/**
* \brief Set default clock (MCK = 24MHz).
*/
static void set_default_working_clock(void)
{
#if (SAMG)
/* Switch MCK to slow clock */
pmc_switch_mck_to_sclk(PMC_MCKR_PRES_CLK_1);
/*
* Configure PLL and switch clock.
* MCK = XTAL * (PLL_DEFAULT_MUL+1) / PLL_DEFAULT_DIV / MCK_DEFAULT_DIV
* = 24 MHz
*/
example_switch_clock(PLL_DEFAULT_MUL, PLL_COUNT, PLL_DEFAULT_DIV,
MCK_DEFAULT_DIV);
#else
/* Switch MCK to slow clock */
pmc_switch_mck_to_sclk(PMC_MCKR_PRES_CLK_1);
/* Switch mainck to external xtal */
pmc_switch_mainck_to_xtal(0, BOARD_OSC_STARTUP_US);
/*
* Configure PLL and switch clock.
* MCK = XTAL * (PLL_DEFAULT_MUL+1) / PLL_DEFAULT_DIV / MCK_DEFAULT_DIV
* = 24 MHz
*/
example_switch_clock(PLL_DEFAULT_MUL, PLL_COUNT, PLL_DEFAULT_DIV,
MCK_DEFAULT_DIV);
/* Disable unused clock to save power */
pmc_osc_disable_fastrc();
#endif
/* Save current clock */
g_ul_current_mck = 24000000; /* 24MHz */
}
/**
* Restore clock settings
*/
__always_inline static void pmc_restore_clock_setting(
uint32_t osc_setting,
uint32_t pll0_setting,
uint32_t pll1_setting,
uint32_t mck_setting)
{
uint32_t mckr;
uint32_t pll_sr = 0;
/* Switch MCK to slow clock */
pmc_switch_mck_to_sclk(PMC_MCKR_PRES_CLK_1);
/* Switch mainck to external xtal */
if (CKGR_MOR_MOSCXTBY == (osc_setting & CKGR_MOR_MOSCXTBY)) {
/* Bypass mode */
pmc_switch_mainck_to_xtal(PMC_OSC_BYPASS,
pmc_us_to_moscxtst(BOARD_OSC_STARTUP_US,
CHIP_FREQ_SLCK_RC));
pmc_osc_disable_fastrc();
} else if (CKGR_MOR_MOSCXTEN == (osc_setting & CKGR_MOR_MOSCXTEN)) {
/* External XTAL */
pmc_switch_mainck_to_xtal(PMC_OSC_XTAL,
pmc_us_to_moscxtst(BOARD_OSC_STARTUP_US,
CHIP_FREQ_SLCK_RC));
pmc_osc_disable_fastrc();
}
if (pll0_setting & CKGR_PLLAR_MULA_Msk) {
PMC->CKGR_PLLAR = CKGR_PLLAR_ONE | pll0_setting;
pll_sr |= PMC_SR_LOCKA;
}
#if (SAM3S || SAM4S)
if (pll1_setting & CKGR_PLLBR_MULB_Msk) {
PMC->CKGR_PLLBR = pll1_setting;
pll_sr |= PMC_SR_LOCKB;
}
#elif (SAM3U || SAM3XA)
if (pll1_setting & CKGR_UCKR_UPLLEN) {
PMC->CKGR_UCKR = pll1_setting;
pll_sr |= PMC_SR_LOCKU;
}
#else
UNUSED(pll1_setting);
#endif
/* Wait MCK source ready */
switch(mck_setting & PMC_MCKR_CSS_Msk) {
case PMC_MCKR_CSS_PLLA_CLK:
while (!(PMC->PMC_SR & PMC_SR_LOCKA));
break;
#if (SAM3S || SAM4S)
case PMC_MCKR_CSS_PLLB_CLK:
while (!(PMC->PMC_SR & PMC_SR_LOCKB));
break;
#elif (SAM3U || SAM3XA)
case PMC_MCKR_CSS_UPLL_CLK:
while (!(PMC->PMC_SR & PMC_SR_LOCKU));
break;
#endif
}
/* Switch to faster clock */
mckr = PMC->PMC_MCKR;
/* Set PRES */
PMC->PMC_MCKR = (mckr & ~PMC_MCKR_PRES_Msk)
| (mck_setting & PMC_MCKR_PRES_Msk);
while (!(PMC->PMC_SR & PMC_SR_MCKRDY));
/* Set CSS and others */
PMC->PMC_MCKR = mck_setting;
while (!(PMC->PMC_SR & PMC_SR_MCKRDY));
/* Waiting all restored PLLs ready */
while (!(PMC->PMC_SR & pll_sr));
}
/**
* \brief Change clock configuration.
