CLK_Gen_functions.c

#include <stdbool.h>
#include <stdint.h>
#include "nrf.h"
#include "nrf_gpiote.h"
#include "nrf_gpio.h"
#include "nrf_delay.h"

#include "Universal.h"

//if SDK210 v2.0 is enabled  PPI chanels available 0-7
//													 PPI groups  available 0-1
//nedd to use Timer1 || Timer2. TIMER0 reserved for SoftDevice

void init_GPIOTE(void) {
    nrf_gpio_cfg_output(PIN_CLK);
    nrf_gpiote_task_config(CHANNEL_GPIOTE, PIN_CLK, NRF_GPIOTE_POLARITY_TOGGLE, NRF_GPIOTE_INITIAL_VALUE_LOW);
}

void init_PPI(void) {
	NRF_PPI->CH[CHANNEL_PPI].EEP = (uint32_t)&NRF_TIMER2->EVENTS_COMPARE[0];					//at what event
	NRF_PPI->CH[CHANNEL_PPI].TEP = (uint32_t)&NRF_GPIOTE->TASKS_OUT[CHANNEL_GPIOTE];	//what task to activate

	NRF_PPI->CHEN = (PPI_CHEN_CH1_Enabled << PPI_CHEN_CH1_Pos);
}

void init_Timer2(void) {
	NRF_CLOCK->TASKS_HFCLKSTART     = 1;
	NRF_CLOCK->EVENTS_HFCLKSTARTED  = 0;
	
	while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0)  {
		;
	}

	NRF_TIMER2->TASKS_CLEAR = 1;
	
	// 2 4   MHz
	// 3 3   MHz real 2.7
	// 4 2.2 MHz
	// 5 1.6 MHz
	// 6 1.47MHz
	// 7 1.2 MHz
	// 8 1   MHz
	// 9 0.9 MHz
	
	NRF_TIMER2->CC[0]     = 3; //4 ||5 to get 3.5MHz
	NRF_TIMER2->PRESCALER = 0;
	
	NRF_TIMER2->BITMODE   = TIMER_BITMODE_BITMODE_08Bit;
	NRF_TIMER2->MODE      = TIMER_MODE_MODE_Timer;
	NRF_TIMER2->SHORTS    = (TIMER_SHORTS_COMPARE0_CLEAR_Enabled << TIMER_SHORTS_COMPARE0_CLEAR_Pos);
}

void Start_CLK() {
	NRF_TIMER2->TASKS_START = 1;    // Start event generation.
}

void Stop_CLK() {
	NRF_TIMER2->TASKS_STOP = 1;    // Stop event generation.
	nrf_delay_ms(10);
	nrf_gpio_pin_clear(PIN_CLK);
	nrf_gpiote_task_config(CHANNEL_GPIOTE, PIN_CLK, NRF_GPIOTE_POLARITY_TOGGLE, NRF_GPIOTE_INITIAL_VALUE_LOW);
}


void init_CLK() {
	init_GPIOTE();
	init_Timer2();
	init_PPI();
	Stop_CLK();
}