跑一下SAM4N例程(四)：时钟1

#ifndef CONF_CLOCK_H_INCLUDED

#define CONF_CLOCK_H_INCLUDED



// ===== System Clock (MCK) Source Options

//#define CONFIG_SYSCLK_SOURCE        SYSCLK_SRC_SLCK_RC

//#define CONFIG_SYSCLK_SOURCE        SYSCLK_SRC_SLCK_XTAL

//#define CONFIG_SYSCLK_SOURCE        SYSCLK_SRC_SLCK_BYPASS

//#define CONFIG_SYSCLK_SOURCE        SYSCLK_SRC_MAINCK_4M_RC

//#define CONFIG_SYSCLK_SOURCE        SYSCLK_SRC_MAINCK_8M_RC

//#define CONFIG_SYSCLK_SOURCE        SYSCLK_SRC_MAINCK_12M_RC

//#define CONFIG_SYSCLK_SOURCE        SYSCLK_SRC_MAINCK_XTAL

//#define CONFIG_SYSCLK_SOURCE        SYSCLK_SRC_MAINCK_BYPASS

#define CONFIG_SYSCLK_SOURCE        SYSCLK_SRC_PLLACK



// ===== System Clock (MCK) Prescaler Options   (Fmck = Fsys / (SYSCLK_PRES))

//#define CONFIG_SYSCLK_PRES          SYSCLK_PRES_1

#define CONFIG_SYSCLK_PRES          SYSCLK_PRES_2

//#define CONFIG_SYSCLK_PRES          SYSCLK_PRES_4

//#define CONFIG_SYSCLK_PRES          SYSCLK_PRES_8

//#define CONFIG_SYSCLK_PRES          SYSCLK_PRES_16

//#define CONFIG_SYSCLK_PRES          SYSCLK_PRES_32

//#define CONFIG_SYSCLK_PRES          SYSCLK_PRES_64

//#define CONFIG_SYSCLK_PRES          SYSCLK_PRES_3



// ===== PLL0 (A) Options   (Fpll = (Fclk * PLL_mul) / PLL_div)

// Use mul and div effective values here.

#define CONFIG_PLL0_SOURCE          PLL_SRC_MAINCK_8M_RC

#define CONFIG_PLL0_MUL             25

#define CONFIG_PLL0_DIV             1



// ===== Target frequency (System clock)

// - Internal RC frequency: 8MHz

// - System clock source: PLLA

// - System clock prescaler: 2 (divided by 2)

// - PLLA source: 8M_RC

// - PLLA output: 8M_RC * 25 / 1

// - System clock: 8M_RC * 25 / 1 / 2 = 100MHz



#endif /* CONF_CLOCK_H_INCLUDED */

#if ((BOARD == SAM4CMP_DB) || (BOARD == SAM4CMS_DB))

#  define EXAMPLE_LED_GPIO    LED4_GPIO

#else

#  define EXAMPLE_LED_GPIO    LED0_GPIO

#endif

void SysTick_Handler(void)

{

        ul_ms_ticks++;

}

int main(void)

{

        sysclk_init();

        board_init();



        /* Setup SysTick Timer for 1 msec interrupts */

        if (SysTick_Config(sysclk_get_cpu_hz() / 1000)) {

                while (1) {  /* Capture error */

                }

        }



        while (1) {

                ioport_toggle_pin_level(EXAMPLE_LED_GPIO);

                mdelay(500);

        }

}