text: /* Teensyduino Core Library
   * http://www.pjrc.com/teensy/
   * Copyright (c) 2019 PJRC.COM, LLC.
   *
   * Permission is hereby granted, free of charge, to any person obtaining
   * a copy of this software and associated documentation files (the
   * "Software"), to deal in the Software without restriction, including
   * without limitation the rights to use, copy, modify, merge, publish,
   * distribute, sublicense, and/or sell copies of the Software, and to
   * permit persons to whom the Software is furnished to do so, subject to
   * the following conditions:
   *
   * 1. The above copyright notice and this permission notice shall be 
   * included in all copies or substantial portions of the Software.
   *
   * 2. If the Software is incorporated into a build system that allows 
   * selection among a list of target devices, then similar target
   * devices manufactured by PJRC.COM must be included in the list of
   * target devices and selectable in the same manner.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
   * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
   * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
   * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   */
  
  #include "imxrt.h"
  #include "debug/printf.h"
  
  
  unsigned long rtc_get(void)
  {
  	uint32_t hi1 = SNVS_HPRTCMR;
  	uint32_t lo1 = SNVS_HPRTCLR;
  	while (1) {
  		uint32_t hi2 = SNVS_HPRTCMR;
  		uint32_t lo2 = SNVS_HPRTCLR;
  		if (lo1 == lo2 && hi1 == hi2) {
  			return (hi2 << 17) | (lo2 >> 15);
  		}
  		hi1 = hi2;
  		lo1 = lo2;
  	}
  }
  
  void rtc_set(unsigned long t)
  {
  	// stop the RTC
  	SNVS_HPCR &= ~(SNVS_HPCR_RTC_EN | SNVS_HPCR_HP_TS);
  	while (SNVS_HPCR & SNVS_HPCR_RTC_EN); // wait
  	// stop the SRTC
  	SNVS_LPCR &= ~SNVS_LPCR_SRTC_ENV;
  	while (SNVS_LPCR & SNVS_LPCR_SRTC_ENV); // wait
  	// set the SRTC
  	SNVS_LPSRTCLR = t << 15;
  	SNVS_LPSRTCMR = t >> 17;
  	// start the SRTC
  	SNVS_LPCR |= SNVS_LPCR_SRTC_ENV;
  	while (!(SNVS_LPCR & SNVS_LPCR_SRTC_ENV)); // wait
  	// start the RTC and sync it to the SRTC
  	SNVS_HPCR |= SNVS_HPCR_RTC_EN | SNVS_HPCR_HP_TS;
  }
  
  void rtc_compensate(int adjust)
  {
  }
  
  