void sysclk_init(void)
{
struct pll_config pllcfg;
/* Set a flash wait state depending on the new cpu frequency */
system_init_flash(sysclk_get_cpu_hz());
/* Config system clock setting */
switch (CONFIG_SYSCLK_SOURCE) {
case SYSCLK_SRC_SLCK_RC:
osc_enable(OSC_SLCK_32K_RC);
osc_wait_ready(OSC_SLCK_32K_RC);
pmc_switch_mck_to_sclk(CONFIG_SYSCLK_PRES);
break;
case SYSCLK_SRC_SLCK_XTAL:
osc_enable(OSC_SLCK_32K_XTAL);
osc_wait_ready(OSC_SLCK_32K_XTAL);
pmc_switch_mck_to_sclk(CONFIG_SYSCLK_PRES);
break;
case SYSCLK_SRC_SLCK_BYPASS:
osc_enable(OSC_SLCK_32K_BYPASS);
osc_wait_ready(OSC_SLCK_32K_BYPASS);
pmc_switch_mck_to_sclk(CONFIG_SYSCLK_PRES);
break;
case SYSCLK_SRC_MAINCK_4M_RC:
/* Already running from SYSCLK_SRC_MAINCK_4M_RC */
break;
case SYSCLK_SRC_MAINCK_8M_RC:
osc_enable(OSC_MAINCK_8M_RC);
osc_wait_ready(OSC_MAINCK_8M_RC);
pmc_switch_mck_to_mainck(CONFIG_SYSCLK_PRES);
break;
case SYSCLK_SRC_MAINCK_12M_RC:
osc_enable(OSC_MAINCK_12M_RC);
osc_wait_ready(OSC_MAINCK_12M_RC);
pmc_switch_mck_to_mainck(CONFIG_SYSCLK_PRES);
break;
case SYSCLK_SRC_MAINCK_XTAL:
osc_enable(OSC_MAINCK_XTAL);
osc_wait_ready(OSC_MAINCK_XTAL);
pmc_switch_mck_to_mainck(CONFIG_SYSCLK_PRES);
break;
case SYSCLK_SRC_MAINCK_BYPASS:
osc_enable(OSC_MAINCK_BYPASS);
osc_wait_ready(OSC_MAINCK_BYPASS);
pmc_switch_mck_to_mainck(CONFIG_SYSCLK_PRES);
break;
#ifdef CONFIG_PLL0_SOURCE
case SYSCLK_SRC_PLLACK:
pll_enable_source(CONFIG_PLL0_SOURCE);
pll_config_defaults(&pllcfg, 0);
pll_enable(&pllcfg, 0);
pll_wait_for_lock(0);
pmc_switch_mck_to_pllack(CONFIG_SYSCLK_PRES);
break;
#endif
#ifdef CONFIG_PLL1_SOURCE
case SYSCLK_SRC_PLLBCK:
pll_enable_source(CONFIG_PLL1_SOURCE);
pll_config_defaults(&pllcfg, 1);
pll_enable(&pllcfg, 1);
pll_wait_for_lock(1);
pmc_switch_mck_to_pllbck(CONFIG_SYSCLK_PRES);
break;
#endif
}
/* Update the SystemFrequency variable */
SystemCoreClockUpdate();
#if (defined CONFIG_SYSCLK_DEFAULT_RETURNS_SLOW_OSC)
/* Signal that the internal frequencies are setup */
sysclk_initialized = 1;
#endif
}
void sysclk_init(void)
{
/* Set flash wait state to max in case the below clock switching. */
system_init_flash(CHIP_FREQ_CPU_MAX);
/* Config system clock setting */
if (CONFIG_SYSCLK_SOURCE == SYSCLK_SRC_SLCK_RC) {
osc_enable(OSC_SLCK_32K_RC);
osc_wait_ready(OSC_SLCK_32K_RC);
pmc_switch_mck_to_sclk(CONFIG_SYSCLK_PRES);
}
else if (CONFIG_SYSCLK_SOURCE == SYSCLK_SRC_SLCK_XTAL) {
osc_enable(OSC_SLCK_32K_XTAL);
osc_wait_ready(OSC_SLCK_32K_XTAL);
pmc_switch_mck_to_sclk(CONFIG_SYSCLK_PRES);
}
else if (CONFIG_SYSCLK_SOURCE == SYSCLK_SRC_SLCK_BYPASS) {
osc_enable(OSC_SLCK_32K_BYPASS);
osc_wait_ready(OSC_SLCK_32K_BYPASS);
pmc_switch_mck_to_sclk(CONFIG_SYSCLK_PRES);
}
else if (CONFIG_SYSCLK_SOURCE == SYSCLK_SRC_MAINCK_4M_RC) {
/* Already running from SYSCLK_SRC_MAINCK_4M_RC */
}
else if (CONFIG_SYSCLK_SOURCE == SYSCLK_SRC_MAINCK_8M_RC) {
osc_enable(OSC_MAINCK_8M_RC);
osc_wait_ready(OSC_MAINCK_8M_RC);
pmc_switch_mck_to_mainck(CONFIG_SYSCLK_PRES);
}
else if (CONFIG_SYSCLK_SOURCE == SYSCLK_SRC_MAINCK_12M_RC) {
osc_enable(OSC_MAINCK_12M_RC);
osc_wait_ready(OSC_MAINCK_12M_RC);
pmc_switch_mck_to_mainck(CONFIG_SYSCLK_PRES);
}
else if (CONFIG_SYSCLK_SOURCE == SYSCLK_SRC_MAINCK_XTAL) {
osc_enable(OSC_MAINCK_XTAL);
osc_wait_ready(OSC_MAINCK_XTAL);
pmc_switch_mck_to_mainck(CONFIG_SYSCLK_PRES);
}
else if (CONFIG_SYSCLK_SOURCE == SYSCLK_SRC_MAINCK_BYPASS) {
osc_enable(OSC_MAINCK_BYPASS);
osc_wait_ready(OSC_MAINCK_BYPASS);
pmc_switch_mck_to_mainck(CONFIG_SYSCLK_PRES);
}
#ifdef CONFIG_PLL0_SOURCE
else if (CONFIG_SYSCLK_SOURCE == SYSCLK_SRC_PLLACK) {
struct pll_config pllcfg;
pll_enable_source(CONFIG_PLL0_SOURCE);
pll_config_defaults(&pllcfg, 0);
pll_enable(&pllcfg, 0);
pll_wait_for_lock(0);
pmc_switch_mck_to_pllack(CONFIG_SYSCLK_PRES);
}
#endif
#ifdef CONFIG_PLL1_SOURCE
else if (CONFIG_SYSCLK_SOURCE == SYSCLK_SRC_PLLBCK) {
struct pll_config pllcfg;
pll_enable_source(CONFIG_PLL1_SOURCE);
pll_config_defaults(&pllcfg, 1);
pll_enable(&pllcfg, 1);
pll_wait_for_lock(1);
pmc_switch_mck_to_pllbck(CONFIG_SYSCLK_PRES);
}
#endif
/* Update the SystemFrequency variable */
SystemCoreClockUpdate();
/* Set a flash wait state depending on the new cpu frequency */
system_init_flash(sysclk_get_cpu_hz());
#if (defined CONFIG_SYSCLK_DEFAULT_RETURNS_SLOW_OSC)
/* Signal that the internal frequencies are setup */
sysclk_initialized = 1;
#endif
#ifdef CONFIG_CPCLK_ENABLE
/* Enable coprocessor clock */
sysclk_configure_cpclk();
#endif
}
/**
* \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) {
}
}
