: LOLIE=0,PLLS=1,CME=0,VDIV=6 */
MCG_C6 = (MCG_C6_PLLS_MASK | MCG_C6_VDIV0(0x06));
while((MCG_S & 0x0CU) != 0x0CU) { /* Wait until output of the PLL is selected */
}
break;
case CPU_CLOCK_CONFIG_0:
/* OSC_CR: ERCLKEN=1,??=0,EREFSTEN=0,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC_CR = (uint8_t)0x80U;
/* SIM_SOPT2: MCGCLKSEL=0 */
SIM_SOPT2 |= SIM_SOPT2_PLLFLLSEL(0x01);
/* MCG_C1: CLKS=0,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
MCG_C1 = (MCG_C1_FRDIV(0x03) | MCG_C1_IRCLKEN_MASK);
/* MCG_C2: ??=0,??=0,RANGE=2,HGO=0,EREFS=1,LP=0,IRCS=0 */
MCG_C2 = (MCG_C2_RANGE(0x02) | MCG_C2_EREFS_MASK);
/* MCG_C5: ??=0,PLLCLKEN=0,PLLSTEN=0,PRDIV=0xb (devider is 12) */
MCG_C5 = MCG_C5_PRDIV0(0x0b);
/* MCG_C6: LOLIE=0,PLLS=1,CME=0,VDIV=16 (multiply is 40)*/
MCG_C6 = (MCG_C6_PLLS_MASK | MCG_C6_VDIV0(0x10));
while((MCG_S & 0x0CU) != 0x0CU) { /* Wait until output of the PLL is selected */
}
break;
default:
break;
}
return ERR_OK;
}
void FBE_to_PBE (void )
{
MCG->C5 |=MCG_C5_PRDIV0(0x3); // Divider Factor = 4 , 8MHz/4=2MHz in range 2MHz->4MHz
MCG->C6 |=MCG_C6_PLLS_MASK ; // PLL is selected
MCG->C6 |=MCG_C6_VDIV0(0x18); // PLL out = 2MHz * 48 = 96MHz
while((MCG->S & 0x0CU) != 0x08U) { /* Wait until external reference clock is selected as MCG output */
}
while((MCG->S & MCG_S_LOCK0_MASK) == 0x00U) { /* Wait until locked */
}
}
void Clock_init(void)
{
// Init system clock
/* System clock initialization */
/* SIM_SCGC5: PORTA=1 */
SIM_SCGC5 |= SIM_SCGC5_PORTA_MASK; /* Enable clock gate for ports to enable pin routing */
/* SIM_CLKDIV1: OUTDIV1=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,OUTDIV4=1,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
SIM_CLKDIV1 = (SIM_CLKDIV1_OUTDIV1(0x00) | SIM_CLKDIV1_OUTDIV4(0x01)); /* Update system prescalers */
/* SIM_SOPT2: PLLFLLSEL=0 */
SIM_SOPT2 &= (uint32_t)~(uint32_t)(SIM_SOPT2_PLLFLLSEL_MASK); /* Select FLL as a clock source for various peripherals */
/* SIM_SOPT1: OSC32KSEL=0 */
SIM_SOPT1 &= (uint32_t)~(uint32_t)(SIM_SOPT1_OSC32KSEL(0x03)); /* System oscillator drives 32 kHz clock for various peripherals */
/* SIM_SOPT2: TPMSRC=1 */
SIM_SOPT2 = (uint32_t)((SIM_SOPT2 & (uint32_t)~(uint32_t)(
SIM_SOPT2_TPMSRC(0x02)
)) | (uint32_t)(
SIM_SOPT2_TPMSRC(0x01)
)); /* Set the TPM clock */
/* PORTA_PCR18: ISF=0,MUX=0 */
PORTA_PCR18 &= (uint32_t)~(uint32_t)((PORT_PCR_ISF_MASK | PORT_PCR_MUX(0x07)));
/* PORTA_PCR19: ISF=0,MUX=0 */
PORTA_PCR19 &= (uint32_t)~(uint32_t)((PORT_PCR_ISF_MASK | PORT_PCR_MUX(0x07)));
/* MCG_SC: FCRDIV=1 */
MCG_SC = (uint8_t)((MCG_SC & (uint8_t)~(uint8_t)(
MCG_SC_FCRDIV(0x06)
)) | (uint8_t)(
MCG_SC_FCRDIV(0x01)
));
/* Switch to FEE Mode */
/* MCG_C2: LOCRE0=0,??=0,RANGE0=2,HGO0=0,EREFS0=1,LP=0,IRCS=1 */
MCG_C2 = (MCG_C2_RANGE0(0x02) | MCG_C2_EREFS0_MASK | MCG_C2_IRCS_MASK);
/* OSC0_CR: ERCLKEN=1,??=0,EREFSTEN=0,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC0_CR = OSC_CR_ERCLKEN_MASK;
/* MCG_C1: CLKS=0,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
MCG_C1 = (MCG_C1_CLKS(0x00) | MCG_C1_FRDIV(0x03) | MCG_C1_IRCLKEN_MASK);
/* MCG_C4: DMX32=0,DRST_DRS=1 */
MCG_C4 = (uint8_t)((MCG_C4 & (uint8_t)~(uint8_t)(
MCG_C4_DMX32_MASK |
MCG_C4_DRST_DRS(0x02)
)) | (uint8_t)(
MCG_C4_DRST_DRS(0x01)
));
/* MCG_C5: ??=0,PLLCLKEN0=0,PLLSTEN0=0,PRDIV0=0 */
MCG_C5 = MCG_C5_PRDIV0(0x00);
/* MCG_C6: LOLIE0=0,PLLS=0,CME0=0,VDIV0=0 */
MCG_C6 = MCG_C6_VDIV0(0x00);
while((MCG_S & MCG_S_IREFST_MASK) != 0x00U) { /* Check that the source of the FLL reference clock is the external reference clock. */
}
while((MCG_S & 0x0CU) != 0x00U) { /* Wait until output of the FLL is selected */
}
/*** End of PE initialization code after reset ***/
}
void CLOCK_EnablePll0(mcg_pll_config_t const *config)
{
assert(config);
uint8_t mcg_c5 = 0U;
mcg_c5 |= MCG_C5_PRDIV0(config->prdiv);
MCG->C5 = mcg_c5; /* Disable the PLL first. */
MCG->C6 = (MCG->C6 & ~MCG_C6_VDIV0_MASK) | MCG_C6_VDIV0(config->vdiv);
/* Set enable mode. */
MCG->C5 |= ((uint32_t)kMCG_PllEnableIndependent | (uint32_t)config->enableMode);
/* Wait for PLL lock. */
while (!(MCG->S & MCG_S_LOCK0_MASK))
{
}
}
/* Switch to PBE Mode */
void PBE(void)
{
MCG->C6 &= ~MCG_C6_CME0_MASK;
MCG->C2 &= ~MCG_C2_LP_MASK;
MCG->C2 |= MCG_C2_RANGE0(3) |// Very high frequency range selected for the crystal oscillator
MCG_C2_EREFS0_MASK;
MCG->C5 &= ~MCG_C5_PRDIV0_MASK;
MCG->C5 |= MCG_C5_PRDIV0(2 - 1); // External clock div 2
MCG->C6 &= ~MCG_C6_VDIV0_MASK;
MCG->C6 |= MCG_C6_VDIV0(24 - 24) | // Mul 24. 8 / 2 * 24 = 96MHz
MCG_C6_CME0_MASK |
MCG_C6_PLLS_MASK;
MCG->C1 &= ~MCG_C1_CLKS_MASK;
MCG->C1 |= MCG_C1_CLKS(2); // Output of ExTAL is selected for MCGOUTCLK
while((MCG->S & MCG_S_OSCINIT0_MASK) == 0); // wait for osc init.
while((MCG->S & MCG_S_PLLST_MASK) != MCG_S_PLLST_MASK); // wait for PLL
while((MCG->S & MCG_S_CLKST_MASK) != MCG_S_CLKST(2)); // wait for EXTAL is selected
}
/*
** ===================================================================
** Method : Cpu_SetMCGModePEE (component MK21FN1M0MC12)
**
** Description :
** This method sets the MCG to PEE mode.
** This method is internal. It is used by Processor Expert only.
** ===================================================================
*/
static void Cpu_SetMCGModePEE(uint8_t CLKMode)
{
switch (CLKMode) {
case 0U:
/* Switch to PEE Mode */
/* OSC_CR: ERCLKEN=1,??=0,EREFSTEN=1,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC_CR = (OSC_CR_ERCLKEN_MASK | OSC_CR_EREFSTEN_MASK);
/* MCG_C7: OSCSEL=0 */
MCG_C7 &= (uint8_t)~(uint8_t)(MCG_C7_OSCSEL_MASK);
/* MCG_C1: CLKS=0,FRDIV=3,IREFS=0,IRCLKEN=0,IREFSTEN=0 */
MCG_C1 = (MCG_C1_CLKS(0x00) | MCG_C1_FRDIV(0x03));
/* MCG_C2: LOCRE0=0,??=0,RANGE0=2,HGO0=0,EREFS0=1,LP=0,IRCS=0 */
MCG_C2 = (MCG_C2_RANGE0(0x02) | MCG_C2_EREFS0_MASK);
/* MCG_C5: ??=0,PLLCLKEN0=0,PLLSTEN0=0,PRDIV0=1 */
MCG_C5 = MCG_C5_PRDIV0(0x01);
/* MCG_C6: LOLIE0=0,PLLS=1,CME0=0,VDIV0=6 */
MCG_C6 = (MCG_C6_PLLS_MASK | MCG_C6_VDIV0(0x06));
while((MCG_S & 0x0CU) != 0x0CU) { /* Wait until output of the PLL is selected */
}
break;
default:
break;
}
}
/*lint -esym(765,Cpu_Interrupt) Disable MISRA rule (8.10) checking for symbols (Cpu_Interrupt). */
void __init_hardware(void)
{
/*** !!! Here you can place your own code before PE initialization using property "User code before PE initialization" on the build options tab. !!! ***/
/*** ### MK70FN1M0VMJ12 "Cpu" init code ... ***/
/*** PE initialization code after reset ***/
SCB_VTOR = (uint32_t)(&__vect_table); /* Set the interrupt vector table position */
/* Disable the WDOG module */
/* 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;
/* System clock initialization */
/* SIM_CLKDIV1: OUTDIV1=0,OUTDIV2=1,OUTDIV3=3,OUTDIV4=3,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0x00) |
SIM_CLKDIV1_OUTDIV2(0x01) |
SIM_CLKDIV1_OUTDIV3(0x03) |
SIM_CLKDIV1_OUTDIV4(0x03); /* Set the system prescalers to safe value */
/* SIM_SCGC5: PORTE=1,PORTA=1 */
SIM_SCGC5 |= (SIM_SCGC5_PORTE_MASK | SIM_SCGC5_PORTA_MASK); /* Enable clock gate for ports to enable pin routing */
if ((PMC_REGSC & PMC_REGSC_ACKISO_MASK) != 0x0U) {
/* PMC_REGSC: ACKISO=1 */
PMC_REGSC |= PMC_REGSC_ACKISO_MASK; /* Release IO pads after wakeup from VLLS mode. */
}
/* 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 = SIM_CLKDIV1_OUTDIV1(0x00) |
SIM_CLKDIV1_OUTDIV2(0x00) |
SIM_CLKDIV1_OUTDIV3(0x01) |
SIM_CLKDIV1_OUTDIV4(0x01); /* Update system prescalers */
/* SIM_SOPT2: PLLFLLSEL=0 */
SIM_SOPT2 &= (uint32_t)~(uint32_t)(SIM_SOPT2_PLLFLLSEL(0x03)); /* Select FLL as a clock source for various peripherals */
/* SIM_SOPT1: OSC32KSEL=0 */
SIM_SOPT1 &= (uint32_t)~(uint32_t)(SIM_SOPT1_OSC32KSEL_MASK); /* System oscillator drives 32 kHz clock for various peripherals */
/* SIM_SCGC1: OSC1=1 */
SIM_SCGC1 |= SIM_SCGC1_OSC1_MASK;
/* Switch to FEI Mode */
/* MCG_C1: CLKS=0,FRDIV=0,IREFS=1,IRCLKEN=1,IREFSTEN=0 */
MCG_C1 = MCG_C1_CLKS(0x00) |
MCG_C1_FRDIV(0x00) |
MCG_C1_IREFS_MASK |
MCG_C1_IRCLKEN_MASK;
/* MCG_C2: LOCRE0=0,??=0,RANGE0=0,HGO0=0,EREFS0=0,LP=0,IRCS=0 */
MCG_C2 = MCG_C2_RANGE0(0x00);
/* MCG_C4: DMX32=0,DRST_DRS=0 */
MCG_C4 &= (uint8_t)~(uint8_t)((MCG_C4_DMX32_MASK | MCG_C4_DRST_DRS(0x03)));
