/*! Sets up the clock out of RESET
*!
*/
void clock_initialise(void) {
#ifdef ENABLE_CLKOUT
showClocks();
#endif
#if (CLOCK_MODE == CLOCK_MODE_RESET)
// No clock setup
#else
// XTAL/EXTAL Pins
SIM_SCGC6 |= SIM_SCGC6_PORTB_MASK;
MXC_PTBPF1 = (MXC_PTBPF1&~MXC_PTBPF1_B6_MASK)|MXC_PTBPF1_B6(0);
MXC_PTBPF2 = (MXC_PTBPF2&~MXC_PTBPF2_B5_MASK)|MXC_PTBPF2_B5(0);
// Configure OSC2 (XTAL1/EXTAL1
OSC1_CR = OSC1_CR_ERCLKEN_M|OSC1_CR_EREFSTEN_M|OSC1_CR_SCP_M;
// Configure OSC2 (XTAL2/EXTAL2
OSC2_CR = OSC2_CR_ERCLKEN_M|OSC2_CR_EREFSTEN_M|OSC2_CR_SCP_M;
// Configure OSC1 (XTAL1/EXTAL1
SIM_OSC1 = SIM_OSC1_OSC1EN_M|SIM_OSC1_OSC1RANGE_M|SIM_OSC1_OSC1HGO_M|SIM_OSC1_OSC1EREFS_M;
// Out of reset MCG is in FEI mode
// =============================================================
// Switch from FEI -> FEI/FBI/FEE/FBE
// =============================================================
// Set up crystal or external clock source
MCG_C2 = MCG_C2_RANGE_M | // RANGE = 0,1,2 -> Oscillator low/high/very high clock range
MCG_C2_HGO_M | // HGO = 0,1 -> Oscillator low power/high gain
MCG_C2_EREFS_M | // EREFS = 0,1 -> Select external clock/crystal oscillator
MCG_C2_IRCS_M; // IRCS = 0,1 -> Select slow/fast internal clock for internal reference
SIM_CLKDIV0 = SIM_CLKDIV0_OUTDIV(3);
#if ((CLOCK_MODE == CLOCK_MODE_FEI) || (CLOCK_MODE == CLOCK_MODE_FBI) || (CLOCK_MODE == CLOCK_MODE_BLPI) )
// Transition via FBI
//=====================================
#define BYPASS (1) // CLKS value used while FLL locks
MCG_C1 = MCG_C1_CLKS(BYPASS) | // CLKS = 1 -> Internal reference source while PLL locks
MCG_C1_FRDIV_M | // FRDIV = N -> XTAL/2^n ~ 31.25 kHz
MCG_C1_IREFS_M | // IREFS = 0,1 -> External/Slow IRC for FLL source
MCG_C1_IRCLKEN_M | // IRCLKEN = 0,1 -> IRCLK disable/enable
MCG_C1_IREFSTEN_M; // IREFSTEN = 0,1 -> Internal reference enabled in STOP mode
// Wait for S_IREFST to indicate FLL Reference has switched
do {
__asm__("nop");
} while ((MCG_S & MCG_S_IREFST_MASK) != (MCG_C1_IREFS_V<<MCG_S_IREFST_SHIFT));
// Wait for S_CLKST to indicating that OUTCLK has switched to bypass PLL/FLL
do {
__asm__("nop");
} while ((MCG_S & MCG_S_CLKST_MASK) != MCG_S_CLKST(BYPASS));
// Set FLL Parameters
MCG_C4 = (MCG_C4&~(MCG_C4_DMX32_MASK|MCG_C4_DRST_DRS_MASK))|MCG_C4_DMX32_M|MCG_C4_DRST_DRS_M;
#endif
#if ((CLOCK_MODE == CLOCK_MODE_FBE) || (CLOCK_MODE == CLOCK_MODE_FEE) || (CLOCK_MODE == CLOCK_MODE_PLBE) || (CLOCK_MODE == CLOCK_MODE_PBE) || (CLOCK_MODE == CLOCK_MODE_PEE))
// Transition via FBE
//=====================================
#define BYPASS (2) // CLKS value used while PLL locks
MCG_C1 = MCG_C1_CLKS(BYPASS) | // CLKS = 2 -> External reference source while PLL locks
MCG_C1_FRDIV_M | // FRDIV = N -> XTAL/2^n ~ 31.25 kHz
MCG_C1_IREFS_M | // IREFS = 0,1 -> External/Slow IRC for FLL source
MCG_C1_IRCLKEN_M | // IRCLKEN = 0,1 -> IRCLK disable/enable
