自学教程：C++ CPU_PRESCALE函数代码示例

void CPsydukCore::Initialise() {		CPU_PRESCALE(CPU_125kHz);	_delay_ms(1);           // allow slow power supply startup	CPU_PRESCALE(CPU_16MHz); // set for 16 MHz clock		usb_init();	while (!usb_configured()) {	}		Delay(2000);		m_bIsInitialised = true;}

/** Configures the board hardware and chip peripherals for the demo's functionality. */void SetupHardware(void){    /* Disable watchdog */    //MCUSR &= ~(1 << WDRF);    //wdt_disable();		//Switch off JTAG (to free up ports F pins 4,5,6,7)	MCUCR = (1 << JTD) | (1 << IVCE) | (0 << PUD);	MCUCR = (1 << JTD) | (0 << IVSEL) | (0 << IVCE) | (0 << PUD); 	//#define DISABLE_JTAG_APPLICATION	// Clock @ 16Mhz	CPU_PRESCALE(0);		//adc_init();		//Initialise AVR Pins    DDRA=0x00;    DDRB=0x00;    DDRC=0x00;    DDRD=0x00;    DDRE=0x00;    DDRF=0x00;    PORTA=0xFF;    PORTB=0xFF;    PORTC=0xFF;    PORTD=0xFF;    PORTE=0xFF;    PORTF=0xFF;    /* Hardware Initialization */    USB_Init();}

int main(void){	uint16_t val, count=1;	// set for 16 MHz clock, and turn on the LED	CPU_PRESCALE(0);	LED_CONFIG;	LED_ON;	// initialize the USB, and then wait for the host	// to set configuration.  If the Teensy is powered	// without a PC connected to the USB port, this 	// will wait forever.	usb_init();	while (!usb_configured()) /* wait */ ;	// wait an extra second for the PC's operating system	// to load drivers and do whatever it does to actually	// be ready for input	_delay_ms(1000);	// start printing stuff.  If hid_listen is running on	// the host, this should appear.	print("USB debug only example/n");	while (1) {		print("Hello World ");		phex16(count++);		print("/n");		_delay_ms(1000);	}}

int main(void){    // set for 16 MHz clock    CPU_PRESCALE(0);    LED_CONFIG;    LED_OFF;    // Initialize the USB, and then wait for the host to set configuration.    // If the Teensy is powered without a PC connected to the USB port,    // this will wait forever.    usb_init();    while (!usb_configured()) /* wait */ ;    // Wait an extra second for the PC's operating system to load drivers    // and do whatever it does to actually be ready for input    _delay_ms(1000);    // Setup the timer interrupt that handles the touch screen,    // and setup the ADC    setup();    // initialize PIN D0 as digital input, others are set to     // pullup resistor    DDRD = 0b00000000;     DDRD = 0b11111110;     // Enable interrupts    sei();    while (1) {}}

/* returns * - success: 0 */uint8_t teensy_init(void) {	// CPU speed : should match F_CPU in makefile	#if F_CPU != 16000000		#error "Expecting different CPU frequency"	#endif	CPU_PRESCALE(CPU_16MHz);	// PD2 as interrupt for N35P112	DDRD &=~ (1 << 2); //Input	PORTD |= (1 << 2); //Use Pullup	// PD3 as reset for N35P112	DDRD |= (1 << 3); //Output	// PB7 as pushbutton for N35P112	DDRB &=~ (1 << 7); //Input	PORTB &=~ (1 << 7); //No Pullup	// I2C (TWI)	uint8_t twiPrescaler = TWI_BIT_PRESCALE_1;	uint8_t twiBitRate = TWI_BITLENGTH_FROM_FREQ(1, TWI_FREQ);	TWI_Init(twiPrescaler, twiBitRate);	return 0;  // success}