*
* \param p_uc_str Hint string to be output on console before changing clock.
*/
static void user_change_clock(uint8_t *p_uc_str)
{
uint8_t uc_key;
uint32_t ul_id;
/* Print menu */
puts(CLOCK_LIST_MENU);
while (uart_read(CONSOLE_UART, &uc_key)) {
}
printf("Select option is: %c\n\r\n\r", uc_key);
if (p_uc_str) {
puts((char const *)p_uc_str);
}
while (!uart_is_tx_empty(CONSOLE_UART)) {
}
if ((uc_key >= MIN_CLOCK_FAST_RC_ITEM) &&
(uc_key <= MAX_CLOCK_FAST_RC_ITEM)) {
ul_id = uc_key - MIN_CLOCK_FAST_RC_ITEM;
/* Save current clock */
g_ul_current_mck = g_fastrc_clock_list[ul_id][0];
/* Switch MCK to Slow clock */
pmc_switch_mck_to_sclk(PMC_MCKR_PRES_CLK_1);
/* Switch mainck to fast RC */
pmc_osc_enable_fastrc(CKGR_MOR_MOSCRCF_8_MHz);
pmc_switch_mainck_to_fastrc(g_fastrc_clock_list[ul_id][1]);
/* Switch MCK to mainck */
pmc_switch_mck_to_mainck(g_fastrc_clock_list[ul_id][2]);
/* Disable unused clock to save power */
pmc_osc_disable_xtal(0);
example_disable_pll();
} else if ((uc_key >= MIN_CLOCK_PLL_ITEM) &&
(uc_key <= MAX_CLOCK_PLL_ITEM)) {
ul_id = uc_key - MIN_CLOCK_PLL_ITEM;
/* Save current clock */
g_ul_current_mck = g_pll_clock_list[ul_id][0];
#if (SAMG)
/* Switch MCK to main clock */
pmc_switch_mck_to_mainck(PMC_MCKR_PRES_CLK_1);
#else
/* Switch MCK to slow clock */
pmc_switch_mck_to_sclk(PMC_MCKR_PRES_CLK_1);
/* Switch mainck to external xtal */
pmc_switch_mainck_to_xtal(0, BOARD_OSC_STARTUP_US);
#endif
/* Configure PLL and switch clock */
example_switch_clock(g_pll_clock_list[ul_id][1], PLL_COUNT,
g_pll_clock_list[ul_id][2], g_pll_clock_list[ul_id][3]);
#if (!SAMG)
/* Disable unused clock to save power */
pmc_osc_disable_fastrc();
#endif
} else {
puts("Clock is not changed.\r");
}
}
/**
* \brief Application entry point for pmc_clock switch example.
*
* \return Unused (ANSI-C compatibility).
*/
int main(void)
{
/* Initialize the SAM system */
sysclk_init();
board_init();
/* Initialize the console uart */
configure_console();
/* Output example information */
puts(STRING_HEADER);
/* Configure PCK */
ioport_set_pin_mode(GCLK_PIN, GCLK_PIN_MUX);
ioport_disable_pin(GCLK_PIN);
/* Configure the push button */
configure_buttons();
puts("-I- Press Button "BUTTON_NAME" to continue.\r\n");
/* Wait for UART transmit done */
while (!uart_is_tx_empty(CONF_UART)) {
};
for (gs_uc_wait_button = 1; gs_uc_wait_button;) {
}
puts("\n\r-I- Switch 8Mhz fast RC oscillator to be the source of the main clock \n\r"
"-I- The master clock is main clock divided by 2\n\r"
"-I- From now on, the UART baud rate is 2400bps. So please change the terminal setting before the next clock switch\r\n"
"-I- Press Button "BUTTON_NAME" to switch next clock configuration... \r\n");
/* Wait for UART transmit done */
while (!uart_is_tx_empty(CONF_UART)) {
};
/* First switch to slow clock */
pmc_switch_mck_to_sclk(PMC_MCKR_PRES_CLK_1);
#if (SAM3S || SAM4S || SAM4C)
/* Then cut the PLL B */
pmc_disable_pllbck();
#endif
/* Switch the mainck clock to the Fast RC, parameter '1' stands for 8Mhz */
pmc_switch_mainck_to_fastrc(CKGR_MOR_MOSCRCF_8_MHz);
/* And finalize by switching to Fast RC */
pmc_switch_mck_to_mainck(PMC_MCKR_PRES_CLK_2);
/* The clock source for the UART is the PCK, so the uart needs re-configuration */
config_uart_and_pck(PMC_PCK_CSS_MAIN_CLK, PMC_PCK_PRES_CLK_2,
(CHIP_FREQ_MAINCK_RC_8MHZ / 2));
for (gs_uc_wait_button = 1; gs_uc_wait_button;) {
}
puts("\n\r-I- Switch the XTAL 32K crystal oscillator to be the source of the slow clock\n\r"
"-I- The master clock is slow clock\n\r"
"-I- Press Button "BUTTON_NAME" to switch next clock configuration after it has been measured.\r\n");
/* Wait for UART transmit done */
while (!uart_is_tx_empty(CONF_UART)) {
};
/* Enable the External 32K oscillator */
pmc_switch_sclk_to_32kxtal(PMC_OSC_XTAL);
/* If a new value for CSS field corresponds to Main Clock or Slow Clock,
* program the CSS field first.
