コード例 #1
0
ファイル: clock_sam3.c プロジェクト: 7h0ma5/kiss-avraprs
void clock_init(void)
{
	uint32_t timeout;

	/* Disable watchdog */
	WDT_MR = BV(WDT_WDDIS);

	/* Set wait states for flash access, needed for higher CPU clock rates */
	EEFC0_FMR = EEFC_FMR_FWS(3);
#ifdef EEFC1_FMR
	EEFC1_FMR = EEFC_FMR_FWS(3);
#endif

	// Initialize main oscillator
	if (!(CKGR_MOR & BV(CKGR_MOR_MOSCSEL)))
	{
		CKGR_MOR = CKGR_MOR_KEY(0x37) | CKGR_MOR_MOSCXTST(0x8)
			| BV(CKGR_MOR_MOSCRCEN) | BV(CKGR_MOR_MOSCXTEN);
		timeout = CLOCK_TIMEOUT;
		while (!(PMC_SR & BV(PMC_SR_MOSCXTS)) && --timeout);
	}

	// Switch to external oscillator
	CKGR_MOR = CKGR_MOR_KEY(0x37) | CKGR_MOR_MOSCXTST(0x8)
		| BV(CKGR_MOR_MOSCRCEN) | BV(CKGR_MOR_MOSCXTEN) | BV(CKGR_MOR_MOSCSEL);
	timeout = CLOCK_TIMEOUT;
	while (!(PMC_SR & BV(PMC_SR_MOSCXTS)) && --timeout);

	// Initialize and enable PLL clock
	CKGR_PLLR = evaluate_pll() | BV(CKGR_PLLR_STUCKTO1) | CKGR_PLLR_PLLCOUNT(0x2);
	timeout = CLOCK_TIMEOUT;
	while (!(PMC_SR & BV(PMC_SR_LOCK)) && --timeout);

	PMC_MCKR = PMC_MCKR_CSS_MAIN_CLK;
	timeout = CLOCK_TIMEOUT;
	while (!(PMC_SR & BV(PMC_SR_MCKRDY)) && --timeout);

	PMC_MCKR = PMC_MCKR_CSS_PLL_CLK;
	timeout = CLOCK_TIMEOUT;
	while (!(PMC_SR & BV(PMC_SR_MCKRDY)) && --timeout);

	/* Enable clock on PIO for inputs */
	// TODO: move this in gpio_init() for better power management?
	pmc_periphEnable(PIOA_ID);
	pmc_periphEnable(PIOB_ID);
	pmc_periphEnable(PIOC_ID);
#ifdef PIOF_ID
	pmc_periphEnable(PIOD_ID);
	pmc_periphEnable(PIOE_ID);
	pmc_periphEnable(PIOF_ID);
#endif
}
コード例 #2
0
ファイル: clock_sam3.c プロジェクト: derkling/adcontrol
void clock_init(void)
{
	uint32_t timeout;

	/* Disable watchdog */
	WDT_MR = BV(WDT_WDDIS);

	/* Set 4 wait states for flash access, needed for higher CPU clock rates */
	EEFC_FMR = EEFC_FMR_FWS(3);

	// Select external slow clock
	if (!(SUPC_SR & BV(SUPC_SR_OSCSEL)))
	{
		SUPC_CR = BV(SUPC_CR_XTALSEL) | SUPC_CR_KEY(0xA5);
		while (!(SUPC_SR & BV(SUPC_SR_OSCSEL)));
	}

	// Initialize main oscillator
	if (!(CKGR_MOR & BV(CKGR_MOR_MOSCSEL)))
	{
		CKGR_MOR = CKGR_MOR_KEY(0x37) | BOARD_OSC_COUNT | BV(CKGR_MOR_MOSCRCEN) | BV(CKGR_MOR_MOSCXTEN);
		timeout = CLOCK_TIMEOUT;
		while (!(PMC_SR & BV(PMC_SR_MOSCXTS)) && --timeout);
	}

	// Switch to external oscillator
	CKGR_MOR = CKGR_MOR_KEY(0x37) | BOARD_OSC_COUNT | BV(CKGR_MOR_MOSCRCEN) | BV(CKGR_MOR_MOSCXTEN) | BV(CKGR_MOR_MOSCSEL);
	timeout = CLOCK_TIMEOUT;
	while (!(PMC_SR & BV(PMC_SR_MOSCSELS)) && --timeout);

	PMC_MCKR = (PMC_MCKR & ~(uint32_t)PMC_MCKR_CSS_MASK) | PMC_MCKR_CSS_MAIN_CLK;
	timeout = CLOCK_TIMEOUT;
	while (!(PMC_SR & BV(PMC_SR_MCKRDY)) && --timeout);

	// Initialize and enable PLL clock
	CKGR_PLLR = evaluate_pll() | BV(CKGR_PLLR_STUCKTO1) | CKGR_PLLR_PLLCOUNT(0x1);
	timeout = CLOCK_TIMEOUT;
	while (!(PMC_SR & BV(PMC_SR_LOCK)) && --timeout);

	PMC_MCKR = PMC_MCKR_CSS_MAIN_CLK;
	timeout = CLOCK_TIMEOUT;
	while (!(PMC_SR & BV(PMC_SR_MCKRDY)) && --timeout);

	PMC_MCKR = PMC_MCKR_CSS_PLL_CLK;
	timeout = CLOCK_TIMEOUT;
	while (!(PMC_SR & BV(PMC_SR_MCKRDY)) && --timeout);

	/* Enable clock on PIO for inputs */
	PMC_PCER = BV(PIOA_ID) | BV(PIOB_ID) | BV(PIOC_ID);
}