/** Main program entry point. This routine contains the overall program flow, including initial *  setup of all components and the main program loop. */int main(void){  unsigned char i;	// set for 16 MHz clock, and make sure the LED is off	CPU_PRESCALE(0);	LED_CONFIG;	LED_OFF;		// Justy's bootup LED hack  int d,e;	for (d=0; d<100; d++) {    LED_ON;		_delay_ms(1+.1*d);  LED_OFF;  _delay_ms(21-.1*d);	}			SetupHardware();	LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);	sei();	for (;;)	{		MS_Device_USBTask(&Disk_MS_Interface);		USB_USBTask();	}}

int main(void){	int8_t x, y, *p;	uint8_t i;	// set for 16 MHz clock	CPU_PRESCALE(0);	LED_CONFIG;	LED_OFF;	// Initialize the USB, and then wait for the host to set configuration.	// If the Teensy is powered without a PC connected to the USB port,	// this will wait forever.	usb_init();	while (!usb_configured()) /* wait */ ;	// Wait an extra second for the PC's operating system to load drivers	// and do whatever it does to actually be ready for input	_delay_ms(1000);	while (1) {		// This sequence creates a left click		usb_mouse_buttons(1, 0, 0);		_delay_ms(10);		usb_mouse_buttons(0, 0, 0);	}}

int main (void){    uint8_t i;    CPU_PRESCALE(0);    DDRB = 0xff;    DDRD = 0xff;    usb_init();    while(!usb_configured());    usb_buffer[0] = 0xab;    usb_buffer[1] = 0xcd;     usb_buffer[63] = 4;    led();/*    controller_mode = probe;*/    controller_mode = poll;    while(1){        switch(controller_mode){            case(probe):                _delay_ms(12);                controller_probe();                usb_rawhid_send(usb_buffer, 50);                break;            case(poll):                controller_poll();                usb_rawhid_send(usb_buffer, 50);               _delay_ms(6);                break;        }    }    return 0;}

int main(void){	CPU_PRESCALE(CPU_16MHz);	SPI_SlaveInit();	InitWEnc();		u08 main_msg;		// Start keeping track of position at 0	WE_wheel_0 = 0;	while(!WE_wheel_0);	WE_position = 0;		// Loop indefinitely	while(1)	{		// obtain command from main uC		main_msg = SPI_SlaveReceive();		switch(main_msg)		{			case SPI_WHEEL_POS:			SPI_SlaveReceiveX(WE_position);			break;						case SPI_WHEEL_RPM:			SPI_SlaveReceiveX(WE_RPM);			break;						default:			break;		}	}}

int main(void){    unsigned char i;    // set for 16 MHz clock, and make sure the LED is off    CPU_PRESCALE(0);    LED_CONFIG;    LED_OFF;    // initialize the USB, but don't want for the host to    // configure.  The first several messages sent will be    // lost because the PC hasn't configured the USB yet,    // but we care more about blinking than debug messages!    usb_init();    // blink morse code messages!    while (1) {        for (i=0; i<6; i++) {            morse_P(PSTR("SOS"));            _delay_ms(1500);        }        morse_P(PSTR("DOES ANYBODY STILL KNOW MORSE CODE?"));        _delay_ms(4000);    }}

int main(void){    // set for 16 MHz clock    CPU_PRESCALE(0);    // Initialize the USB, and then wait for the host to set configuration.    // If the Teensy is powered without a PC connected to the USB port,    // this will wait forever.    usb_init();    while (!usb_configured()) /* wait */ ;    keyboard_init();    host_set_driver(pjrc_driver());#ifdef SLEEP_LED_ENABLE    sleep_led_init();#endif    while (1) {        while (suspend) {            suspend_power_down();            if (remote_wakeup && suspend_wakeup_condition()) {                usb_remote_wakeup();            }        }        keyboard_task();     }}

void setup() {  CPU_PRESCALE(0x03);  CONFIG_OUT_B(0);  CONFIG_OUT_B(1);  CONFIG_OUT_B(2);  CONFIG_OUT_B(3);  CONFIG_OUT_B(4);  CONFIG_OUT_B(5);  CONFIG_OUT_B(6);  CONFIG_OUT_B(7);  CONFIG_OUT_C(6);  CONFIG_OUT_C(7);  CONFIG_OUT_D(0);  CONFIG_OUT_D(1);  CONFIG_OUT_D(2);  CONFIG_IN_D(3); // switch  LED_ON_D(3); // pullup resistor  CONFIG_OUT_D(4);  CONFIG_IN_D(5); // switch  LED_ON_D(5); // pullup resistor  CONFIG_OUT_D(6);  CONFIG_OUT_D(7);  CONFIG_OUT_F(7);}