MCG_C1_IREFSTEN_M; // IREFSTEN = 0,1 -> Internal reference enabled in STOP mode
#if (MCG_C2_EREFS_V != 0)
// Wait for oscillator stable (if used)
do {
__asm__("nop");
} while ((MCG_S & MCG_S_OSCINIT_MASK) == 0);
#endif
// Wait for S_IREFST to indicate FLL Reference has switched
do {
__asm__("nop");
} while ((MCG_S & MCG_S_IREFST_MASK) != (MCG_C1_IREFS_V<<MCG_S_IREFST_SHIFT));
// Wait for S_CLKST to indicating that OUTCLK has switched to bypass PLL/FLL
do {
__asm__("nop");
} while ((MCG_S & MCG_S_CLKST_MASK) != MCG_S_CLKST(BYPASS));
// Set FLL Parameters
MCG_C4 = (MCG_C4&~(MCG_C4_DMX32_MASK|MCG_C4_DRST_DRS_MASK))|MCG_C4_DMX32_M|MCG_C4_DRST_DRS_M;
#endif
#if ((CLOCK_MODE == CLOCK_MODE_PBE) || (CLOCK_MODE == CLOCK_MODE_PEE))
// Configure PLL Reference Frequency
// =============================================================
MCG_C5 = MCG_C5_PLLCLKEN_M | // PLLCLKEN = 0,1 -> PLL -/enabled (irrespective of PLLS)
MCG_C5_PLLSTEN_M | // PLLSTEN0 = 0,1 -> disabled/enabled in normal stop mode
MCG_C5_PRDIV_M; // PRDIV0 = N -> PLL divider so PLL Ref. Freq. = 2-4 MHz
// Transition via PBE
// =============================================================
MCG_C6 = MCG_C6_LOLIE_M |
MCG_C6_PLLS_M | // PLLS = 0,1 -> Enable PLL
MCG_C6_CME_M | // CME0 = 0,1 -> Disable/enable clock monitor
MCG_C6_VDIV_M; // VDIV0 = N -> PLL Multiplication factor
// Wait for PLL to lock
do {
__asm__("nop");
} while((MCG_S & MCG_S_LOCK_MASK) == 0);
// Wait until PLLS clock source changes to the PLL clock out
do {
__asm__("nop");
} while((MCG_S & MCG_S_PLLST_MASK) == 0);
#endif
#if ((CLOCK_MODE == CLOCK_MODE_FEI) || (CLOCK_MODE == CLOCK_MODE_FEE))
// Wait for FLL to lock
do {
__asm__("nop");
} while ((MCG_C4&MCG_C4_DRST_DRS_MASK) != MCG_C4_DRST_DRS_M);
#endif
// Select FEI/FBI/FEE/FBE/PBE/PEE clock mode
MCG_C1 = MCG_C1_CLKS_M | // CLKS = 0,1,2 -> Select FLL/IRCSCLK/ERCLK
MCG_C1_FRDIV_M | // FRDIV = N -> XTAL/2^n ~ 31.25 kHz
MCG_C1_IREFS_M | // IREFS = 0,1 -> External/Slow IRC for FLL source
MCG_C1_IRCLKEN_M | // IRCLKEN = 0,1 -> IRCLK disable/enable
MCG_C1_IREFSTEN_M; // IREFSTEN = 0,1 -> Internal reference enabled in STOP mode
// Wait for mode change
do {
__asm__("nop");
} while ((MCG_S & MCG_S_IREFST_MASK) != (MCG_C1_IREFS_V<<MCG_S_IREFST_SHIFT));
#if defined (MCG_C6_PLLS_V) && (MCG_C1_CLKS_V == 0) // FLL or PLL
#define MCG_S_CLKST_M MCG_S_CLKST(MCG_C6_PLLS_V?3:0)
#else
#define MCG_S_CLKST_M MCG_S_CLKST(MCG_C1_CLKS_V)
#endif
// Wait for S_CLKST to indicating that OUTCLK has switched
do {
__asm__("nop");
} while ((MCG_S & MCG_S_CLKST_MASK) != MCG_S_CLKST_M);
#if (CLOCK_MODE == CLOCK_MODE_BLPE) || (CLOCK_MODE == CLOCK_MODE_BLPI)
// Select BLPE/BLPI clock mode
MCG_C2 =
MCG_C2_LOCRE_M | // LOCRE0 = 0,1 -> Loss of clock reset
MCG_C2_RANGE_M | // RANGE0 = 0,1,2 -> Oscillator low/high/very high clock range
MCG_C2_HGO_M | // HGO0 = 0,1 -> Oscillator low power/high gain
