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/*
* File : board.c
* This file is part of RT-Thread RTOS
* COPYRIGHT (C) 2009 RT-Thread Develop Team
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rt-thread.org/license/LICENSE
*
*/
#include <rthw.h>
#include <rtthread.h>
#include <nrf51.h>
#include <nrf51_bitfields.h>
#include "board.h"
#include "uart.h"
/**
* @addtogroup NRF51822
*/
/*@{*/
#define LFCLK_FREQUENCY (32768UL) /**< LFCLK frequency in Hertz, constant. */
#define RTC_FREQUENCY (800UL) /**< Required RTC working clock RTC_FREQUENCY Hertz. Changable. */
#define COUNTER_PRESCALER ((LFCLK_FREQUENCY / RTC_FREQUENCY) - 1) /* f = LFCLK/(prescaler + 1) */
/** @brief Function starting the internal LFCLK XTAL oscillator.
*/
void lfclk_config(void)
{
NRF_CLOCK->LFCLKSRC = (CLOCK_LFCLKSRC_SRC_Xtal << CLOCK_LFCLKSRC_SRC_Pos);
NRF_CLOCK->EVENTS_LFCLKSTARTED = 0;
NRF_CLOCK->TASKS_LFCLKSTART = 1;
while (NRF_CLOCK->EVENTS_LFCLKSTARTED == 0)
{
//Do nothing.
}
NRF_CLOCK->EVENTS_LFCLKSTARTED = 0;
}
/** @brief Function for configuring the RTC with TICK to 100Hz.
*/
void rtc_config(void)
{
NVIC_EnableIRQ(RTC0_IRQn); // Enable Interrupt for the RTC in the core.
NRF_RTC0->PRESCALER = COUNTER_PRESCALER; // Set prescaler to a TICK of RTC_FREQUENCY.
// Enable TICK event and TICK interrupt:
NRF_RTC0->EVTENSET = RTC_EVTENSET_TICK_Msk;
NRF_RTC0->INTENSET = RTC_INTENSET_TICK_Msk;
}
/** @brief: Function for handling the RTC0 interrupts.
* Triggered on TICK and COMPARE0 match.
*/
void RTC0_IRQHandler(void)
{
/* enter interrupt */
rt_interrupt_enter();
if ((NRF_RTC0->EVENTS_TICK != 0) &&
((NRF_RTC0->INTENSET & RTC_INTENSET_TICK_Msk) != 0))
{
NRF_RTC0->EVENTS_TICK = 0;
rt_tick_increase(); //This function will notify kernel there is one tick passed
}
/* leave interrupt */
rt_interrupt_leave();
}
/**
* This function will initial NRF51822 board.
*/
void rt_hw_board_init()
{
lfclk_config();
rtc_config();
NRF_RTC0->TASKS_START = 1;
/* Initial usart deriver, and set console device */
rt_hw_uart_init();
#ifdef RT_USING_CONSOLE
rt_console_set_device(RT_CONSOLE_DEVICE_NAME);
#endif
}
/*@}*/
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