void init(){	GTCCR |= (1 << PSRSYNC);	CPU_PRESCALE(0);	USART_init(BAUD_RATE);	USART_send_string("/n/nWe're online jack!/r/n");	new_motor_state = 0;	DDRD = 0xFF;	PORTD = 0x50;	sei();	UCSR1B |= (1 << RXCIE1);	if (UCSR1B & ~(1 << RXCIE1)){		USART_send_string("Recieving Interrupt enabled./r/n");	}	TCCR0B &= 0b11110000;	TCCR0B |= 0b00000101;	//Max prescaling	TCCR0A &= 0b11111100;	//Normal mode...	OCR0A = 255;	TIMSK0 |= 0b00000010;	USART_send_string("Set timer to use CPU ticks, normal mode, with 255 comparison.");}

intmain(void){  static uint8_t state[16];  static uint8_t prev_state[16];  // set for 16 MHz clock  CPU_PRESCALE(0);  init_keyboard_interface();  // Initialize the USB, and then wait for the host to set configuration.  // If the Teensy is powered without a PC connected to the USB port,  // this will wait forever.  usb_init();  while (!usb_configured()) /* wait */ ;  // Wait for the PC's operating system to load drivers  // and do whatever it does to actually be ready for input  _delay_ms(3000);  memset(prev_state, 0, sizeof prev_state);  while (1) {    poll_keyboard(state);    if (memcmp(state, prev_state, sizeof state)) {      send_keys(state);      memcpy(prev_state, state, sizeof state);    }    _delay_ms(10);  }}

int main(void) {    CPU_PRESCALE(0);    GBA_DDR &= ~(1<<MISO_BIT);    GBA_DDR |= (1<<MOSI_BIT) | (1<<CLK_BIT);    CLK_HIGH();    usb_init();    while (!usb_configured());    _delay_ms(1000);    INIT_TIMER();    while (1) {        if (usb_serial_available() >= 4) {            uint32_t data = 0;            data |= (uint32_t)usb_serial_getchar()<<24;            data |= (uint32_t)usb_serial_getchar()<<16;            data |= (uint32_t)usb_serial_getchar()<<8;            data |= (uint32_t)usb_serial_getchar();            xfer(&data);            usb_serial_putchar((data>>24) & 0xff);            usb_serial_putchar((data>>16) & 0xff);            usb_serial_putchar((data>>8) & 0xff);            usb_serial_putchar(data & 0xff);            usb_serial_flush_output();        }    }

/** Configures all hardware required for the bootloader. */void SetupHardware(void){	/* Disable watchdog if enabled by bootloader/fuses */	MCUSR &= ~(1 << WDRF);	wdt_disable();	/* Disable clock division */	clock_prescale_set(clock_div_1);	/* Relocate the interrupt vector table to the bootloader section */	MCUCR = (1 << IVCE);	MCUCR = (1 << IVSEL);		LED_SETUP();	CPU_PRESCALE(0); 	L_LED_OFF();	TX_LED_OFF();	RX_LED_OFF();		/* Initialize TIMER1 to handle bootloader timeout and LED tasks.  	 * With 16 MHz clock and 1/64 prescaler, timer 1 is clocked at 250 kHz	 * Our chosen compare match generates an interrupt every 1 ms.	 * This interrupt is disabled selectively when doing memory reading, erasing,	 * or writing since SPM has tight timing requirements.	 */ 	OCR1AH = 0;	OCR1AL = 250;	TIMSK1 = (1 << OCIE1A);					// enable timer 1 output compare A match interrupt	TCCR1B = ((1 << CS11) | (1 << CS10));	// 1/64 prescaler on timer 1 input	/* Initialize USB Subsystem */	USB_Init();}

/* returns * - success: 0 */uint8_t teensy_init(void) {	CPU_PRESCALE(CPU_16MHz);  // speed should match F_CPU in makefile	// onboard LED	DDRD  &= ~(1<<6);  // set D(6) as input	PORTD &= ~(1<<6);  // set D(6) internal pull-up disabled	// keyboard LEDs (see "PWM on ports OC1(A|B|C)" in "teensy-2-0.md")	_led_all_off();  // (just to put the pins in a known state)	TCCR1A  = 0b10101001;  // set and configure fast PWM	TCCR1B  = 0b00001001;  // set and configure fast PWM	// I2C (TWI)	twi_init();  // on pins D(1,0)	// unused pins	teensypin_write_all_unused(DDR, CLEAR); // set as input	teensypin_write_all_unused(PORT, SET);  // set internal pull-up enabled	// rows	teensypin_write_all_row(DDR, CLEAR); // set as input	teensypin_write_all_row(PORT, SET);  // set internal pull-up enabled	// columns	teensypin_write_all_column(DDR, CLEAR);   // set as input (hi-Z)	teensypin_write_all_column(PORT, CLEAR);  // set internal pull-up	                                          //   disabled	return 0;  // success}