/* OSC0_CR: ERCLKEN=1,??=0,EREFSTEN=0,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC0_CR = OSC_CR_ERCLKEN_MASK;
/* MCG_C10: LOCRE2=0,??=0,RANGE1=0,HGO1=0,EREFS1=0,??=0,??=0 */
MCG_C10 = MCG_C10_RANGE1(0x00);
/* OSC1_CR: ERCLKEN=1,??=0,EREFSTEN=0,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC1_CR = OSC_CR_ERCLKEN_MASK;
/* MCG_C7: OSCSEL=0 */
MCG_C7 &= (uint8_t)~(uint8_t)(MCG_C7_OSCSEL_MASK);
/* MCG_C5: PLLREFSEL0=0,PLLCLKEN0=0,PLLSTEN0=0,??=0,??=0,PRDIV0=0 */
MCG_C5 = MCG_C5_PRDIV0(0x00);
/* MCG_C6: LOLIE0=0,PLLS=0,CME0=0,VDIV0=0 */
MCG_C6 = MCG_C6_VDIV0(0x00);
/* MCG_C11: PLLREFSEL1=0,PLLCLKEN1=0,PLLSTEN1=0,PLLCS=0,??=0,PRDIV1=0 */
MCG_C11 = MCG_C11_PRDIV1(0x00);
/* MCG_C12: LOLIE1=0,??=0,CME2=0,VDIV1=0 */
MCG_C12 = MCG_C12_VDIV1(0x00); /* 3 */
while((MCG_S & MCG_S_IREFST_MASK) == 0x00U) { /* 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 */
}
/*** End of PE initialization code after reset ***/
/*** !!! Here you can place your own code after PE initialization using property "User code after PE initialization" on the build options tab. !!! ***/
}
/*lint -esym(765,Cpu_Interrupt) Disable MISRA rule (8.10) checking for symbols (Cpu_Interrupt). */
void __init_hardware(void)
{
/*** !!! Here you can place your own code before PE initialization using property "User code before PE initialization" on the build options tab. !!! ***/
/*** ### MKL46Z256VMC4 "Cpu" init code ... ***/
/*** PE initialization code after reset ***/
SCB_VTOR = (uint32_t)(&__vect_table); /* Set the interrupt vector table position */
/* Disable the WDOG module */
/* SIM_COPC: ??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,COPT=0,COPCLKS=0,COPW=0 */
SIM_COPC = SIM_COPC_COPT(0x00);
/* System clock initialization */
/* SIM_SCGC5: PORTE=1,PORTC=1,PORTB=1,PORTA=1 */
SIM_SCGC5 |= SIM_SCGC5_PORTE_MASK |
SIM_SCGC5_PORTC_MASK |
SIM_SCGC5_PORTB_MASK |
SIM_SCGC5_PORTA_MASK; /* Enable clock gate for ports to enable pin routing */
/* SIM_CLKDIV1: OUTDIV1=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,OUTDIV4=1,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
SIM_CLKDIV1 = (SIM_CLKDIV1_OUTDIV1(0x00) | SIM_CLKDIV1_OUTDIV4(0x01)); /* Update system prescalers */
/* SIM_SOPT2: PLLFLLSEL=1 */
SIM_SOPT2 |= SIM_SOPT2_PLLFLLSEL_MASK; /* Select PLL as a clock source for various peripherals */
/* SIM_SOPT1: OSC32KSEL=2 */
SIM_SOPT1 = (uint32_t)((SIM_SOPT1 & (uint32_t)~(uint32_t)(
SIM_SOPT1_OSC32KSEL(0x01)
)) | (uint32_t)(
SIM_SOPT1_OSC32KSEL(0x02)
)); /* System oscillator drives 32 kHz clock for various peripherals */
/* SIM_SOPT2: TPMSRC=1 */
SIM_SOPT2 = (uint32_t)((SIM_SOPT2 & (uint32_t)~(uint32_t)(
SIM_SOPT2_TPMSRC(0x02)
)) | (uint32_t)(
SIM_SOPT2_TPMSRC(0x01)
)); /* Set the TPM clock */
/* PORTA_PCR18: ISF=0,MUX=0 */
PORTA_PCR18 &= (uint32_t)~(uint32_t)((PORT_PCR_ISF_MASK | PORT_PCR_MUX(0x07)));
/* PORTA_PCR19: ISF=0,MUX=0 */
PORTA_PCR19 &= (uint32_t)~(uint32_t)((PORT_PCR_ISF_MASK | PORT_PCR_MUX(0x07)));
/* Switch to FBE Mode */
/* MCG_C2: LOCRE0=0,RANGE0=2,HGO0=0,EREFS0=1,LP=0,IRCS=0 */
MCG_C2 = (uint8_t)((MCG_C2 & (uint8_t)~(uint8_t)(
MCG_C2_LOCRE0_MASK |
MCG_C2_RANGE0(0x01) |
MCG_C2_HGO0_MASK |
MCG_C2_LP_MASK |
MCG_C2_IRCS_MASK
)) | (uint8_t)(
MCG_C2_RANGE0(0x02) |
MCG_C2_EREFS0_MASK
));
/* OSC0_CR: ERCLKEN=1,??=0,EREFSTEN=0,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC0_CR = OSC_CR_ERCLKEN_MASK;
/* MCG_C1: CLKS=2,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
MCG_C1 = (MCG_C1_CLKS(0x02) | MCG_C1_FRDIV(0x03) | MCG_C1_IRCLKEN_MASK);
/* MCG_C4: DMX32=0,DRST_DRS=0 */
MCG_C4 &= (uint8_t)~(uint8_t)((MCG_C4_DMX32_MASK | MCG_C4_DRST_DRS(0x03)));
/* MCG_C5: ??=0,PLLCLKEN0=0,PLLSTEN0=0,PRDIV0=3 */
MCG_C5 = MCG_C5_PRDIV0(0x03);
/* MCG_C6: LOLIE0=0,PLLS=0,CME0=0,VDIV0=0 */
MCG_C6 = MCG_C6_VDIV0(0x00);
while((MCG_S & MCG_S_IREFST_MASK) != 0x00U) { /* Check that the source of the FLL reference clock is the external reference clock. */
}
while((MCG_S & 0x0CU) != 0x08U) { /* Wait until external reference clock is selected as MCG output */
}
/* Switch to PBE Mode */
/* MCG_C6: LOLIE0=0,PLLS=1,CME0=0,VDIV0=0 */
MCG_C6 = (MCG_C6_PLLS_MASK | MCG_C6_VDIV0(0x00));
while((MCG_S & 0x0CU) != 0x08U) { /* Wait until external reference clock is selected as MCG output */
}
while((MCG_S & MCG_S_LOCK0_MASK) == 0x00U) { /* Wait until locked */
}
/* Switch to PEE Mode */
/* MCG_C1: CLKS=0,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
MCG_C1 = (MCG_C1_CLKS(0x00) | MCG_C1_FRDIV(0x03) | MCG_C1_IRCLKEN_MASK);
while((MCG_S & 0x0CU) != 0x0CU) { /* Wait until output of the PLL is selected */
}
/* Initialization of the RTC_CLKIN pin */
/* PORTC_PCR1: ISF=0,MUX=1 */
PORTC_PCR1 = (uint32_t)((PORTC_PCR1 & (uint32_t)~(uint32_t)(
PORT_PCR_ISF_MASK |
PORT_PCR_MUX(0x06)
)) | (uint32_t)(
PORT_PCR_MUX(0x01)
));
/*** End of PE initialization code after reset ***/
/*** !!! Here you can place your own code after PE initialization using property "User code after PE initialization" on the build options tab. !!! ***/
}
void ResetHandler(void)
{
uint32_t *src = &_etext;
uint32_t *dest = &_sdata;
WDOG_UNLOCK = WDOG_UNLOCK_SEQ1;
WDOG_UNLOCK = WDOG_UNLOCK_SEQ2;
WDOG_STCTRLH = WDOG_STCTRLH_ALLOWUPDATE;
startup_early_hook();
// enable clocks to always-used peripherals
SIM_SCGC5 = 0x00043F82; // clocks active to all GPIO
SIM_SCGC6 = SIM_SCGC6_RTC | SIM_SCGC6_FTM0 | SIM_SCGC6_FTM1 | SIM_SCGC6_ADC0 | SIM_SCGC6_FTFL;
// if the RTC oscillator isn't enabled, get it started early
if (!(RTC_CR & RTC_CR_OSCE)) {
RTC_SR = 0;
RTC_CR = RTC_CR_SC16P | RTC_CR_SC4P | RTC_CR_OSCE;
}
// TODO: do this while the PLL is waiting to lock....
while (dest < &_edata) *dest++ = *src++;
dest = &_sbss;
while (dest < &_ebss) *dest++ = 0;
SCB_VTOR = 0; // use vector table in flash
// start in FEI mode
// enable capacitors for crystal
OSC0_CR = OSC_SC8P | OSC_SC2P;
// enable osc, 8-32 MHz range, low power mode
MCG_C2 = MCG_C2_RANGE0(2) | MCG_C2_EREFS;
// switch to crystal as clock source, FLL input = 16 MHz / 512
MCG_C1 = MCG_C1_CLKS(2) | MCG_C1_FRDIV(4);
// wait for crystal oscillator to begin
while ((MCG_S & MCG_S_OSCINIT0) == 0) ;
// wait for FLL to use oscillator
while ((MCG_S & MCG_S_IREFST) != 0) ;
// wait for MCGOUT to use oscillator
while ((MCG_S & MCG_S_CLKST_MASK) != MCG_S_CLKST(2)) ;
// now we're in FBE mode
// config PLL input for 16 MHz Crystal / 4 = 4 MHz
MCG_C5 = MCG_C5_PRDIV0(3);
// config PLL for 96 MHz output
MCG_C6 = MCG_C6_PLLS | MCG_C6_VDIV0(0);
// wait for PLL to start using xtal as its input
while (!(MCG_S & MCG_S_PLLST)) ;
// wait for PLL to lock
while (!(MCG_S & MCG_S_LOCK0)) ;
// now we're in PBE mode
#if F_CPU == 96000000
// config divisors: 96 MHz core, 48 MHz bus, 24 MHz flash
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0) | SIM_CLKDIV1_OUTDIV2(1) | SIM_CLKDIV1_OUTDIV4(3);
#elif F_CPU == 48000000
// config divisors: 48 MHz core, 48 MHz bus, 24 MHz flash
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(1) | SIM_CLKDIV1_OUTDIV2(1) | SIM_CLKDIV1_OUTDIV4(3);
#elif F_CPU == 24000000
// config divisors: 24 MHz core, 24 MHz bus, 24 MHz flash
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(3) | SIM_CLKDIV1_OUTDIV2(3) | SIM_CLKDIV1_OUTDIV4(3);
#else
#error "Error, F_CPU must be 96000000, 48000000, or 24000000"
#endif
// switch to PLL as clock source, FLL input = 16 MHz / 512
MCG_C1 = MCG_C1_CLKS(0) | MCG_C1_FRDIV(4);
// wait for PLL clock to be used
while ((MCG_S & MCG_S_CLKST_MASK) != MCG_S_CLKST(3)) ;
// now we're in PEE mode
// configure USB for 48 MHz clock
SIM_CLKDIV2 = SIM_CLKDIV2_USBDIV(1); // USB = 96 MHz PLL / 2
// USB uses PLL clock, trace is CPU clock, CLKOUT=OSCERCLK0
SIM_SOPT2 = SIM_SOPT2_USBSRC | SIM_SOPT2_PLLFLLSEL | SIM_SOPT2_TRACECLKSEL | SIM_SOPT2_CLKOUTSEL(6);
// initialize the SysTick counter
SYST_RVR = (F_CPU / 1000) - 1;
SYST_CSR = SYST_CSR_CLKSOURCE | SYST_CSR_TICKINT | SYST_CSR_ENABLE;
//init_pins();
__enable_irq();
_init_Teensyduino_internal_();
if (RTC_SR & RTC_SR_TIF) rtc_set(TIME_T);
__libc_init_array();
/*
for (ptr = &__init_array_start; ptr < &__init_array_end; ptr++) {
(*ptr)();
}
*/
startup_late_hook();
main();
while (1) ;
}
/*!
