* SOFTWARE.
*/
-#include "mk20dx128.h"
+#include "kinetis.h"
extern unsigned long _stext;
extern unsigned long _estack;
//extern void __init_array_start(void);
//extern void __init_array_end(void);
+
+
+
extern int main (void);
void ResetHandler(void);
void _init_Teensyduino_internal_(void);
void porte_isr(void) __attribute__ ((weak, alias("unused_isr")));
void software_isr(void) __attribute__ ((weak, alias("unused_isr")));
+#if defined(__MK20DX128__)
+__attribute__ ((section(".dmabuffers"), used, aligned(256)))
+#else
+__attribute__ ((section(".dmabuffers"), used, aligned(512)))
+#endif
+void (* _VectorsRam[NVIC_NUM_INTERRUPTS+16])(void);
-// TODO: create AVR-stype ISR() macro, with default linkage to undefined handler
-//
__attribute__ ((section(".vectors"), used))
-void (* const gVectors[])(void) =
+void (* const _VectorsFlash[NVIC_NUM_INTERRUPTS+16])(void) =
{
(void (*)(void))((unsigned long)&_estack), // 0 ARM: Initial Stack Pointer
ResetHandler, // 1 ARM: Initial Program Counter
uint32_t *src = &_etext;
uint32_t *dest = &_sdata;
unsigned int i;
+#if F_CPU <= 2000000
+ volatile int n;
+#endif
WDOG_UNLOCK = WDOG_UNLOCK_SEQ1;
WDOG_UNLOCK = WDOG_UNLOCK_SEQ2;
- asm volatile ("nop");
- asm volatile ("nop");
+ __asm__ volatile ("nop");
+ __asm__ volatile ("nop");
// programs using the watchdog timer or needing to initialize hardware as
// early as possible can implement startup_early_hook()
startup_early_hook();
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;
#endif
-
// if the RTC oscillator isn't enabled, get it started early
if (!(RTC_CR & RTC_CR_OSCE)) {
RTC_SR = 0;
// release I/O pins hold, if we woke up from VLLS mode
if (PMC_REGSC & PMC_REGSC_ACKISO) PMC_REGSC |= PMC_REGSC_ACKISO;
+ // since this is a write once register, make it visible to all F_CPU's
+ // so we can into other sleep modes in the future at any speed
+ SMC_PMPROT = SMC_PMPROT_AVLP | SMC_PMPROT_ALLS | SMC_PMPROT_AVLLS;
+
// 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
// default all interrupts to medium priority level
+ for (i=0; i < NVIC_NUM_INTERRUPTS + 16; i++) _VectorsRam[i] = _VectorsFlash[i];
for (i=0; i < NVIC_NUM_INTERRUPTS; i++) NVIC_SET_PRIORITY(i, 128);
-
- // start in FEI mode
+ SCB_VTOR = (uint32_t)_VectorsRam; // use vector table in RAM
+
+ // hardware always starts in FEI mode
+ // C1[CLKS] bits are written to 00
+ // C1[IREFS] bit is written to 1
+ // C6[PLLS] bit is written to 0
+// MCG_SC[FCDIV] defaults to divide by two for internal ref clock
+// I tried changing MSG_SC to divide by 1, it didn't work for me
+#if F_CPU <= 2000000
+ // use the internal oscillator
+ MCG_C1 = MCG_C1_CLKS(1) | MCG_C1_IREFS;
+ // wait for MCGOUT to use oscillator
+ while ((MCG_S & MCG_S_CLKST_MASK) != MCG_S_CLKST(1)) ;
+ for (n=0; n<10; n++) ; // TODO: why do we get 2 mA extra without this delay?
