用SAM-BA或JLINK跑ATSAM4E16的程序(16)ASF RTT

#include "asf.h"

#include "stdio_serial.h"

#include "conf_board.h"

#include "conf_clock.h"



/** Device state: in the main menu. */

#define STATE_MAIN_MENU      0

/** Device state: user is setting an alarm time. */

#define STATE_SET_ALARM      1



/** ASCII char definition for backspace. */

#define ASCII_BS    8

/** ASCII char definition for carriage return. */

#define ASCII_CR    13



#define STRING_EOL    "\r"

#define STRING_HEADER "-- RTT Example --\r\n" \

                "-- "BOARD_NAME" --\r\n" \

                "-- Compiled: "__DATE__" "__TIME__" --"STRING_EOL



/** Current device state. */

volatile uint8_t g_uc_state;



/** New alarm time being currently entered. */

volatile uint32_t g_ul_new_alarm;



/** Indicate that an alarm has occurred but has not been cleared. */

volatile uint8_t g_uc_alarmed;



/**

 * \brief Refresh display on terminal.

 *

 * Update the terminal display to show the current menu and the current time

 * depending on the device state.

 */

static void refresh_display(void)

{

        printf("%c[2J\r", 27);

        printf("Time: %u\n\r", (unsigned int)rtt_read_timer_value(RTT));



        /* Display alarm */

        if (g_uc_alarmed) {

                puts("!!! ALARM !!!\r");

        }



        /* Main menu */

        if (g_uc_state == STATE_MAIN_MENU) {

                puts("Menu:\n\r"

                                " r - Reset timer\n\r"

                                " s - Set alarm\r");

                if (g_uc_alarmed) {

                        puts(" c - Clear alarm notification\r");

                }

                puts("\n\rChoice? ");

        } else {

                if (g_uc_state == STATE_SET_ALARM) {

                        puts("Enter alarm time: ");

                        if (g_ul_new_alarm != 0) {

                                printf("%u", (unsigned)g_ul_new_alarm);

                        }

                }

        }

}



/**

 * \brief RTT configuration function.

 *

 * Configure the RTT to generate a one second tick, which triggers the RTTINC

 * interrupt.

 */

static void configure_rtt(void)

{

        uint32_t ul_previous_time;



        /* Configure RTT for a 1 second tick interrupt */

#if SAM4N || SAM4S || SAM4E || SAM4C || SAM4CP || SAM4CM || SAMV71 || SAMV70 || SAME70 || SAMS70

        rtt_sel_source(RTT, false);

#endif

        rtt_init(RTT, 32768);



        ul_previous_time = rtt_read_timer_value(RTT);

        while (ul_previous_time == rtt_read_timer_value(RTT));



        /* Enable RTT interrupt */

        NVIC_DisableIRQ(RTT_IRQn);

        NVIC_ClearPendingIRQ(RTT_IRQn);

        NVIC_SetPriority(RTT_IRQn, 0);

        NVIC_EnableIRQ(RTT_IRQn);

        rtt_enable_interrupt(RTT, RTT_MR_RTTINCIEN);

}



/**

 * \brief Configure the console UART.

 */

static void configure_console(void)

{

        const usart_serial_options_t uart_serial_options = {

                .baudrate = CONF_UART_BAUDRATE,

#ifdef CONF_UART_CHAR_LENGTH

                .charlength = CONF_UART_CHAR_LENGTH,

#endif

                .paritytype = CONF_UART_PARITY,

#ifdef CONF_UART_STOP_BITS

                .stopbits = CONF_UART_STOP_BITS,

#endif

        };



        /* Configure console UART. */

        sysclk_enable_peripheral_clock(CONSOLE_UART_ID);

        stdio_serial_init(CONF_UART, &uart_serial_options);

}



/**

 * \brief Interrupt handler for the RTT.

 *

 * Display the current time on the terminal.

 */

void RTT_Handler(void)

{

        uint32_t ul_status;



        /* Get RTT status */

        ul_status = rtt_get_status(RTT);



        /* Time has changed, refresh display */

        if ((ul_status & RTT_SR_RTTINC) == RTT_SR_RTTINC) {

                refresh_display();

        }



        /* Alarm */

        if ((ul_status & RTT_SR_ALMS) == RTT_SR_ALMS) {

                g_uc_alarmed = 1;

                refresh_display();

        }

}



/**

 * \brief Application entry point for RTT example.

 *

 * Initialize the RTT, display the current time and allow the user to

 * perform several actions: clear the timer, set an alarm, etc.

 *

 * \return Unused (ANSI-C compatibility).

 */

int main(void)

{

        uint8_t c;



        /* Initialize the SAM system */

        sysclk_init();

        board_init();



        /* Configure console UART */

        configure_console();



        /* Output example information */

        puts(STRING_HEADER);



        /* Configure RTT */

        configure_rtt();



        /* Initialize state machine */

        g_uc_state = STATE_MAIN_MENU;

        g_uc_alarmed = 0;

        refresh_display();



        /* User input loop */

        while (1) {

                /* Wait for user input */

                scanf("%c", (char *)&c);



                /* Main menu mode */

                if (g_uc_state == STATE_MAIN_MENU) {

                        /* Reset timer */

                        if (c == 'r') {

                                configure_rtt();

                                refresh_display();

                        } else if (c == 's') { /* Set alarm */

                                g_uc_state = STATE_SET_ALARM;

                                g_ul_new_alarm = 0;

                                refresh_display();

                        } else { /* Clear alarm */

                                if ((c == 'c') && g_uc_alarmed) {

                                        g_uc_alarmed = 0;

                                        refresh_display();

                                }

                        }

                } else if (g_uc_state == STATE_SET_ALARM) { /* Set alarm mode */

                        /* Number */

                        if ((c >= '0') && (c <= '9')) {

                                g_ul_new_alarm = g_ul_new_alarm * 10 + c - '0';

                                refresh_display();

                        } else if (c == ASCII_BS) {

                                printf("%c", c);

                                g_ul_new_alarm /= 10;

                                refresh_display();

                        } else if (c == ASCII_CR) {

                                /* Avoid newAlarm = 0 case */

                                if (g_ul_new_alarm != 0) {

                                        rtt_write_alarm_time(RTT, g_ul_new_alarm);

                                }



                                g_uc_state = STATE_MAIN_MENU;

                                refresh_display();

                        }

                }

        }

}