* @brief PLL超频
* @param PLL_e 频率设置参数
* @return 超频频率（MHz）
* @since v5.0
* @warning 此函数只能在 复位后没进行任何频率设置情况下调用，即MCG在FEI模式下才可调用
* Sample usage: uint8 clk = pll_init(PLL100); //超频
*/
uint8 pll_init(PLL_e pll)
{
mcg_div_count( pll);
SIM_SCGC5 |= SIM_SCGC5_PORTA_MASK; //PTA18 和 PTA19 用于 晶振
// set clock dividers to desired value
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(mcg_div.core_div) | SIM_CLKDIV1_OUTDIV4(mcg_div.bus_div);
//上电复位后，单片机会自动进入 FEI 模式，使用 内部参考时钟
//FEI -> FBE
OSC0_CR = ( 0
| OSC_CR_ERCLKEN_MASK //使能 外部参考时钟
//| OSC_CR_SC2P_MASK //配置电容
//| OSC_CR_SC4P_MASK //配置电容
//| OSC_CR_SC8P_MASK //配置电容
| OSC_CR_SC16P_MASK //配置电容
);
MCG_C2 = ( 0
| MCG_C2_RANGE0(2)
| MCG_C2_EREFS0_MASK
);
MCG_C1 = (0
| MCG_C1_CLKS(2)
| MCG_C1_FRDIV(7)
| MCG_C1_IRCLKEN_MASK
);
while (MCG_S & MCG_S_IREFST_MASK) {}; //等待FLL参考时钟 为 外部参考时钟（S[IREFST]=0，表示使用外部参考时钟，）
while ((MCG_S & MCG_S_CLKST_MASK) != MCG_S_CLKST(0x2)) {}; //等待选择外部参考时钟
//现在已经进入了 FBE模式
//FBE -> PBE
MCG_C5 = MCG_C5_PRDIV0(mcg_cfg[pll].prdiv); //分频， EXTAL_IN_MHz/( PRDIV+1)
MCG_C6 = MCG_C6_PLLS_MASK | MCG_C6_VDIV0(mcg_cfg[pll].vdiv) ; //倍频， EXTAL_IN_MHz/( PRDIV+1) * (VDIV+24)
while (!(MCG_S & MCG_S_PLLST_MASK)) {}; //等待时钟源选择PLL
while (!(MCG_S & MCG_S_LOCK0_MASK)) {}; //等待 PLL锁了（锁相环）
// 现在已经进入了 PBE 模式
// PBE -> PEE
//MCG_C1 &= ~MCG_C1_CLKS_MASK;
MCG_C1 = MCG_C1_IRCLKEN_MASK;
while (((MCG_S & MCG_S_CLKST_MASK) ) != MCG_S_CLKST(0x3)) {};//等待选择输出PLL
// 现在已经进入了 PEE 模式
SIM_SOPT2 |= (0 //选择 PLL时钟
| SIM_SOPT2_PLLFLLSEL_MASK
);
return mcg_cfg[pll].clk;
} //pll_init
void Boot_Init_Clock(void){
/* System clock initialization */
/* SIM_CLKDIV1: OUTDIV1=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,OUTDIV4=3,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
SIM_CLKDIV1 = (SIM_CLKDIV1_OUTDIV1(0x00) | SIM_CLKDIV1_OUTDIV4(0x03)); /* Set the system prescalers to safe value */
/* SIM_SCGC5: PORTA=1 */
SIM_SCGC5 |= SIM_SCGC5_PORTA_MASK; /* Enable clock gate for ports to enable pin routing */
if ((PMC_REGSC & PMC_REGSC_ACKISO_MASK) != 0x0U) {
/* PMC_REGSC: ACKISO=1 */
PMC_REGSC |= PMC_REGSC_ACKISO_MASK; /* Release IO pads after wakeup from VLLS mode. */
}
/* SIM_CLKDIV1: OUTDIV1=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,OUTDIV4=1,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
SIM_CLKDIV1 = (SIM_CLKDIV1_OUTDIV1(0x00) | SIM_CLKDIV1_OUTDIV4(0x01)); /* Update system prescalers */
/* SIM_SOPT2: PLLFLLSEL=1 */
SIM_SOPT2 |= SIM_SOPT2_PLLFLLSEL_MASK; /* Select PLL as a clock source for various peripherals */
/* SIM_SOPT1: OSC32KSEL=3 */
SIM_SOPT1 |= SIM_SOPT1_OSC32KSEL(0x03); /* LPO 1kHz oscillator drives 32 kHz clock for various peripherals */
/* SIM_SOPT2: TPMSRC=1 */
SIM_SOPT2 = (uint32_t)((SIM_SOPT2 & (uint32_t)~(uint32_t)(
SIM_SOPT2_TPMSRC(0x02)
)) | (uint32_t)(
SIM_SOPT2_TPMSRC(0x01)
)); /* Set the TPM clock */
/* PORTA_PCR18: ISF=0,MUX=0 */
PORTA_PCR18 &= (uint32_t)~(uint32_t)((PORT_PCR_ISF_MASK | PORT_PCR_MUX(0x07)));
/* PORTA_PCR19: ISF=0,MUX=0 */
PORTA_PCR19 &= (uint32_t)~(uint32_t)((PORT_PCR_ISF_MASK | PORT_PCR_MUX(0x07)));
/* Switch to FBE Mode */
/* MCG_C2: LOCRE0=0,RANGE0=2,HGO0=0,EREFS0=1,LP=0,IRCS=0 */
MCG_C2 = (uint8_t)((MCG_C2 & (uint8_t)~(uint8_t)(
MCG_C2_LOCRE0_MASK |
MCG_C2_RANGE0(0x01) |
MCG_C2_HGO0_MASK |
MCG_C2_LP_MASK |
MCG_C2_IRCS_MASK
)) | (uint8_t)(
MCG_C2_RANGE0(0x02) |
MCG_C2_EREFS0_MASK
));
/* OSC0_CR: ERCLKEN=1,??=0,EREFSTEN=0,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC0_CR = OSC_CR_ERCLKEN_MASK;
/* MCG_C1: CLKS=2,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
MCG_C1 = (MCG_C1_CLKS(0x02) | MCG_C1_FRDIV(0x03) | MCG_C1_IRCLKEN_MASK);
/* MCG_C4: DMX32=0,DRST_DRS=0 */
MCG_C4 &= (uint8_t)~(uint8_t)((MCG_C4_DMX32_MASK | MCG_C4_DRST_DRS(0x03)));
/* MCG_C5: ??=0,PLLCLKEN0=0,PLLSTEN0=0,PRDIV0=3 */
MCG_C5 = MCG_C5_PRDIV0(0x03);
/* MCG_C6: LOLIE0=0,PLLS=0,CME0=0,VDIV0=0 */
MCG_C6 = MCG_C6_VDIV0(0x00);
while((MCG_S & MCG_S_IREFST_MASK) != 0x00U) { /* Check that the source of the FLL reference clock is the external reference clock. */
}
while((MCG_S & 0x0CU) != 0x08U) { /* Wait until external reference clock is selected as MCG output */
}
/* Switch to PBE Mode */
/* MCG_C6: LOLIE0=0,PLLS=1,CME0=0,VDIV0=0 */
MCG_C6 = (MCG_C6_PLLS_MASK | MCG_C6_VDIV0(0x00));
while((MCG_S & 0x0CU) != 0x08U) { /* Wait until external reference clock is selected as MCG output */
}
while((MCG_S & MCG_S_LOCK0_MASK) == 0x00U) { /* Wait until locked */
}
/* Switch to PEE Mode */
/* MCG_C1: CLKS=0,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
MCG_C1 = (MCG_C1_CLKS(0x00) | MCG_C1_FRDIV(0x03) | MCG_C1_IRCLKEN_MASK);
while((MCG_S & 0x0CU) != 0x0CU) { /* Wait until output of the PLL is selected */
}
/* MCG_C6: CME0=1 */
MCG_C6 |= MCG_C6_CME0_MASK; /* Enable the clock monitor */
/*** End of PE initialization code after reset ***/
}
void ResetHandler(void)
{
/*
* Enable watchdog timer. Allow settings to be changed later, in case the
* application firmware wants to adjust its settings or disable it.
*
* Originally I tried using the 1 kHz low-power oscillator here, but that seemed to
* run into an issue where refreshes weren't taking effect. It seems similar to
* this problem on the Freescale forums, which didn't really have a satisfactory
* solution:
*
* https://community.freescale.com/thread/309519
*
* As a workaround, I'm using the "alternate" system clock.