*/
pmc_switch_mck_to_sclk(PMC_MCKR_PRES_CLK_1);
/* The clock source for the UART is the PCK, so the uart needs
*re-configuration.
*/
config_uart_and_pck(PMC_PCK_CSS_SLOW_CLK, PMC_PCK_PRES_CLK_1,
BOARD_FREQ_SLCK_XTAL);
for (gs_uc_wait_button = 1; gs_uc_wait_button;) {
}
/* Switch the mainck to the Fast RC, parameter '2' stands for 12Mhz */
pmc_switch_mainck_to_fastrc(CKGR_MOR_MOSCRCF_12_MHz);
/* If a new value for CSS field corresponds to Main Clock or Slow Clock,
* program the CSS field first.
*/
pmc_switch_mck_to_mainck(PMC_PCK_PRES_CLK_1);
/* The clock source for the UART is the PCK, so the uart needs
* re-configuration.
*/
config_uart_and_pck(PMC_PCK_CSS_MAIN_CLK, PMC_PCK_PRES_CLK_1,
CHIP_FREQ_MAINCK_RC_12MHZ);
puts("\n\r-I- Switch 12Mhz fast RC oscillator to be the source of the main clock\n\r"
"-I- The master clock is the main clock\n\r"
"-I- Press Button "BUTTON_NAME" to switch next clock configuration after it has been measured.\r\n");
for (gs_uc_wait_button = 1; gs_uc_wait_button;) {
}
#if SAM4C
puts("-I- Switch to 8.192Mhz PLLA clock as the source of the master clock \n\r"
"-I- The master clock is PLLA clock divided by 2 \n\r"
"-I- Press Button "BUTTON_NAME" to switch next clock configuration... \r\n");
/* Wait for UART transmit done */
while (!uart_is_tx_empty(CONF_UART)) {
};
/* Enable the PLLA clock, the mainck equals 32.768K * 250 = 8.192Mhz */
pmc_enable_pllack((250 - 1), 0x3f, 1);
#else
puts("-I- Switch to 128Mhz PLLA clock as the source of the master clock \n\r"
"-I- The master clock is PLLA clock divided by 2 \n\r"
"-I- Press Button "BUTTON_NAME" to switch next clock configuration... \r\n");
/* Wait for UART transmit done */
while (!uart_is_tx_empty(CONF_UART)) {
};
/* Enable the PLLA clock, the mainck equals 12Mhz * (32-1+1) / 3 = 128Mhz */
pmc_enable_pllack((32 - 1), 0x3f, 3);
#endif
/* If a new value for CSS field corresponds to PLL Clock, Program the PRES
* field first.
*/
pmc_switch_mck_to_mainck(PMC_MCKR_PRES_CLK_2);
/* Delay for a while */
/* Wait for UART transmit done */
while (!uart_is_tx_empty(CONF_UART)) {
};
/* Then program the CSS field. */
pmc_switch_mck_to_pllack(PMC_MCKR_PRES_CLK_2);
/* The clock source for the UART is the PCK, so the uart needs
* re-configuration
*/
config_uart_and_pck(PMC_PCK_CSS_PLLA_CLK, PMC_PCK_PRES_CLK_2,
PMC_CLOCK_SWITCHING_EXAMPLE_FIXED_PLLA/2);
for (gs_uc_wait_button = 1; gs_uc_wait_button;) {
}
puts("\n\r-I- Switch the XTAL 32K crystal oscillator to be the source of the slow clock\n\r"
"-I- The master clock is slow clock\n\r"
"-I- Press Button "BUTTON_NAME" to switch next clock configuration...\r\n");
/* Wait for UART transmit done */
while (!uart_is_tx_empty(CONF_UART)) {
};
/* Switch slow clck to extern 32k xtal */
pmc_switch_sclk_to_32kxtal(PMC_OSC_XTAL);
/* Delay for a while to make sure the clock is stable */
/* Wait for UART transmit done */
while (!uart_is_tx_empty(CONF_UART)) {
};
/* If a new value for CSS field corresponds to Main Clock or Slow Clock,
* program the CSS field first.
