text: /******************************************************************************
  *
  * Copyright (C) 2014-2016 Xilinx, Inc. All rights reserved.
  *
  * 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:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * Use of the Software is limited solely to applications:
  * (a) running on a Xilinx device, or
  * (b) that interact with a Xilinx device through a bus or interconnect.
  *
  * 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
  * XILINX  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.
  *
  * Except as contained in this notice, the name of the Xilinx shall not be used
  * in advertising or otherwise to promote the sale, use or other dealings in
  * this Software without prior written authorization from Xilinx.
  *
  ******************************************************************************/
  /*****************************************************************************/
  /**
  *
  * @file microblaze_sleep.c
  *
  * Contains implementation of microblaze sleep function.
  *
  * <pre>
  * MODIFICATION HISTORY:
  *
  * Ver   Who  Date	 Changes
  * ----- ---- -------- -------------------------------------------------------
  * 4.1   hk   04/18/14 Add sleep function.
  * 6.0   asa   08/15/16 Updated the sleep/usleep signature. Fix for CR#956899.
  *
  * </pre>
  *
  * @note
  *
  * This file may contain architecture-dependent code.
  *
  ******************************************************************************/
  
  /***************************** Include Files *********************************/
  
  #include "microblaze_sleep.h"
  
  /***************** Macros (Inline Functions) Definitions *********************/
  #define ITERS_PER_SEC	(XPAR_CPU_CORE_CLOCK_FREQ_HZ / 4)
  #define ITERS_PER_MSEC	(ITERS_PER_SEC / 1000)
  #define ITERS_PER_USEC	(ITERS_PER_MSEC / 1000)
  
  #define ITERS_PER_NSEC  (ITERS_PER_USEC / 1000)
  
  
  
  static void sleep_common(u32 n, u32 iters)
  {
  	asm volatile (
  			"1:               \n\t"
  			"addik %1, %1, -1 \n\t"
  			"add   r7, r0, %0 \n\t"
  			"2:               \n\t"
  			"addik r7, r7, -1 \n\t"
  			"bneid  r7, 2b    \n\t"
  			"or  r0, r0, r0   \n\t"
  			"bneid %1, 1b     \n\t"
  			"or  r0, r0, r0   \n\t"
  			:
  			: "r"(iters), "r"(n)
  			: "r0", "r7"
  	);
  }
  
  /*****************************************************************************/
  /**
  * @brief    Provides delay for requested duration.
  
  * @param	useconds- time in nseconds.
  
  * @return	0
  *
  * @note		Instruction cache should be enabled for this to work.
  *
  ******************************************************************************/
  
  int nsleep(unsigned long useconds)
  {
      sleep_common((u32)useconds, ITERS_PER_NSEC);
  
      return 0;
  
  }
  
  /*****************************************************************************/
  /**
  * @brief    Provides delay for requested duration.
  
  * @param	useconds- time in useconds.
  * @return	0
  *
  * @note		Instruction cache should be enabled for this to work.
  *
  ******************************************************************************
  */
  int usleep(unsigned long useconds)
  {
  	sleep_common((u32)useconds, ITERS_PER_USEC);
  
  	return 0;
  }
  /*
  /*****************************************************************************/
  /**
  * @brief    Provides delay for requested duration.
  * @param	seconds- time in seconds.
  
  * @return	0
  *
  * @note		Instruction cache should be enabled for this to work.
  *
  ******************************************************************************/
  unsigned sleep(unsigned int seconds)
  {
  	sleep_common(seconds, ITERS_PER_SEC);
  
  	return 0;
  }
  
  /*****************************************************************************/
  /**
  *
  * @brief    Provides delay for requested duration..
  *
  * @param	MilliSeconds- Delay time in milliseconds.
  *
  * @return	None.
  *
  * @note		Instruction cache should be enabled for this to work.
  *
  ******************************************************************************/
  void MB_Sleep(u32 MilliSeconds)
  {
  	sleep_common(MilliSeconds, ITERS_PER_MSEC);
  }
  