*/
{
const uint32_t watchdog_timeout = F_BUS / 100; // 10ms
WDOG_UNLOCK = WDOG_UNLOCK_SEQ1;
WDOG_UNLOCK = WDOG_UNLOCK_SEQ2;
asm volatile ("nop");
asm volatile ("nop");
WDOG_STCTRLH = WDOG_STCTRLH_ALLOWUPDATE | WDOG_STCTRLH_WDOGEN |
WDOG_STCTRLH_WAITEN | WDOG_STCTRLH_STOPEN | WDOG_STCTRLH_CLKSRC;
WDOG_PRESC = 0;
WDOG_TOVALH = watchdog_timeout >> 16;
WDOG_TOVALL = watchdog_timeout;
}
// enable clocks to always-used peripherals
SIM_SCGC5 = 0x00043F82; // clocks active to all GPIO
SIM_SCGC6 = SIM_SCGC6_RTC | SIM_SCGC6_FTM0 | SIM_SCGC6_FTM1 | SIM_SCGC6_ADC0 | SIM_SCGC6_FTFL;
// release I/O pins hold, if we woke up from VLLS mode
if (PMC_REGSC & PMC_REGSC_ACKISO) PMC_REGSC |= PMC_REGSC_ACKISO;
// start in FEI mode
// enable capacitors for crystal
OSC0_CR = OSC_SC8P | OSC_SC2P;
// enable osc, 8-32 MHz range, low power mode
MCG_C2 = MCG_C2_RANGE0(2) | MCG_C2_EREFS;
// switch to crystal as clock source, FLL input = 16 MHz / 512
MCG_C1 = MCG_C1_CLKS(2) | MCG_C1_FRDIV(4);
// wait for crystal oscillator to begin
while ((MCG_S & MCG_S_OSCINIT0) == 0) ;
// wait for FLL to use oscillator
while ((MCG_S & MCG_S_IREFST) != 0) ;
// wait for MCGOUT to use oscillator
while ((MCG_S & MCG_S_CLKST_MASK) != MCG_S_CLKST(2)) ;
// now we're in FBE mode
// config PLL input for 16 MHz Crystal / 4 = 4 MHz
MCG_C5 = MCG_C5_PRDIV0(3);
// config PLL for 96 MHz output
MCG_C6 = MCG_C6_PLLS | MCG_C6_VDIV0(0);
// Copy things while we're waiting on the PLL
{
// Relocate data and text to RAM
uint32_t *src = &_eflash;
uint32_t *dest = &_sdtext;
while (dest < &_edtext) *dest++ = *src++;
// Clear BSS
dest = &_sbss;
while (dest < &_ebss) *dest++ = 0;
// Copy IVT to RAM
src = (uint32_t*) &gVectors[0];
dest = &ramVectors[0];
while (dest <= &ramVectors[63]) *dest++ = *src++;
// Switch to ram IVT
SCB_VTOR = (uint32_t) &ramVectors[0];
}
// wait for PLL to start using xtal as its input
while (!(MCG_S & MCG_S_PLLST)) ;
// wait for PLL to lock
while (!(MCG_S & MCG_S_LOCK0)) ;
// now we're in PBE mode
// config divisors: 48 MHz core, 48 MHz bus, 24 MHz flash
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(1) | SIM_CLKDIV1_OUTDIV2(1) | SIM_CLKDIV1_OUTDIV4(3);
// switch to PLL as clock source, FLL input = 16 MHz / 512
MCG_C1 = MCG_C1_CLKS(0) | MCG_C1_FRDIV(4);
// wait for PLL clock to be used
while ((MCG_S & MCG_S_CLKST_MASK) != MCG_S_CLKST(3)) ;
// now we're in PEE mode
// configure USB for 48 MHz clock
SIM_CLKDIV2 = SIM_CLKDIV2_USBDIV(1); // USB = 96 MHz PLL / 2
// USB uses PLL clock, trace is CPU clock, CLKOUT=OSCERCLK0
SIM_SOPT2 = SIM_SOPT2_USBSRC | SIM_SOPT2_PLLFLLSEL | SIM_SOPT2_TRACECLKSEL | SIM_SOPT2_CLKOUTSEL(6);
__enable_irq();
main();
}
void __startup(void) {
// The CPU has a watchdog feature which is on by default,
// so we have to configure it to not have nasty reset-surprises
// later on.
startup_watchdog_hook();
// If the system was in VLLS mode, some peripherials and
// the I/O pins are in latched mode. We need to restore
// config and can then acknowledge the isolation to get back
// to normal. For now, we'll just ack TODO: properly do this
if (PMC_REGSC & PMC_REGSC_ACKISO_MASK) PMC_REGSC |= PMC_REGSC_ACKISO_MASK;
// There is a write-once-after-reset register that allows to
// set which power states are available. Let's set it here.
SMC_PMPROT = ENABLED_POWER_MODES;
// For the sake of simplicity, enable all GPIO port clocks
SIM_SCGC5 |= ( SIM_SCGC5_PORTA_MASK
| SIM_SCGC5_PORTB_MASK
| SIM_SCGC5_PORTC_MASK
| SIM_SCGC5_PORTD_MASK
| SIM_SCGC5_PORTE_MASK);
// ----------------------------------------------------------------------------------
// Setup clocks
// ----------------------------------------------------------------------------------
// See section 5 in the Freescale K20 manual for how clock distribution works
// The limits are outlined in section 5.5:
// Core and System clocks: max 72 MHz
// Bus/peripherial clock: max 50 MHz (integer divide of core)
// Flash clock: max 25 MHz
//
// The teensy 3.x has a 16 MHz external oscillator
// So we'll enable the external clock for the OSC module. Since
// we're in high-frequency mode, also enable capacitors
OSC_CR = OSC_CR_SC8P_MASK | OSC_CR_SC2P_MASK; // TODO This does not actually seem enable the ext crystal
// Set MCG to very high frequency crystal and request oscillator. We have
// to do this first so that the divisor will be correct (512 and not 16)
MCG_C2 = MCG_C2_RANGE0(2) | MCG_C2_EREFS0_MASK;
// Select the external reference clock for MCGOUTCLK
// The divider for the FLL has to be chosen that we get something in 31.25 to 39.0625 kHz
// 16MHz / 512 = 31.25 kHz -> set FRDIV to 4
MCG_C1 = MCG_C1_CLKS(2) | MCG_C1_FRDIV(4);
// Wait for OSC to become ready
while ((MCG_S & MCG_S_OSCINIT0_MASK) == 0) ;
// Wait for the FLL to synchronize to external reference
while ((MCG_S & MCG_S_IREFST_MASK) != 0) ;
// Wait for the clock mode to synchronize to external
while ((MCG_S & MCG_S_CLKST_MASK) != MCG_S_CLKST(2)) ;
// The clock is now in FBE mode
#if F_CPU <= 16000000
// For 16 MHz and below, the crystal is fast enough
// -> enable BLPE mode which will disable both FLL and PLL
MCG_C2 = MCG_C2_RANGE0(2) | MCG_C2_EREFS_MASK | MCG_C2_LP_MASK;
#else
// We need PLL to go above 16 MHz
#if F_CPU == 96000000
MCG_C5 = MCG_C5_PRDIV0(3); // 16MHz / 4 = 4MHz (this needs to be 2-4MHz)
MCG_C6 = MCG_C6_PLLS_MASK | MCG_C6_VDIV0(0); // Enable PLL*24 = 96 MHz
#elif F_CPU == 72000000
MCG_C5 = MCG_C5_PRDIV0(5); // 16 MHz / 6 = 2.66 MHz (this needs to be 2-4MHz)
MCG_C6 = MCG_C6_PLLS_MASK | MCG_C6_VDIV0(3); // Enable PLL*27 = 71.82 MHz
#elif F_CPU == 48000000
MCG_C5 = MCG_C5_PRDIV0(7); // 16 MHz / 8 = 2 MHz (this needs to be 2-4MHz)
MCG_C6 = MCG_C6_PLLS_MASK | MCG_C6_VDIV0(0); // Enable PLL*24 = 48 MHz
#elif F_CPU == 24000000
// For 24 MHz, we'll use a 48 MHz PLL and divide in the SIM
MCG_C5 = MCG_C5_PRDIV0(7); // 16 MHz / 8 = 2 MHz (this needs to be 2-4MHz)
MCG_C6 = MCG_C6_PLLS_MASK | MCG_C6_VDIV0(0); // Enable PLL*24 = 48 MHz
#else
#error "Unknown F_CPU value"
#endif
// Now that we setup and enabled the PLL, wait for it to become active
while (!(MCG_S & MCG_S_PLLST_MASK)) ;
// and locked
while (!(MCG_S & MCG_S_LOCK0_MASK)) ;
#endif
// Next up: Setup clock dividers for MCU, peripherials, flash and USB
// This is done by the SIM (System Integration Module)
// There are two registers:
// SIM_CLKDIV1:
// OUTDIV1: Core/system clock divider
// OUTDIV2: Peripherial/Bus clock
// OUTDIV4: Flash clock
// SIM_CLKDIV2:
// USBDIV: Divisor
// USBFRAC: Fraction
// Output is input_clock*(USBFRAC+1)/(USBDIV+1)
//
// USB needs a 48MHz clock, so the divider should be setup accordingly. Also,
// for the USB FS OTG controller to work, the system clock needs to be >= 20 MHz
#if F_CPU == 96000000
// 96 MHz core, 48 MHz bus, 24 MHz flash (OVERCLOCKED!)
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0) | SIM_CLKDIV1_OUTDIV2(1) | SIM_CLKDIV1_OUTDIV4(3);
SIM_CLKDIV2 = SIM_CLKDIV2_USBDIV(1); // 96 * 1/2 = 48
#elif F_CPU == 72000000
// 72 MHz core, 36 MHz bus, 24 MHz flash
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0) | SIM_CLKDIV1_OUTDIV2(1) | SIM_CLKDIV1_OUTDIV4(2);
SIM_CLKDIV2 = SIM_CLKDIV2_USBDIV(2) | SIM_CLKDIV2_USBFRAC_MASK; // 72 * 2/3 = 48
#elif F_CPU == 48000000
// 48 MHz core, 48 MHz bus, 24 MHz flash, USB = 96 / 2
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0) | SIM_CLKDIV1_OUTDIV2(0) | SIM_CLKDIV1_OUTDIV4(1);
SIM_CLKDIV2 = SIM_CLKDIV2_USBDIV(0); // 48 * 1/1 = 48
#elif F_CPU == 24000000
// PLL is 48 MHz
// 24 MHz core, 24 MHz bus, 24 MHz flash
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(1) | SIM_CLKDIV1_OUTDIV2(1) | SIM_CLKDIV1_OUTDIV4(1);
SIM_CLKDIV2 = SIM_CLKDIV2_USBDIV(0); // 48 * 1/1 = 48
// -- For the modes <= 16 MHz, we have the MCG clock on 16 MHz, without FLL/PLL
// Also, USB is not possible
#elif F_CPU == 16000000
// 16 MHz core, 16 MHz bus, 16 MHz flash
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0) | SIM_CLKDIV1_OUTDIV2(0) | SIM_CLKDIV1_OUTDIV4(0);
#elif F_CPU == 8000000
// 8 MHz core, 8 MHz bus, 8 MHz flash
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(1) | SIM_CLKDIV1_OUTDIV2(1) | SIM_CLKDIV1_OUTDIV4(1);
#else
#error "Unsupported F_CPU value"
#endif
// The dividers are set, so we can transition over to PLL for > 16 MHz
#if F_CPU > 16000000
// Switch clock source to PLL, keep FLL divider at 512
MCG_C1 = MCG_C1_CLKS(0) | MCG_C1_FRDIV(4);
// Wait for the clock to sync
while ((MCG_S & MCG_S_CLKST_MASK) != MCG_S_CLKST(3)) ;
// Use PLL for USB and Bus/peripherals, core for trace and put OSCERCLK0 on CLKOUT pin
SIM_SOPT2 = SIM_SOPT2_USBSRC_MASK | SIM_SOPT2_PLLFLLSEL_MASK | SIM_SOPT2_TRACECLKSEL_MASK | SIM_SOPT2_CLKOUTSEL(6);
#endif
// ----------------------------------------------------------------------------------
// Relocate data from flash to RAM as necessary
// ----------------------------------------------------------------------------------
//
// At the minimum, the .data and .bss sections have to be setup in RAM. Also, since
// they are aligned to 4 bytes, we can use uint32s for copying (which is faster than
// byte by byte)
uint32_t * src = &_etext;
uint32_t * dest = &_sdata;
while (dest < &_edata) *dest++ = *src++;
// Also zero out .bss
dest = &_sbss;
while (dest < &_ebss) *dest++ = 0;
// TODO: Relocate interrupt vector to RAM for speed?
// Init systick?
#if ENABLE_SYSTICK_HANDLER
systick_init();
#endif
// Enable interrupts before entering main?
#if ENABLE_INTERRUPTS_ON_STARTUP
interrupt_enable();
#endif
// After everthing is done, call main
main();
// This should be unreachable code as long as main() does not return.
// To avoid running the instruction pointer into places it shouldn't go,
// loop forever
// TODO: Going into sleep would maybe be a better solution
while (1);
}
/**
* @brief K20x clock initialization.
* @note All the involved constants come from the file @p board.h.