+ MCG_C2 = MCG_C2_IRCS;
+ while (!(MCG_S & MCG_S_IRCST)) ;
+ // now in FBI mode:
+ // C1[CLKS] bits are written to 01
+ // C1[IREFS] bit is written to 1
+ // C6[PLLS] is written to 0
+ // C2[LP] is written to 0
+ MCG_C2 = MCG_C2_IRCS | MCG_C2_LP;
+ // now in BLPI mode:
+ // C1[CLKS] bits are written to 01
+ // C1[IREFS] bit is written to 1
+ // C6[PLLS] bit is written to 0
+ // C2[LP] bit is written to 1
+#else
// enable capacitors for crystal
OSC0_CR = OSC_SC8P | OSC_SC2P;
// enable osc, 8-32 MHz range, low power mode
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);
+ // now in FBE mode
+ // C1[CLKS] bits are written to 10
+ // C1[IREFS] bit is written to 0
+ // C1[FRDIV] must be written to divide xtal to 31.25-39 kHz
+ // C6[PLLS] bit is written to 0
+ // C2[LP] is written to 0
+ #if F_CPU <= 16000000
+ // if the crystal is fast enough, use it directly (no FLL or PLL)
+ MCG_C2 = MCG_C2_RANGE0(2) | MCG_C2_EREFS | MCG_C2_LP;
+ // BLPE mode:
+ // C1[CLKS] bits are written to 10
+ // C1[IREFS] bit is written to 0
+ // C2[LP] bit is written to 1
+ #else
+ // if we need faster than the crystal, turn on the PLL
+ #if F_CPU == 72000000
+ MCG_C5 = MCG_C5_PRDIV0(5); // config PLL input for 16 MHz Crystal / 6 = 2.667 Hz
+ #else
+ MCG_C5 = MCG_C5_PRDIV0(3); // config PLL input for 16 MHz Crystal / 4 = 4 MHz
+ #endif
+ #if F_CPU == 168000000
+ MCG_C6 = MCG_C6_PLLS | MCG_C6_VDIV0(18); // config PLL for 168 MHz output
+ #elif F_CPU == 144000000
+ MCG_C6 = MCG_C6_PLLS | MCG_C6_VDIV0(12); // config PLL for 144 MHz output
+ #elif F_CPU == 120000000
+ MCG_C6 = MCG_C6_PLLS | MCG_C6_VDIV0(6); // config PLL for 120 MHz output
+ #elif F_CPU == 72000000
+ MCG_C6 = MCG_C6_PLLS | MCG_C6_VDIV0(3); // config PLL for 72 MHz output
+ #else
+ MCG_C6 = MCG_C6_PLLS | MCG_C6_VDIV0(0); // config PLL for 96 MHz output
+ #endif
// 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
+ #endif
+#endif
+
+ // now program the clock dividers
+#if F_CPU == 168000000
+ // config divisors: 168 MHz core, 56 MHz bus, 33.6 MHz flash, USB = 168 * 2 / 7
+ SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0) | SIM_CLKDIV1_OUTDIV2(2) | SIM_CLKDIV1_OUTDIV4(4);
+ SIM_CLKDIV2 = SIM_CLKDIV2_USBDIV(6) | SIM_CLKDIV2_USBFRAC;
+#elif F_CPU == 144000000
+ // config divisors: 144 MHz core, 48 MHz bus, 28.8 MHz flash, USB = 144 / 3
+ SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0) | SIM_CLKDIV1_OUTDIV2(2) | SIM_CLKDIV1_OUTDIV4(4);
+ SIM_CLKDIV2 = SIM_CLKDIV2_USBDIV(2);
+#elif F_CPU == 120000000
+ // config divisors: 120 MHz core, 60 MHz bus, 24 MHz flash, USB = 128 * 2 / 5
+ SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0) | SIM_CLKDIV1_OUTDIV2(1) | SIM_CLKDIV1_OUTDIV4(4);
+ SIM_CLKDIV2 = SIM_CLKDIV2_USBDIV(4) | SIM_CLKDIV2_USBFRAC;
+#elif F_CPU == 96000000
+ // config divisors: 96 MHz core, 48 MHz bus, 24 MHz flash, USB = 96 / 2
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0) | SIM_CLKDIV1_OUTDIV2(1) | SIM_CLKDIV1_OUTDIV4(3);
+ SIM_CLKDIV2 = SIM_CLKDIV2_USBDIV(1);
+#elif F_CPU == 72000000
+ // config divisors: 72 MHz core, 36 MHz bus, 24 MHz flash, USB = 72 * 2 / 3
+ SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0) | SIM_CLKDIV1_OUTDIV2(1) | SIM_CLKDIV1_OUTDIV4(2);
+ SIM_CLKDIV2 = SIM_CLKDIV2_USBDIV(2) | SIM_CLKDIV2_USBFRAC;
#elif F_CPU == 48000000
- // config divisors: 48 MHz core, 48 MHz bus, 24 MHz flash
+ // config divisors: 48 MHz core, 48 MHz bus, 24 MHz flash, USB = 96 / 2
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(1) | SIM_CLKDIV1_OUTDIV2(1) | SIM_CLKDIV1_OUTDIV4(3);
+ SIM_CLKDIV2 = SIM_CLKDIV2_USBDIV(1);
#elif F_CPU == 24000000
- // config divisors: 24 MHz core, 24 MHz bus, 24 MHz flash
+ // config divisors: 24 MHz core, 24 MHz bus, 24 MHz flash, USB = 96 / 2
+ SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(3) | SIM_CLKDIV1_OUTDIV2(3) | SIM_CLKDIV1_OUTDIV4(3);
+ SIM_CLKDIV2 = SIM_CLKDIV2_USBDIV(1);
+#elif F_CPU == 16000000
+ // config divisors: 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
+ // config divisors: 8 MHz core, 8 MHz bus, 8 MHz flash
+ SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(1) | SIM_CLKDIV1_OUTDIV2(1) | SIM_CLKDIV1_OUTDIV4(1);
+#elif F_CPU == 4000000
+ // config divisors: 4 MHz core, 4 MHz bus, 2 MHz flash
+ // since we are running from external clock 16MHz
+ // fix outdiv too -> cpu 16/4, bus 16/4, flash 16/4
+ // here we can go into vlpr?