*/
pmc_switch_mck_to_mainck(PMC_MCKR_PRES_CLK_2);
/* Switch the mck to sclk but keep the PRES field same */
pmc_switch_mck_to_sclk(PMC_MCKR_PRES_CLK_2);
/* Then program the PRES field. */
pmc_switch_mck_to_sclk(PMC_MCKR_PRES_CLK_1);
/* The clock source for the UART is the PCK, so the uart needs
* re-configuration
*/
config_uart_and_pck(PMC_PCK_CSS_SLOW_CLK, PMC_PCK_PRES_CLK_1,
BOARD_FREQ_SLCK_XTAL);
for (gs_uc_wait_button = 1; gs_uc_wait_button;) {
}
/* Switch mainck to external xtal */
pmc_switch_mainck_to_xtal(0, BOARD_OSC_STARTUP_US);
/* If a new value for CSS field corresponds to Main Clock or Slow Clock,
* program the CSS field first.
*/
pmc_switch_mck_to_mainck(PMC_MCKR_PRES_CLK_1);
/* Then program the PRES field. */
pmc_switch_mck_to_mainck(PMC_MCKR_PRES_CLK_16);
/* The clock source for the UART is the PCK, so the uart needs
* re-configuration.
*/
config_uart_and_pck(PMC_PCK_CSS_MAIN_CLK, PMC_PCK_PRES_CLK_16,
(BOARD_FREQ_MAINCK_XTAL / 16));
#if SAM4C
puts("\n\r-I- Switch the external 8MHz crystal oscillator to be the source of the main clock\n\r"
"-I- The master clock is main clock divided by 16\n\r"
"-I- Press Button "BUTTON_NAME" to switch next clock configuration...\r\n");
#else
puts("\n\r-I- Switch the external 12MHz crystal oscillator to be the source of the main clock\n\r"
"-I- The master clock is main clock divided by 16\n\r"
"-I- Press Button "BUTTON_NAME" to switch next clock configuration...\r\n");
#endif
#if (SAM3S || SAM4S || SAM4C)
for (gs_uc_wait_button = 1; gs_uc_wait_button;) {
}
puts("-I- Switch to 96Mhz PLLB clock as the source of the master clock\n\r"
"-I- The master clock is PLLB clock divided by 2 \r");
/* Wait for UART transmit done */
while (!uart_is_tx_empty(CONF_UART)) {
};
#if SAM4C
/* Enable the PLLB clock, the mainck equals (8Mhz * (11+1) / 1) = 96Mhz
* with the initialize counter be 0x3f
*/
pmc_enable_pllbck(11, 0x3f, 1);
#else
/* Enable the PLLB clock, the mainck equals (12Mhz * (7+1) / 1) = 96Mhz
* with the initialize counter be 0x3f
*/
pmc_enable_pllbck(7, 0x3f, 1);
#endif
/* If a new value for CSS field corresponds to PLL Clock, Program the PRES
* field first.
*/
pmc_switch_mck_to_mainck(PMC_MCKR_PRES_CLK_2);
/* Then program the CSS field. */
pmc_switch_mck_to_pllbck(PMC_MCKR_PRES_CLK_2);
/* The clock source for the UART is the PCK, so the uart needs
* re-configuration.
*/
#if SAM4C
config_uart_and_pck(PMC_PCK_CSS_PLLB_CLK, PMC_PCK_PRES_CLK_2,
(BOARD_FREQ_MAINCK_XTAL * 12 / 2));
#else
config_uart_and_pck(PMC_PCK_CSS_PLLB_CLK, PMC_PCK_PRES_CLK_2,
(BOARD_FREQ_MAINCK_XTAL * 8 / 2));
#endif
puts("-I- Press Button "BUTTON_NAME" to switch next clock configuration...\r\n");
#endif
for (gs_uc_wait_button = 1; gs_uc_wait_button;) {
}
puts("\r\n\r\n-I- Done.\r\n");
/* Wait for UART transmit done */
while (!uart_is_tx_empty(CONF_UART)) {
};
while (1) {
}
}