* @note This function is meant to be invoked early during the system
* initialization, it is usually invoked from the file
* @p board.c.
* @todo This function needs to be more generic.
*
* @special
*/
void k20x_clock_init(void) {
#if !KINETIS_NO_INIT
/* Disable the watchdog */
WDOG->UNLOCK = 0xC520;
WDOG->UNLOCK = 0xD928;
WDOG->STCTRLH &= ~WDOG_STCTRLH_WDOGEN;
SIM->SCGC5 |= SIM_SCGC5_PORTA |
SIM_SCGC5_PORTB |
SIM_SCGC5_PORTC |
SIM_SCGC5_PORTD |
SIM_SCGC5_PORTE;
#if KINETIS_MCG_MODE == KINETIS_MCG_MODE_FEI
/* This is the default mode at reset. */
/* Configure FEI mode */
MCG->C4 = MCG_C4_DRST_DRS(KINETIS_MCG_FLL_DRS) |
(KINETIS_MCG_FLL_DMX32 ? MCG_C4_DMX32 : 0);
/* Set clock dividers */
SIM->CLKDIV1 = SIM_CLKDIV1_OUTDIV1(KINETIS_CLKDIV1_OUTDIV1-1) |
SIM_CLKDIV1_OUTDIV2(KINETIS_CLKDIV1_OUTDIV2-1) |
SIM_CLKDIV1_OUTDIV4(KINETIS_CLKDIV1_OUTDIV4-1);
SIM->CLKDIV2 = SIM_CLKDIV2_USBDIV(0); /* not strictly necessary since usb_lld will set this */
#elif KINETIS_MCG_MODE == KINETIS_MCG_MODE_PEE
uint32_t ratio, frdiv;
uint32_t ratios[] = { 32, 64, 128, 256, 512, 1024, 1280, 1536 };
uint8_t ratio_quantity = sizeof(ratios) / sizeof(ratios[0]);
uint8_t i;
/* EXTAL0 and XTAL0 */
PORTA->PCR[18] = 0;
PORTA->PCR[19] = 0;
/*
* Start in FEI mode
*/
/* Internal capacitors for crystal */
#if defined(KINETIS_BOARD_OSCILLATOR_SETTING)
OSC0->CR = KINETIS_BOARD_OSCILLATOR_SETTING;
#else /* KINETIS_BOARD_OSCILLATOR_SETTING */
/* Disable the internal capacitors */
OSC0->CR = 0;
#endif /* KINETIS_BOARD_OSCILLATOR_SETTING */
/* TODO: need to add more flexible calculation, specially regarding
* divisors which may not be available depending on the XTAL
* frequency, which would required other registers to be modified.
*/
/* Enable OSC, low power mode */
MCG->C2 = MCG_C2_LOCRE0 | MCG_C2_EREFS0;
if (KINETIS_XTAL_FREQUENCY > 8000000UL)
MCG->C2 |= MCG_C2_RANGE0(2);
else
MCG->C2 |= MCG_C2_RANGE0(1);
frdiv = 7;
ratio = KINETIS_XTAL_FREQUENCY / 31250UL;
for (i = 0; i < ratio_quantity; ++i) {
if (ratio == ratios[i]) {
frdiv = i;
break;
}
}
/* Switch to crystal as clock source, FLL input of 31.25 KHz */
MCG->C1 = MCG_C1_CLKS(2) | MCG_C1_FRDIV(frdiv);
/* Wait for crystal oscillator to begin */
while (!(MCG->S & MCG_S_OSCINIT0));
/* Wait for the FLL to use the oscillator */
while (MCG->S & MCG_S_IREFST);
/* Wait for the MCGOUTCLK to use the oscillator */
while ((MCG->S & MCG_S_CLKST_MASK) != MCG_S_CLKST(2));
/*
* Now in FBE mode
*/
#define KINETIS_PLLIN_FREQUENCY 2000000UL
/*
* Config PLL input for 2 MHz
* TODO: Make sure KINETIS_XTAL_FREQUENCY >= 2Mhz && <= 50Mhz
*/
MCG->C5 = MCG_C5_PRDIV0((KINETIS_XTAL_FREQUENCY/KINETIS_PLLIN_FREQUENCY) - 1);
/*
* Config PLL output to match KINETIS_SYSCLK_FREQUENCY
* TODO: make sure KINETIS_SYSCLK_FREQUENCY is a match
*/
for(i = 24; i < 56; i++)
{
if(i == (KINETIS_PLLCLK_FREQUENCY/KINETIS_PLLIN_FREQUENCY))
{
/* Config PLL to match KINETIS_PLLCLK_FREQUENCY */
MCG->C6 = MCG_C6_PLLS | MCG_C6_VDIV0(i-24);
break;
}
}
if(i>=56) /* Config PLL for 96 MHz output as default setting */
MCG->C6 = MCG_C6_PLLS | MCG_C6_VDIV0(0);
/* Wait for PLL to start using crystal as its input, and to lock */
while ((MCG->S & (MCG_S_PLLST|MCG_S_LOCK0))!=(MCG_S_PLLST|MCG_S_LOCK0));
/*
* Now in PBE mode
*/
/* Set the PLL dividers for the different clocks */
SIM->CLKDIV1 = SIM_CLKDIV1_OUTDIV1(KINETIS_CLKDIV1_OUTDIV1-1) |
SIM_CLKDIV1_OUTDIV2(KINETIS_CLKDIV1_OUTDIV2-1) |
SIM_CLKDIV1_OUTDIV4(KINETIS_CLKDIV1_OUTDIV4-1);
SIM->CLKDIV2 = SIM_CLKDIV2_USBDIV(0);
SIM->SOPT2 = SIM_SOPT2_PLLFLLSEL;
/* Switch to PLL as clock source */
MCG->C1 = MCG_C1_CLKS(0);
/* Wait for PLL clock to be used */
while ((MCG->S & MCG_S_CLKST_MASK) != MCG_S_CLKST_PLL);
/*
* Now in PEE mode
*/
#else /* KINETIS_MCG_MODE == KINETIS_MCG_MODE_PEE */
#error Unimplemented KINETIS_MCG_MODE
#endif /* KINETIS_MCG_MODE == ... */
#endif /* !KINETIS_NO_INIT */
}
/**
* @brief MK20D5 clock initialization.
* @note All the involved constants come from the file @p board.h.
* @note This function is meant to be invoked early during the system
* initialization, it is usually invoked from the file
* @p board.c.
* @todo This function needs to be more generic.
*
* @special
*/
void mk20d50_clock_init(void) {
/* Disable the watchdog */
WDOG->UNLOCK = 0xC520;
WDOG->UNLOCK = 0xD928;
WDOG->STCTRLH &= ~WDOG_STCTRLH_WDOGEN;
SIM->SCGC5 |= SIM_SCGC5_PORTA |
SIM_SCGC5_PORTB |
SIM_SCGC5_PORTC |
SIM_SCGC5_PORTD |
SIM_SCGC5_PORTE;
/* EXTAL0 and XTAL0 */
PORTA->PCR[18] = 0;
PORTA->PCR[19] = 0;
/*
* Start in FEI mode
*/
/* Disable capacitors for crystal */
OSC->CR = 0;
/* Enable OSC, 8-32 MHz range, low power mode */
MCG->C2 = MCG_C2_RANGE0(1) | MCG_C2_LOCRE0 | MCG_C2_EREFS0;
/* Switch to crystal as clock source, FLL input of 8 MHz / 256 = 31.25 KHz */
MCG->C1 = MCG_C1_CLKS(2) | MCG_C1_FRDIV(3);
/* Wait for crystal oscillator to begin */
while (!(MCG->S & MCG_S_OSCINIT0));
/* Wait for the FLL to use the oscillator */
while (MCG->S & MCG_S_IREFST);
/* Wait for the MCGOUTCLK to use the oscillator */
while ((MCG->S & MCG_S_CLKST_MASK) != MCG_S_CLKST(2));
/*
* Now in FBE mode
*/
/* Config PLL input for 2 MHz (8 MHz crystal / 4) */
MCG->C5 = MCG_C5_PRDIV0(3);
/* Config PLL for 96 MHz output */
MCG->C6 = MCG_C6_PLLS | MCG_C6_VDIV0(0);
/* Wait for PLL to start using crystal as its input */
while (!(MCG->S & MCG_S_PLLST));
/* Wait for PLL to lock */
while (!(MCG->S & MCG_S_LOCK0));
/*
* Now in PBE mode
*/
/* Switch to PLL as clock source */
MCG->C1 = MCG_C1_CLKS(0);
/* Wait for PLL clock to be used */
while ((MCG->S & MCG_S_CLKST_MASK) != MCG_S_CLKST_PLL);
/*
* Now in PEE mode
*/
}
/**
* @brief KL2x clocks and PLL initialization.
* @note All the involved constants come from the file @p board.h.
* @note This function should be invoked just after the system reset.
*
* @special
*/
void kl2x_clock_init(void) {
#if !KINETIS_NO_INIT
/* Disable COP watchdog */
SIM->COPC = 0;
/* Enable PORTA */
SIM->SCGC5 |= SIM_SCGC5_PORTA;
/* --- MCG mode: FEI (default out of reset) ---
f_MCGOUTCLK = f_int * F
F is the FLL factor selected by C4[DRST_DRS] and C4[DMX32] bits.
Typical f_MCGOUTCLK = 21 MHz immediately after reset.
C4[DMX32]=0 and C4[DRST_DRS]=00 => FLL factor=640.
C3[SCTRIM] and C4[SCFTRIM] factory trim values apply to f_int. */
/* System oscillator drives 32 kHz clock (OSC32KSEL=0) */
SIM->SOPT1 &= ~SIM_SOPT1_OSC32KSEL_MASK;
#if KINETIS_MCG_MODE == KINETIS_MCG_MODE_FEI
/* This is the default mode at reset. */
/* The MCGOUTCLK is divided by OUTDIV1 and OUTDIV4:
* OUTDIV1 (divider for core/system and bus/flash clock)
* OUTDIV4 (additional divider for bus/flash clock) */
SIM->CLKDIV1 =
SIM_CLKDIV1_OUTDIV1(1) | /* OUTDIV1 = divide-by-2 => 24 MHz */
SIM_CLKDIV1_OUTDIV4(0); /* OUTDIV4 = divide-by-1 => 24 MHz */
#elif KINETIS_MCG_MODE == KINETIS_MCG_MODE_FEE
/*
* FLL Enabled External (FEE) MCG Mode
* 24 MHz core, 12 MHz bus - using 32.768 kHz crystal with FLL.
* f_MCGOUTCLK = (f_ext / FLL_R) * F
* = (32.768 kHz ) *
* FLL_R is the reference divider selected by C1[FRDIV]
* F is the FLL factor selected by C4[DRST_DRS] and C4[DMX32].
*
* Then the core/system and bus/flash clocks are divided:
* f_SYS = f_MCGOUTCLK / OUTDIV1 = 48 MHz / 1 = 48 MHz
* f_BUS = f_MCGOUTCLK / OUTDIV1 / OUTDIV4 = MHz / 4 = 24 MHz
*/
SIM->SOPT2 =
SIM_SOPT2_TPMSRC(1); /* MCGFLLCLK clock or MCGPLLCLK/2 */
/* PLLFLLSEL=0 -> MCGFLLCLK */
/* The MCGOUTCLK is divided by OUTDIV1 and OUTDIV4:
* OUTDIV1 (divider for core/system and bus/flash clock)
* OUTDIV4 (additional divider for bus/flash clock) */
SIM->CLKDIV1 =
SIM_CLKDIV1_OUTDIV1(KINETIS_MCG_FLL_OUTDIV1 - 1) |
SIM_CLKDIV1_OUTDIV4(KINETIS_MCG_FLL_OUTDIV4 - 1);
/* EXTAL0 and XTAL0 */
PORTA->PCR[18] &= ~0x01000700; /* Set PA18 to analog (default) */
PORTA->PCR[19] &= ~0x01000700; /* Set PA19 to analog (default) */
OSC0->CR = 0;
/* From KL25P80M48SF0RM section 24.5.1.1 "Initializing the MCG". */
/* To change from FEI mode to FEE mode: */
/* (1) Select the external clock source in C2 register.