MCG_C2_EREFS_M | // EREFS0 = 0,1 -> Select external clock/crystal oscillator
MCG_C2_LP_M | // LP = 0,1 -> Select FLL enabled/disabled in bypass mode
MCG_C2_IRCS_M; // IRCS = 0,1 -> Select slow/fast internal clock for internal reference
#endif // (CLOCK_MODE == CLOCK_MODE_BLPE) || (CLOCK_MODE == CLOCK_MODE_BLPI)
#endif // (CLOCK_MODE == CLOCK_MODE_RESET)
// Basic clock multiplexing
#if defined(MCU_mcf51jf128)
// SIM_SOPT2 = SIM_SOPT2_UART0SRC_M | // UART0 clock - 0,1,2,3 -> Disabled, (MCGFLLCLK, MCGPLLCLK/2), OSCERCLK, MCGIRCLK
// SIM_SOPT2_TPMSRC_M ; // TPM2 source
#else
#error "CPU not set"
#endif
#ifdef SIM_CLKDIV1_USBFRAC_MASK
SIM_CLKDIV1 = SIM_CLKDIV1_USBDIV_M | SIM_CLKDIV1_USBFRAC_M | SIM_CLKDIV1_USBSRC_M;
#endif
SIM_CLKDIV0 = SIM_CLKDIV0_M;
SystemCoreClockUpdate();
}
/*****************************************************************************
* @name MCG_Init
*
* @brief: Initialization of the Multiple Clock Generator.
*
* @param : None
*
* @return : None
*****************************************************************************
* Provides clocking options for the device, including a phase-locked
* loop(PLL) and frequency-locked loop (FLL) for multiplying slower reference
* clock sources
****************************************************************************/
static void
MCG_Init()
{
SIM_SCGC5 |= SIM_SCGC5_MCG_MASK;
#ifndef EXTERNAL_OSC
SIM_SCGC5 |= SIM_SCGC5_OSC2_MASK;
#endif
/* First move to FBE mode */
/* Enable external oscillator, RANGE=1, HGO=1, EREFS=1, LP=0, IRCS=0 */
#ifdef EXTERNAL_OSC
MCG_C2 = 0;
#else
MCG_C2 = MCG_C2_RANGE(1) | MCG_C2_HGO_MASK | MCG_C2_EREFS_MASK;
#endif
/* 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 */
#ifndef EXTERNAL_OSC
while (!(MCG_S & MCG_S_OSCINIT_MASK))
{;}
#endif
/* 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)
{;}
/* Configure PLL Ref Divider, PLLCLKEN=0, PLLSTEN=0, PRDIV=5
The crystal frequency is used to select the PRDIV value. Only even frequency crystals are supported
that will produce a 2MHz reference clock to the PLL. */
MCG_C5 = MCG_C5_PRDIV(BSP_REF_CLOCK_DIV); // Set PLL ref. divider to match the crystal used
/* Ensure MCG_C6 is at the reset default of 0. LOLIE disabled, PLL disabled, clk. monitor disabled, PLL VCO divider is clear */
MCG_C6 = 0x0;
/* Set system options dividers
MCG=PLL, core = MCG */
SIM_CLKDIV0 = SIM_CLKDIV0_OUTDIV(0);
/* Set the VCO divider and enable the PLL for 48MHz, LOLIE=0, PLLS=1, CME=0, VDIV=0 */
MCG_C6 = MCG_C6_PLLS_MASK; //VDIV = 0 (x24)
/* Wait for PLL status bit to set */
while (!(MCG_S & MCG_S_PLLST_MASK))
{;}
/* Wait for LOCK bit to set */
while (!(MCG_S & MCG_S_LOCK_MASK))
{;}
/* Now running PBE Mode */
/* 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)
{;}
/* Now running PEE Mode */
SIM_SOPT3 |= SIM_SOPT3_RWE_MASK;
SIM_SOPT1 |= SIM_SOPT1_REGE_MASK;
SIM_SOPT7 |= 0x80;
/* Ensure PLL is selected as USB CLK source */
SIM_CLKDIV1 = 0x00;
}