int main(void) {	CPU_PRESCALE(CPU_16MHz);	usb_init();	while (!usb_configured()) /* wait */		_delay_ms(1000);	init_cols();	//  TCCR0A = 0x00;	//	TCCR0B =(1<<CS00);	//	TIMSK0 = (1<<TOIE0);	////////////////////////////////////////////////			DDRD |= (1 << 5);			PORTD &= ~(1 << 5);			for(r=0;r<10;r++){			keyboard_keys[0] = KEY_CAPS_LOCK;			usb_keyboard_send();			_delay_ms(100);			keyboard_keys[0] = 0;			usb_keyboard_send();			_delay_ms(500);			}			if (PIND & (1 << 6)){					unselect_rows();					_delay_ms(500);					pokerMode();			}else{				unselect_rows();				_delay_ms(500);				osuMode();			}}

/* ******************************************************************************** * main ******************************************************************************** */int main( void ){    /* Disable watchdog if enabled by bootloader/fuses */    MCUSR &= ~(1 << WDRF);    wdt_disable();    /* Disable clock division */    CPU_PRESCALE(0);    LED_CONFIG;    LED_ON;        /* Initialize Keyboard Driver */    KB_Init();    /* Initialize Mouse Driver */    MS_Init();        /* Initialize USB Joystick variables */    usb_joystick_raz();    /* Enable interrupts */    sei( );    /* Initialize USB Joystick */    usb_init();    while (!usb_configured()) ;    _delay_ms(1000);    LED_OFF;    /* Send a first packet */    usb_joystick_send();    /* Reset the mouse */    MS_MouseReset();    /*	 * Comment that code to test rotation speed for a given position.	 */    while( 1 )    {        KB_EventTask();		MS_EventTask();    }        /*     * Uncomment that code to test rotation speed for a given position.     *///	while( 1 )//    {//		usb_joystick_move_zrz(153, 128);//		usb_joystick_send();//		_delay_ms(5000);//	}    return 0;}

void init(void){		CPU_PRESCALE(CPU_16MHz);	adc_init();	Counter_init();	port_init();	uart_init();	sei();}

//MAIN//*****************************//*****************************int main(){    CPU_PRESCALE(CPU_8MHz);    port_init();    adc_init(); //son of a bitch    uart_init();    mp3_func(CMD_SET_VOLUME, MAX_VOL);    //deactivate relay (it's active low)    PORTD |= 0x00;     static uint8_t timeout;    /* init hardware pins */ //   nrf24_init();        /* Channel #21 , payload length: 4 */ //   nrf24_config(21,4);     /* Set the device addresses */ //   nrf24_tx_address(tx_address); //   nrf24_rx_address(rx_address);   while(1)   {            //if(playmode==PLAY){q++; if(q>50){playmode = OFF;q=0;}}    //  while(!nrf24_dataReady()){if(timeout>1000){break;} timeout++;} //wait for transmission    //  if(nrf24_dataReady())      {    //        nrf24_getData(data_array); 		    if(data_array[0] == 0xFF) //warning system control	    {	     light_func(data_array[1]);	      mp3_func(CMD_PLAY_W_INDEX, data_array[2]);          //    light_test_routine();            }  	    if(data_array[3]) //snow check is set	    { 	     ADCSRA |= 1<<ADSC; //request value	     while (bit_is_clear(ADCSRA, ADIF)){} //shouldn't take long	     reading = ADCH;  	     data_array[3] = reading;	    }        }                 	//*****************************        // Radio Operation - send snow data back	 /* Automatically goes to TX mode */	//	  nrf24_send(data_array);        			  	 /* Wait for transmission to end */ 	//	  while(nrf24_isSending());       // nrf24_powerUpRx();	_delay_ms(500); //wait a little while longer before repeat    }//while}//main