Use low-power OSC mode (HGO0=0) which enables internal feedback
resistor, for 32.768 kHz crystal configuration. */
MCG->C2 =
MCG_C2_RANGE0(0) | /* low frequency range (<= 40 kHz) */
MCG_C2_EREFS0; /* external reference (using a crystal) */
/* (2) Write to C1 to select the clock mode. */
MCG->C1 = /* Clear the IREFS bit to switch to the external reference. */
MCG_C1_CLKS_FLLPLL | /* Use FLL for system clock, MCGCLKOUT. */
MCG_C1_FRDIV(0); /* Don't divide 32kHz ERCLK FLL reference. */
MCG->C6 = 0; /* PLLS=0: Select FLL as MCG source, not PLL */
/* Loop until S[OSCINIT0] is 1, indicating the
crystal selected by C2[EREFS0] has been initialized. */
while ((MCG->S & MCG_S_OSCINIT0) == 0)
;
/* Loop until S[IREFST] is 0, indicating the
external reference is the current reference clock source. */
while ((MCG->S & MCG_S_IREFST) != 0)
; /* Wait until external reference clock is FLL reference. */
/* (1)(e) Loop until S[CLKST] indicates FLL feeds MCGOUTCLK. */
while ((MCG->S & MCG_S_CLKST_MASK) != MCG_S_CLKST_FLL)
; /* Wait until FLL has been selected. */
/* --- MCG mode: FEE --- */
/* Set frequency range for DCO output (MCGFLLCLK). */
MCG->C4 = (KINETIS_MCG_FLL_DMX32 ? MCG_C4_DMX32 : 0) |
MCG_C4_DRST_DRS(KINETIS_MCG_FLL_DRS);
/* Wait for the FLL lock time; t[fll_acquire][max] = 1 ms */
/* TODO - not implemented - is it required? Freescale example code
seems to omit it. */
#elif KINETIS_MCG_MODE == KINETIS_MCG_MODE_PEE
/*
* PLL Enabled External (PEE) MCG Mode
* 48 MHz core, 24 MHz bus - using 8 MHz crystal with PLL.
* f_MCGOUTCLK = (OSCCLK / PLL_R) * M
* = 8 MHz / 2 * 24 = 96 MHz
* PLL_R is the reference divider selected by C5[PRDIV0]
* M is the multiplier selected by C6[VDIV0]
*
* Then the core/system and bus/flash clocks are divided:
* f_SYS = f_MCGOUTCLK / OUTDIV1 = 96 MHz / 2 = 48 MHz
* f_BUS = f_MCGOUTCLK / OUTDIV1 / OUTDIV4 = 96 MHz / 4 = 24 MHz
*/
/* The MCGOUTCLK is divided by OUTDIV1 and OUTDIV4:
* OUTDIV1 (divider for core/system and bus/flash clock)
* OUTDIV4 (additional divider for bus/flash clock) */
SIM->CLKDIV1 =
SIM_CLKDIV1_OUTDIV1(1) | /* OUTDIV1 = divide-by-2 => 48 MHz */
SIM_CLKDIV1_OUTDIV4(1); /* OUTDIV4 = divide-by-2 => 24 MHz */
SIM->SOPT2 =
SIM_SOPT2_TPMSRC(1) | /* MCGFLLCLK clock or MCGPLLCLK/2 */
SIM_SOPT2_PLLFLLSEL; /* PLLFLLSEL=MCGPLLCLK/2 */
/* EXTAL0 and XTAL0 */
PORTA->PCR[18] &= ~0x01000700; /* Set PA18 to analog (default) */
PORTA->PCR[19] &= ~0x01000700; /* Set PA19 to analog (default) */
OSC0->CR = 0;
/* From KL25P80M48SF0RM section 24.5.1.1 "Initializing the MCG". */
/* To change from FEI mode to FBE mode: */
/* (1) Select the external clock source in C2 register.
Use low-power OSC mode (HGO0=0) which enables internal feedback
resistor since FRDM-KL25Z has feedback resistor R25 unpopulated.
Use high-gain mode by setting C2[HGO0] instead if external
feedback resistor Rf is installed. */
MCG->C2 =
MCG_C2_RANGE0(2) | /* very high frequency range */
MCG_C2_EREFS0; /* external reference (using a crystal) */
/* (2) Write to C1 to select the clock mode. */
MCG->C1 = /* Clear the IREFS bit to switch to the external reference. */
MCG_C1_CLKS_ERCLK | /* Use ERCLK for system clock, MCGCLKOUT. */
MCG_C1_FRDIV(3); /* Divide ERCLK / 256 for FLL reference. */
/* Note: FLL reference frequency must be 31.25 kHz to 39.0625 kHz.
8 MHz / 256 = 31.25 kHz. */
MCG->C4 &= ~(MCG_C4_DMX32 | MCG_C4_DRST_DRS_MASK);
MCG->C6 = 0; /* PLLS=0: Select FLL as MCG source, not PLL */
/* (3) Once configuration is set, wait for MCG mode change. */
/* From KL25P80M48SF0RM section 24.5.31: */
/* (1)(c) Loop until S[OSCINIT0] is 1, indicating the
crystal selected by C2[EREFS0] has been initialized. */
while ((MCG->S & MCG_S_OSCINIT0) == 0)
;
/* (1)(d) Loop until S[IREFST] is 0, indicating the
external reference is the current reference clock source. */
while ((MCG->S & MCG_S_IREFST) != 0)
; /* Wait until external reference clock is FLL reference. */
/* (1)(e) Loop until S[CLKST] is 2'b10, indicating
the external reference clock is selected to feed MCGOUTCLK. */
while ((MCG->S & MCG_S_CLKST_MASK) != MCG_S_CLKST_ERCLK)
; /* Wait until external reference clock has been selected. */
/* --- MCG mode: FBE (FLL bypassed, external crystal) ---
Now the MCG is in FBE mode.
Although the FLL is bypassed, it is still on. */
/* (2) Then configure C5[PRDIV0] to generate the
correct PLL reference frequency. */
MCG->C5 = MCG_C5_PRDIV0(1); /* PLL External Reference Divide by 2 */
/* (3) Then from FBE transition to PBE mode. */
/* (3)(b) C6[PLLS]=1 to select PLL. */
/* (3)(b) C6[VDIV0]=5'b0000 (x24) 2 MHz * 24 = 48 MHz. */
MCG->C6 = MCG_C6_PLLS | MCG_C6_VDIV0(0);
/* (3)(d) Loop until S[PLLST], indicating PLL
is the PLLS clock source. */
while ((MCG->S & MCG_S_PLLST) == 0)
; /* wait until PLL is the PLLS clock source. */
/* (3)(e) Loop until S[LOCK0] is set, indicating the PLL has acquired lock. */
/* PLL selected as MCG source. VDIV0=00000 (Multiply=24). */
while ((MCG->S & MCG_S_LOCK0) == 0)
; /* wait until PLL locked */
/* --- MCG mode: PBE (PLL bypassed, external crystal) --- */
/* (4) Transition from PBE mode to PEE mode. */
/* (4)(a) C1[CLKS] = 2'b00 to select PLL output as system clock source. */
// Switch to PEE mode
// Select PLL output (CLKS=0)
// FLL external reference divider (FRDIV=3)
// External reference clock for FLL (IREFS=0)
MCG->C1 = MCG_C1_CLKS(0) |
MCG_C1_FRDIV(3);
/* (4)(b) Loop until S[CLKST] are 2'b11, indicating the PLL output is selected for MCGOUTCLK. */
while ((MCG->S & MCG_S_CLKST_MASK) != MCG_S_CLKST_PLL)
; /* wait until clock switched to PLL output */
/* --- MCG mode: PEE (PLL enabled, external crystal) --- */
#else /* KINETIS_MCG_MODE != KINETIS_MCG_MODE_PEE */
#error Unimplemented KINETIS_MCG_MODE
#endif /* KINETIS_MCG_MODE != KINETIS_MCG_MODE_PEE */
#endif /* !KINETIS_NO_INIT */
}
/**
* @brief MK20D5 clock initialization.
* @note All the involved constants come from the file @p board.h.
* @note This function is meant to be invoked early during the system
* initialization, it is usually invoked from the file
* @p board.c.
* @todo This function needs to be more generic.
*
* @special
*/
void mk20d50_clock_init(void) {
uint32_t ratio, frdiv;
uint32_t ratios[] = { 32, 64, 128, 256, 512, 1024, 1280, 1536 };
int ratio_quantity = sizeof(ratios) / sizeof(ratios[0]);
int i;
/* Disable the watchdog */
WDOG->UNLOCK = 0xC520;
WDOG->UNLOCK = 0xD928;
WDOG->STCTRLH &= ~WDOG_STCTRLH_WDOGEN;
SIM->SCGC5 |= SIM_SCGC5_PORTA |
SIM_SCGC5_PORTB |
SIM_SCGC5_PORTC |
SIM_SCGC5_PORTD |
SIM_SCGC5_PORTE;
/* EXTAL0 and XTAL0 */
PORTA->PCR[18] = 0;
PORTA->PCR[19] = 0;
/*
* Start in FEI mode
*/
/* Disable capacitors for crystal */
OSC->CR = 0;
/* TODO: need to add more flexible calculation, specially regarding
* divisors which may not be available depending on the XTAL
* frequency, which would required other registers to be modified.