+ // config divisors: 4 MHz core, 4 MHz bus, 4 MHz flash
SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(3) | SIM_CLKDIV1_OUTDIV2(3) | SIM_CLKDIV1_OUTDIV4(3);
+#elif F_CPU == 2000000
+ // since we are running from the fast internal reference clock 4MHz
+ // but is divided down by 2 so we actually have a 2MHz, MCG_SC[FCDIV] default is 2
+ // fix outdiv -> cpu 2/1, bus 2/1, flash 2/2
+ // config divisors: 2 MHz core, 2 MHz bus, 1 MHz flash
+ SIM_CLKDIV1 = SIM_CLKDIV1_OUTDIV1(0) | SIM_CLKDIV1_OUTDIV2(0) | SIM_CLKDIV1_OUTDIV4(1);
#else
-#error "Error, F_CPU must be 96000000, 48000000, or 24000000"
+#error "Error, F_CPU must be 168, 144, 120, 96, 72, 48, 24, 16, 8, 4, or 2 MHz"
#endif
+
+#if F_CPU > 16000000
// 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);
+#else
+ SIM_SOPT2 = SIM_SOPT2_TRACECLKSEL | SIM_SOPT2_CLKOUTSEL(3);
+#endif
+
+#if F_CPU <= 2000000
+ // since we are not going into "stop mode" i removed it
+ SMC_PMCTRL = SMC_PMCTRL_RUNM(2); // VLPR mode :-)
+#endif
// initialize the SysTick counter
SYST_RVR = (F_CPU / 1000) - 1;
__enable_irq();
_init_Teensyduino_internal_();
- if (RTC_SR & RTC_SR_TIF) rtc_set(TIME_T);
+ if (RTC_SR & RTC_SR_TIF) {
+ // TODO: this should probably set the time more agressively, if
+ // we could reliably detect the first reboot after programming.
+ rtc_set(TIME_T);
+ }
__libc_init_array();
-/*
- for (ptr = &__init_array_start; ptr < &__init_array_end; ptr++) {
- (*ptr)();
- }
-*/
startup_late_hook();
main();
while (1) ;
}
-// TODO: is this needed for c++ and where does it come from?
-/*
-void _init(void)
-{
-}
-*/
-
char *__brkval = (char *)&_ebss;
void * _sbrk(int incr)
{
- //static char *heap_end = (char *)&_ebss;
- //char *prev = heap_end;
- //heap_end += incr;
-
char *prev = __brkval;
__brkval += incr;
return prev;
return 0;
}
-/* moved to Print.cpp, to support Print::printf()
-__attribute__((weak))
-int _write(int file, char *ptr, int len)
-{
- return 0;
-}
-*/
-
__attribute__((weak))
int _close(int fd)
{
// full algorithm in ARM DDI0403D, page B1-639
// this isn't quite complete, but hopefully good enough
- asm volatile("mrs %0, faultmask\n" : "=r" (faultmask)::);
+ __asm__ volatile("mrs %0, faultmask\n" : "=r" (faultmask)::);
if (faultmask) return -1;
- asm volatile("mrs %0, primask\n" : "=r" (primask)::);
+ __asm__ volatile("mrs %0, primask\n" : "=r" (primask)::);
if (primask) return 0;
- asm volatile("mrs %0, ipsr\n" : "=r" (ipsr)::);
+ __asm__ volatile("mrs %0, ipsr\n" : "=r" (ipsr)::);
if (ipsr) {
if (ipsr < 16) priority = 0; // could be non-zero
else priority = NVIC_GET_PRIORITY(ipsr - 16);
}
- asm volatile("mrs %0, basepri\n" : "=r" (basepri)::);
+ __asm__ volatile("mrs %0, basepri\n" : "=r" (basepri)::);
if (basepri > 0 && basepri < priority) priority = basepri;
return priority;
}