// Very simple character echo testint main(void){	CPU_PRESCALE(0);	usb_init();	while (1) {		int n = usb_serial_getchar();		if (n >= 0) usb_serial_putchar(n);	}}

void initialize(bool verbose){	CPU_PRESCALE(0);	USART_init(BAUD_RATE);	USART_transmit('/f');	// Send form feed to clear the terminal.	if (verbose)		USART_send_string("WunderBoard initializing.../r/n");	if (verbose)		USART_send_string("/tSetting ADC prescaler and disabling free running "				"mode.../r/n");	setup_ADC(ADC_PRESCALER_32, FALSE);	if (verbose)		USART_send_string("/tEnabling ADC.../r/n");	ADC_enable();	if (verbose)		USART_send_string("/tSetting ADC reference to Vcc.../r/n");	ADC_set_reference(ADC_REF_VCC);	// Configure IO //	if (verbose)		USART_send_string("/tConfiguring IO.../r/n");	//DDRx corresponds to PORTx/PINx, dependng on direction of data flow --	//PORT for output, PIN for input	DDRA = 0x00;	// Buttons and switches	DDRB = 0b11100111;	// Red enable, green enable and audio out	DDRC = 0b11111111;	// Discrete LEDs	DDRE = 0b01000111;	// LED Column	DDRF = 0x00;	// Accelerometer	// Disable pullups and set outputs low //	PORTA = 0x00;	PORTB = 0b00000001;	PORTC = 0x00;	PORTE = 0x00;	PORTF = 0x00;	if (verbose)		USART_send_string("/tSetting SPI/r/n");	//Set the SPI bus appropriately to use the LED array	SPCR = (1<<SPE)|(1<<MSTR)|(1<<SPR0);}

void setupCpuFrequency(void){    is_8Mhz = extdata_getValue8(EXTDATA_CPU_CORE_CLOCK) == EXTDATA_CPU_CORE_CLOCK_F_8MHZ;    if(!is_8Mhz)    {        // set CPU speed to 16Mhz        CPU_PRESCALE(0);    }}

void configure_teensy(){    // set for 16 MHz clock, and make sure the LED is off    CPU_PRESCALE(0);    // normal mode, 2 MHz, count to 2^16 and roll over    TCCR1A = 0x00;    TCCR1B = 0x02;    TCCR1C = 0x00;}

int main(void){  CPU_PRESCALE(CPU_8MHz);  DDRD |= (1<<6); //set bit 6 of dynamic data register D to output.  while(1){    PORTD |= (1<<6);  }  return 0;}

int main(void) {	// Set clock @ 8Mhz	CPU_PRESCALE(1);	sei();	twi_slave_init();	twi_slave_enable();	for (;;);}

int main(void){    // set for 16 MHz clock    CPU_PRESCALE(0);    // Initialize the USB, and then wait for the host to set configuration.    // If the Teensy is powered without a PC connected to the USB port,    // this will wait forever.    usb_init();    while (!usb_configured()) /* wait */ ;    print_set_sendchar(sendchar);    keyboard_init();    host_set_driver(pjrc_driver());#ifdef SLEEP_LED_ENABLE    sleep_led_init();#endif    while (1) {		uint32_t mtl_time = timer_read32();		for ( int i = 0; i < 1000; i++ ) {			/*print( "Main loop: i = " );*/			/*phex( (uint8_t) ( i >> 8 ) & 0xff );*/			/*phex( (uint8_t) ( i >> 0 ) & 0xff );*/			/*print( "/n" );*/        while (suspend) {            suspend_power_down();            if (remote_wakeup && suspend_wakeup_condition()) {                usb_remote_wakeup();            }        }        keyboard_task(); 		}		mtl_time = timer_elapsed32( mtl_time );		// No TP: 247 ms		// TP full: 10820 ms		// No usb report: same as TP full//		print( "Time for 1,000 keyboard_tasks: " );//		phex( (uint8_t) ( mtl_time >> 24 ) & 0xff );//		phex( (uint8_t) ( mtl_time >> 16 ) & 0xff );//		phex( (uint8_t) ( mtl_time >>  8 ) & 0xff );//		phex( (uint8_t) ( mtl_time >>  0 ) & 0xff );//		print( "/n" );	}}

int main(void){  CPU_PRESCALE( CPU_16MHz );  LED_CONFIG;  while (1) {    LED_ON;    _delay_ms(1000);    LED_OFF;    _delay_ms(1000);  }}

int main(void) {    CPU_PRESCALE(0);    LED_CONFIG;    LED_OFF;    while(1){        LED_ON;        _delay_ms(500);        LED_OFF;        _delay_ms(500);    }}