*/
/* Enable OSC, low power mode */
MCG->C2 = MCG_C2_LOCRE0 | MCG_C2_EREFS0;
if (KINETIS_XTAL_FREQUENCY > 8000000)
MCG->C2 |= MCG_C2_RANGE0(2);
else
MCG->C2 |= MCG_C2_RANGE0(1);
frdiv = 7;
ratio = KINETIS_XTAL_FREQUENCY / 31250;
for (i = 0; i < ratio_quantity; ++i) {
if (ratio == ratios[i]) {
frdiv = i;
break;
}
}
/* Switch to crystal as clock source, FLL input of 31.25 KHz */
MCG->C1 = MCG_C1_CLKS(2) | MCG_C1_FRDIV(frdiv);
/* Wait for crystal oscillator to begin */
while (!(MCG->S & MCG_S_OSCINIT0));
/* Wait for the FLL to use the oscillator */
while (MCG->S & MCG_S_IREFST);
/* Wait for the MCGOUTCLK to use the oscillator */
while ((MCG->S & MCG_S_CLKST_MASK) != MCG_S_CLKST(2));
/*
* Now in FBE mode
*/
/* Config PLL input for 2 MHz */
MCG->C5 = MCG_C5_PRDIV0((KINETIS_XTAL_FREQUENCY / 2000000) - 1);
/* Config PLL for 96 MHz output */
MCG->C6 = MCG_C6_PLLS | MCG_C6_VDIV0(0);
/* Wait for PLL to start using crystal as its input */
while (!(MCG->S & MCG_S_PLLST));
/* Wait for PLL to lock */
while (!(MCG->S & MCG_S_LOCK0));
/*
* Now in PBE mode
*/
/* Switch to PLL as clock source */
MCG->C1 = MCG_C1_CLKS(0);
/* Wait for PLL clock to be used */
while ((MCG->S & MCG_S_CLKST_MASK) != MCG_S_CLKST_PLL);
/*
* Now in PEE mode
*/
}
// =============================================================================
// 功能：PLL初始化部分，主要对PLL和晶振初始化，是时间从内部时钟切换到外部时钟的主要部
// 分，此处使用PLL0和OSC0作为内部时钟源，经分频和倍频，使内核时钟达到150M
// 参数：crystal_fre_hz,外部晶振频率
// prdiv,PLL分频参数
// vdiv,PLL倍频参数
// 返回：实际配置的MCG输出频率
// =============================================================================
u32 PLL_Init(u32 crystal_fre_hz, u8 prdiv, u8 vdiv)
{
//reset后，系统处于FEI模式，时钟配置过程为：
//FEI--->FBE--->PBE--->PEE(手册640页table25-22)
//默认使用振荡器0，设置振荡器0
// 配置控制寄存器MCG_C2
// 先清bit位，配置高速晶振，high-gain operation，外部晶振
MCG->C2 &= ~(MCG_C2_RANGE0_MASK | MCG_C2_HGO0_MASK | MCG_C2_EREFS0_MASK);
MCG->C2 |= (MCG_C2_RANGE0(1)
| (0 << MCG_C2_HGO0_SHIFT)
| (0 << MCG_C2_EREFS0_SHIFT));
// 配置控制寄存器MCG_C1
//先清bit位，CLK为外部时钟，FRDIV为5时，配置分频为1024，即配置FLL处于
//31.25-39.0625 kHz 之间
MCG->C1 &= ~(MCG_C1_CLKS_MASK | MCG_C1_FRDIV_MASK | MCG_C1_IREFS_MASK);
MCG->C1 = MCG_C1_CLKS(2) | MCG_C1_FRDIV(5);
while((MCG->S & MCG_S_IREFST_MASK)); //等待FLL时钟转为外部源
while(((MCG->S & MCG_S_CLKST_MASK) >> MCG_S_CLKST_SHIFT) != 0x2);
// Now in FBE
MCG->C6 |= MCG_C6_CME0_MASK;
// start Configure PLL0
MCG->C5 &= ~MCG_C5_PLLREFSEL0_MASK; // ensure OSC0
MCG->C11 &= ~MCG_C11_PLLCS_MASK; // select PLL0
// Configure MCG_C5
MCG->C5 &= ~MCG_C5_PRDIV0_MASK; // clear settings
MCG->C5 |= MCG_C5_PRDIV0(prdiv - 1); //set PLL ref divider
// Configure MCG_C6
MCG->C6 &= ~MCG_C6_VDIV0_MASK; // clear settings
MCG->C6 |= MCG_C6_PLLS_MASK | MCG_C6_VDIV0(vdiv - 16); // write new VDIV
while(!(MCG->S & MCG_S_PLLST_MASK)); // wait for PLLST status bit to set
while(!(MCG->S & MCG_S_LOCK0_MASK)); // Wait for LOCK bit to set
// Use actual PLL settings to calculate PLL frequency
prdiv = ((MCG->C5 & MCG_C5_PRDIV0_MASK) + 1);
vdiv = ((MCG->C6 & MCG_C6_VDIV0_MASK) + 16);
// now in PBE
MCG->C1 &= ~MCG_C1_CLKS_MASK; // 清CLKS，选择MCG_OUT源为PLL
while(((MCG->S & MCG_S_CLKST_MASK) >> MCG_S_CLKST_SHIFT) != 0x3);
// start Configure PLL1 if needed, for DDR,so, CLK = 100MHz
#if (CN_CFG_DDR_USED == 1)
// Configure MCG_C12
MCG->C11 &= ~MCG_C11_PLLREFSEL1_MASK; // Clear select bit to choose OSC0
MCG->C11 &= ~MCG_C11_PRDIV1_MASK;
MCG->C11 |= MCG_C11_PRDIV1(5 - 1);
MCG->C12 &= ~MCG_C12_VDIV1_MASK; // clear VDIV settings
MCG->C12 |= MCG_C12_VDIV1(24 - 16); // write new VDIV and enable PLL
// Now enable the PLL
MCG->C11 |= MCG_C11_PLLCLKEN1_MASK; // Set PLLCLKEN2 to enable PLL1
while(!(MCG->S2 & MCG_S2_LOCK1_MASK)); // Wait for PLL1 locked
#endif
//MCGOUT equals PLL output frequency/2
return (((crystal_fre_hz / prdiv) * vdiv) / 2);
}
void __pe_initialize_hardware(void)
{
/*** !!! Here you can place your own code before PE initialization using property "User code before PE initialization" on the build options tab. !!! ***/
/*** ### MK21FN1M0VMC12 "Cpu" init code ... ***/
/*** PE initialization code after reset ***/
/* Disable the WDOG module */
/* 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;
#if MQX_ENABLE_LOW_POWER
/* Reset from LLWU wake up source */
if (_lpm_get_reset_source() == MQX_RESET_SOURCE_LLWU)
{
PMC_REGSC |= PMC_REGSC_ACKISO_MASK;
}
#endif
/* SIM_SCGC6: RTC=1 */
SIM_SCGC6 |= SIM_SCGC6_RTC_MASK;
if ((RTC_CR & RTC_CR_OSCE_MASK) == 0u) { /* Only if the OSCILLATOR is not already enabled */
/* RTC_CR: SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
RTC_CR &= (uint32_t)~(uint32_t)(
RTC_CR_SC2P_MASK |
RTC_CR_SC4P_MASK |
RTC_CR_SC8P_MASK |
RTC_CR_SC16P_MASK
);
/* RTC_CR: OSCE=1 */
RTC_CR |= RTC_CR_OSCE_MASK;
/* RTC_CR: CLKO=0 */
RTC_CR &= (uint32_t)~(uint32_t)(RTC_CR_CLKO_MASK);
}
/* System clock initialization */
/* SIM_CLKDIV1: OUTDIV1=0,OUTDIV2=1,OUTDIV3=3,OUTDIV4=3,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0x00) |
SIM_CLKDIV1_OUTDIV2(0x01) |
SIM_CLKDIV1_OUTDIV3(0x03) |
SIM_CLKDIV1_OUTDIV4(0x03); /* Set the system prescalers to safe value */
/* SIM_SCGC5: PORTD=1,PORTC=1,PORTA=1 */
SIM_SCGC5 |= SIM_SCGC5_PORTD_MASK |
SIM_SCGC5_PORTC_MASK |
SIM_SCGC5_PORTA_MASK; /* Enable clock gate for ports to enable pin routing */
/* SIM_CLKDIV1: OUTDIV1=0,OUTDIV2=1,OUTDIV3=2,OUTDIV4=4,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0x00) |
SIM_CLKDIV1_OUTDIV2(0x01) |
SIM_CLKDIV1_OUTDIV3(0x02) |
SIM_CLKDIV1_OUTDIV4(0x04); /* Update system prescalers */
/* SIM_CLKDIV2: USBDIV=0,USBFRAC=0 */
SIM_CLKDIV2 = (uint32_t)0x09UL; /* Update USB clock prescalers */
/* SIM_SOPT2: PLLFLLSEL=1 */
SIM_SOPT2 |= SIM_SOPT2_PLLFLLSEL_MASK; /* Select PLL as a clock source for various peripherals */
/* SIM_SOPT1: OSC32KSEL=0 */
SIM_SOPT1 &= (uint32_t)~(uint32_t)(SIM_SOPT1_OSC32KSEL(0x03)); /* System oscillator drives 32 kHz clock for various peripherals */
/* PORTA_PCR18: ISF=0,MUX=0 */
PORTA_PCR18 &= (uint32_t)~(uint32_t)((PORT_PCR_ISF_MASK | PORT_PCR_MUX(0x07)));
/* PORTA_PCR19: ISF=0,MUX=0 */
PORTA_PCR19 &= (uint32_t)~(uint32_t)((PORT_PCR_ISF_MASK | PORT_PCR_MUX(0x07)));
/* Switch to FBE Mode */
/* MCG_C2: LOCRE0=0,??=0,RANGE0=2,HGO0=0,EREFS0=1,LP=0,IRCS=0 */
MCG_C2 = (MCG_C2_RANGE0(0x02) | MCG_C2_EREFS0_MASK);
/* OSC_CR: ERCLKEN=1,??=0,EREFSTEN=1,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC_CR = (OSC_CR_ERCLKEN_MASK | OSC_CR_EREFSTEN_MASK);
/* MCG_C7: OSCSEL=0 */
MCG_C7 &= (uint8_t)~(uint8_t)(MCG_C7_OSCSEL_MASK);
/* MCG_C1: CLKS=2,FRDIV=3,IREFS=0,IRCLKEN=0,IREFSTEN=0 */
MCG_C1 = (MCG_C1_CLKS(0x02) | MCG_C1_FRDIV(0x03));
/* MCG_C4: DMX32=0,DRST_DRS=0 */
MCG_C4 &= (uint8_t)~(uint8_t)((MCG_C4_DMX32_MASK | MCG_C4_DRST_DRS(0x03)));
/* MCG_C5: ??=0,PLLCLKEN0=0,PLLSTEN0=0,PRDIV0=1 */
MCG_C5 = MCG_C5_PRDIV0(0x01);
/* MCG_C6: LOLIE0=0,PLLS=0,CME0=0,VDIV0=6 */
MCG_C6 = MCG_C6_VDIV0(0x06);
while((MCG_S & MCG_S_OSCINIT0_MASK) == 0x00U) { /* Check that the oscillator is running */
}
while((MCG_S & MCG_S_IREFST_MASK) != 0x00U) { /* Check that the source of the FLL reference clock is the external reference clock. */
}
while((MCG_S & 0x0CU) != 0x08U) { /* Wait until external reference clock is selected as MCG output */
}
/* Switch to PBE Mode */
/* MCG_C6: LOLIE0=0,PLLS=1,CME0=0,VDIV0=6 */
MCG_C6 = (MCG_C6_PLLS_MASK | MCG_C6_VDIV0(0x06));
while((MCG_S & 0x0CU) != 0x08U) { /* Wait until external reference clock is selected as MCG output */
}
while((MCG_S & MCG_S_LOCK0_MASK) == 0x00U) { /* Wait until locked */
}
/* Switch to PEE Mode */
/* MCG_C1: CLKS=0,FRDIV=3,IREFS=0,IRCLKEN=0,IREFSTEN=0 */
MCG_C1 = (MCG_C1_CLKS(0x00) | MCG_C1_FRDIV(0x03));
while((MCG_S & 0x0CU) != 0x0CU) { /* Wait until output of the PLL is selected */
}
/*** End of PE initialization code after reset ***/
/*** !!! Here you can place your own code after PE initialization using property "User code after PE initialization" on the build options tab. !!! ***/
}
/*lint -esym(765,Cpu_Interrupt) Disable MISRA rule (8.10) checking for symbols (Cpu_Interrupt). */
void __init_hardware(void)
{
/*** !!! Here you can place your own code before PE initialization using property "User code before PE initialization" on the build options tab. !!! ***/
/*** ### MK22FX512VLQ12 "Cpu" init code ... ***/
/*** PE initialization code after reset ***/
SCB_VTOR = (uint32_t)(&__vect_table); /* Set the interrupt vector table position */
/* Disable the WDOG module */
/* 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;
/* System clock initialization */
/* SIM_CLKDIV1: OUTDIV1=0,OUTDIV2=1,OUTDIV3=3,OUTDIV4=3,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0x00) |
SIM_CLKDIV1_OUTDIV2(0x01) |
SIM_CLKDIV1_OUTDIV3(0x03) |
SIM_CLKDIV1_OUTDIV4(0x03); /* Set the system prescalers to safe value */
/* SIM_SCGC5: PORTE=1,PORTD=1,PORTB=1,PORTA=1 */
SIM_SCGC5 |= SIM_SCGC5_PORTE_MASK |
SIM_SCGC5_PORTD_MASK |
SIM_SCGC5_PORTB_MASK |
SIM_SCGC5_PORTA_MASK; /* Enable clock gate for ports to enable pin routing */
/* SIM_SCGC5: LPTMR=1 */
SIM_SCGC5 |= SIM_SCGC5_LPTMR_MASK;
if ((PMC_REGSC & PMC_REGSC_ACKISO_MASK) != 0x0U) {
/* PMC_REGSC: ACKISO=1 */
PMC_REGSC |= PMC_REGSC_ACKISO_MASK; /* Release IO pads after wakeup from VLLS mode. */
}
/* SIM_CLKDIV1: OUTDIV1=0,OUTDIV2=1,OUTDIV3=4,OUTDIV4=4,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0,??=0 */
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0x00) |
SIM_CLKDIV1_OUTDIV2(0x01) |
SIM_CLKDIV1_OUTDIV3(0x04) |
SIM_CLKDIV1_OUTDIV4(0x04); /* Update system prescalers */
/* SIM_SOPT2: PLLFLLSEL=1 */
SIM_SOPT2 |= SIM_SOPT2_PLLFLLSEL_MASK; /* Select PLL as a clock source for various peripherals */
/* SIM_SOPT1: OSC32KSEL=3 */
SIM_SOPT1 |= SIM_SOPT1_OSC32KSEL(0x03); /* LPO 1kHz oscillator drives 32 kHz clock for various peripherals */
/* PORTA_PCR18: ISF=0,MUX=0 */
PORTA_PCR18 &= (uint32_t)~(uint32_t)((PORT_PCR_ISF_MASK | PORT_PCR_MUX(0x07)));
/* PORTA_PCR19: ISF=0,MUX=0 */
PORTA_PCR19 &= (uint32_t)~(uint32_t)((PORT_PCR_ISF_MASK | PORT_PCR_MUX(0x07)));
/* Switch to FBE Mode */
/* MCG_C2: LOCRE0=0,??=0,RANGE0=2,HGO0=0,EREFS0=1,LP=0,IRCS=0 */
MCG_C2 = (MCG_C2_RANGE0(0x02) | MCG_C2_EREFS0_MASK);
/* OSC_CR: ERCLKEN=1,??=0,EREFSTEN=0,??=0,SC2P=0,SC4P=0,SC8P=0,SC16P=0 */
OSC_CR = OSC_CR_ERCLKEN_MASK;
/* MCG_C7: OSCSEL=0 */
MCG_C7 &= (uint8_t)~(uint8_t)(MCG_C7_OSCSEL_MASK);
/* MCG_C1: CLKS=2,FRDIV=3,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
MCG_C1 = (MCG_C1_CLKS(0x02) | MCG_C1_FRDIV(0x03) | MCG_C1_IRCLKEN_MASK);
/* MCG_C4: DMX32=0,DRST_DRS=0 */
MCG_C4 &= (uint8_t)~(uint8_t)((MCG_C4_DMX32_MASK | MCG_C4_DRST_DRS(0x03)));
/* MCG_C5: ??=0,PLLCLKEN0=0,PLLSTEN0=0,PRDIV0=1 */
MCG_C5 = MCG_C5_PRDIV0(0x01);
/* MCG_C6: LOLIE0=0,PLLS=0,CME0=0,VDIV0=6 */
MCG_C6 = MCG_C6_VDIV0(0x06);
while((MCG_S & MCG_S_OSCINIT0_MASK) == 0x00U) { /* Check that the oscillator is running */
}
while((MCG_S & MCG_S_IREFST_MASK) != 0x00U) { /* Check that the source of the FLL reference clock is the external reference clock. */
}
while((MCG_S & 0x0CU) != 0x08U) { /* Wait until external reference clock is selected as MCG output */
}
/* Switch to PBE Mode */
/* MCG_C1: CLKS=2,FRDIV=4,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
MCG_C1 = (MCG_C1_CLKS(0x02) | MCG_C1_FRDIV(0x04) | MCG_C1_IRCLKEN_MASK);
/* MCG_C6: LOLIE0=0,PLLS=1,CME0=0,VDIV0=6 */
MCG_C6 = (MCG_C6_PLLS_MASK | MCG_C6_VDIV0(0x06));
while((MCG_S & 0x0CU) != 0x08U) { /* Wait until external reference clock is selected as MCG output */
}
while((MCG_S & MCG_S_LOCK0_MASK) == 0x00U) { /* Wait until locked */
}
/* Switch to PEE Mode */
/* MCG_C1: CLKS=0,FRDIV=4,IREFS=0,IRCLKEN=1,IREFSTEN=0 */
MCG_C1 = (MCG_C1_CLKS(0x00) | MCG_C1_FRDIV(0x04) | MCG_C1_IRCLKEN_MASK);
while((MCG_S & 0x0CU) != 0x0CU) { /* Wait until output of the PLL is selected */
}
/*** End of PE initialization code after reset ***/
/*** !!! Here you can place your own code after PE initialization using property "User code after PE initialization" on the build options tab. !!! ***/
}
/*! Sets up the clock for USB operation (out of RESET)
*!
*! MCGOUTCLK = 48MHz
*! core/platform/system clock = PLL (48MHz),
*! bus clock = PLL (48MHz),
*! flash clock = PLL/2 (24MHz)
*!
*! Assumes 8 MHz external crystal
*!
*! Modes: FEI [FLL engaged internal] ->
*! FBE [FLL bypassed external] ->
*! PBE [PLL bypassed external] ->
*! PEE [PLL engaged external]
*!
*! Refer 24.5.3.1 of K20 Family reference
*/
void initClock(void) {
MCG_C7 = 0; // OSCSEL = 0 => Crystal Osc
// Out of reset MCG is in FEI mode
// Configure the Crystal Oscillator
OSC0_CR = OSC_CR_SC16P_MASK;
// 1. Switch from FEI (FLL engaged internal) to FBE (FLL bypassed external)
// 1 a) Set up crystal
MCG_C2 = // oscillator in low power mode (w/o Rf)
MCG_C2_EREFS0_MASK | // because crystal is being used
MCG_C2_RANGE0(1) | // 4 or 8 MHz is in high frequency range
MCG_C2_IRCS_MASK;
// 1 b) Select clock mode
MCG_C1 = MCG_C1_CLKS(2) | // CLKS = 10 -> External reference clock
MCG_C1_FRDIV(FRDIV_VALUE) | // FRDIV = 2,3 -> 8MHz,4MHz/256 = 31.25 kHz
MCG_C1_IRCLKEN_MASK; // IRCLKEN = 1 -> MCGIRCLK active
// Make sure - reset default
MCG_C4 &= ~(MCG_C4_DMX32_MASK|MCG_C4_DRST_DRS_MASK);
// 1 c) Wait for crystal to start up
while ((MCG_S & MCG_S_OSCINIT0_MASK) == 0) {
}
// 1 d) Wait for mode change
while ((MCG_S & MCG_S_IREFST_MASK) != 0) {
}
// 1 e) Wait for MCGOUT indicating that the external reference to be fed to MCGOUT
while ((MCG_S & MCG_S_CLKST_MASK) != MCG_S_CLKST(2)) {
}
// 2. Configure PLL Ref. Freq.
// 2 a) Set PRDIV for correct range
MCG_C5 = MCG_C5_PLLCLKEN0_MASK |
MCG_C5_PRDIV0(PRDIV_VALUE); // PRDIV=3,1, PLL Ref Freq. = 8MHz,4MHz/4 => 2 MHz
MCG_C6 = 0;
// 3. FBE => BLPE => PBE
// 3 a) BLPE
MCG_C2 = // oscillator in low power mode (w/o external Rf)
MCG_C2_EREFS0_MASK | // because crystal is being used
MCG_C2_RANGE0(1) | // 4 or 8 MHz is in high frequency range
MCG_C2_IRCS_MASK ;
// 3 b) BLPE/PBE
MCG_C6 = MCG_C6_PLLS_MASK|MCG_C6_VDIV0(0); // 2MHz x 24 = 96MHz
// 3 c) BPE
MCG_C2 = // oscillator in low power mode (w/o Rf)
MCG_C2_EREFS0_MASK | // because crystal is being used
MCG_C2_RANGE0(1) | // 4 or 8 MHz is in high frequency range
MCG_C2_IRCS_MASK;
// 3 d) Wait until PLLS clock source changes to the PLL
while((MCG_S & MCG_S_PLLST_MASK) == 0) {
}
// 3 e) Wait for PLL to acquired lock
while((MCG_S & MCG_S_LOCK0_MASK) == 0) {
}
// Set up the SIM clock dividers BEFORE switching to the PLL to ensure the
// system clock speeds are in spec.
#if 1 || (CPU == MK20D5)
{
// Disable Flash pre-fetch while changing flash divider
uint32_t temp = FMC_PFAPR;
FMC_PFAPR |= FMC_PFAPR_M3AP_MASK|FMC_PFAPR_M2AP_MASK|FMC_PFAPR_M1AP_MASK|FMC_PFAPR_M0AP_MASK;
// core/platform/system clock = PLL (48MHz), bus clock = PLL (48MHz), flash clock = PLL/2 (24MHz)
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0) | SIM_CLKDIV1_OUTDIV2(0) | SIM_CLKDIV1_OUTDIV4(1);
FMC_PFAPR = temp;
}
#elif CPU == MKL25Z4
{
// Disable Flash pre-fetch while changing flash divider
uint32_t temp = FMC_PFAPR;
FMC_PFAPR |= FMC_PFAPR_M3AP_MASK|FMC_PFAPR_M2AP_MASK|FMC_PFAPR_M1AP_MASK|FMC_PFAPR_M0AP_MASK;
// core/platform/system clock = PLL/2 (48MHz), bus clock/flash clock = PLL/2/2 (24MHz)
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(1) | SIM_CLKDIV1_OUTDIV4(1);
FMC_PFAPR = temp;
}
#endif
// 4. PBE mode transitions into PEE mode:
// 4 a) Select clock mode
MCG_C1 = MCG_C1_CLKS(0) | // CLKS = 0 -> FLL or PLL is selected
MCG_C1_FRDIV(FRDIV_VALUE) | // FRDIV = 2,3 -> 8MHz,4MHz/256 = 31.25 kHz
MCG_C1_IRCLKEN_MASK;
// 4 b) Wait for clock stable
while ((MCG_S & MCG_S_CLKST_MASK) != (3<<MCG_S_CLKST_SHIFT)) {
}
// Now MCGOUTCLK=MCGPLLCLK=[(2 MHz / 1) * 24] = 48 MHz
// Basic clock selection
#if 1 || (CPU == MK20D5)
// Peripheral clock choice (incl. USB), USBCLK = MCGCLK
SIM_SOPT2 |= SIM_SOPT2_PLLFLLSEL_MASK | // PLL rather than FLL for peripheral clock
SIM_SOPT2_USBSRC_MASK; // MCGPLLCLK Source as USB clock (48MHz req.)
// USB Clock = Divider input clock x [(USBFRAC+1)/(USBDIV+1)]
// USBDIV 0-7, USBFRAC 0-1
// SIM_CLKDIV2 = SIM_CLKDIV2_USBDIV(1);
SIM_CLKDIV2 = SIM_CLKDIV2_USBDIV(0);
#elif CPU == MKL25Z4
SIM_SOPT2 = SIM_SOPT2_UART0SRC(1) | // MCGPLLCLK/2 as UART0 clock
SIM_SOPT2_TPMSRC(1) | // MCGPLLCLK/2 as TPM clock
SIM_SOPT2_PLLFLLSEL_MASK | // PLL rather than FLL for peripheral clock
SIM_SOPT2_USBSRC_MASK; // MCGPLLCLK/2 Source as USB clock (48MHz req.)
#else
#error "CPU not set"
#endif
}
