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[/] [neorv32/] [trunk/] [sw/] [lib/] [source/] [neorv32_mtime.c] - Blame information for rev 64

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// #################################################################################################
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// # << NEORV32: neorv32_mtime.c - Machine System Timer (MTIME) HW Driver >>                       #
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// # ********************************************************************************************* #
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// # BSD 3-Clause License                                                                          #
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// #                                                                                               #
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// # Copyright (c) 2021, Stephan Nolting. All rights reserved.                                     #
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// #                                                                                               #
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// # Redistribution and use in source and binary forms, with or without modification, are          #
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// # permitted provided that the following conditions are met:                                     #
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// #                                                                                               #
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// # 1. Redistributions of source code must retain the above copyright notice, this list of        #
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// #    conditions and the following disclaimer.                                                   #
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// #                                                                                               #
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// # 2. Redistributions in binary form must reproduce the above copyright notice, this list of     #
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// #    conditions and the following disclaimer in the documentation and/or other materials        #
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// #    provided with the distribution.                                                            #
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// #                                                                                               #
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// # 3. Neither the name of the copyright holder nor the names of its contributors may be used to  #
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// #    endorse or promote products derived from this software without specific prior written      #
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// #    permission.                                                                                #
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// #                                                                                               #
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// # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS   #
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// # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF               #
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// # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE    #
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// # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,     #
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// # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE #
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// # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED    #
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// # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING     #
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// # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED  #
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// # OF THE POSSIBILITY OF SUCH DAMAGE.                                                            #
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// # ********************************************************************************************* #
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// # The NEORV32 Processor - https://github.com/stnolting/neorv32              (c) Stephan Nolting #
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// #################################################################################################
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/**********************************************************************//**
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 * @file neorv32_mtime.c
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 * @author Stephan Nolting
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 * @brief Machine System Timer (MTIME) HW driver source file.
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 *
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 * @note These functions should only be used if the MTIME unit was synthesized (IO_MTIME_EN = true).
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 **************************************************************************/
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#include "neorv32.h"
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#include "neorv32_mtime.h"
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/**********************************************************************//**
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 * Check if MTIME unit was synthesized.
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 *
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 * @return 0 if MTIME was not synthesized, 1 if MTIME is available.
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 **************************************************************************/
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int neorv32_mtime_available(void) {
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  if (NEORV32_SYSINFO.SOC & (1 << SYSINFO_SOC_IO_MTIME)) {
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    return 1;
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  }
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  else {
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    return 0;
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  }
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}
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/**********************************************************************//**
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 * Set current system time.
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 *
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 * @note The MTIME timer increments with the primary processor clock.
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 *
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 * @param[in] time New system time (uint64_t)
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 **************************************************************************/
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void neorv32_mtime_set_time(uint64_t time) {
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  union {
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    uint64_t uint64;
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    uint32_t uint32[sizeof(uint64_t)/2];
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  } cycles;
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  cycles.uint64 = time;
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  NEORV32_MTIME.TIME_LO = 0;
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  NEORV32_MTIME.TIME_HI = cycles.uint32[1];
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  NEORV32_MTIME.TIME_LO = cycles.uint32[0];
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}
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/**********************************************************************//**
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 * Get current system time.
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 *
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 * @note The MTIME timer increments with the primary processor clock.
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 *
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 * @return Current system time (uint64_t)
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 **************************************************************************/
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uint64_t neorv32_mtime_get_time(void) {
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  union {
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    uint64_t uint64;
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    uint32_t uint32[sizeof(uint64_t)/2];
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  } cycles;
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  uint32_t tmp1, tmp2, tmp3;
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  while(1) {
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    tmp1 = NEORV32_MTIME.TIME_HI;
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    tmp2 = NEORV32_MTIME.TIME_LO;
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    tmp3 = NEORV32_MTIME.TIME_HI;
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    if (tmp1 == tmp3) {
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      break;
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    }
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  }
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  cycles.uint32[0] = tmp2;
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  cycles.uint32[1] = tmp3;
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  return cycles.uint64;
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}
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/**********************************************************************//**
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 * Set compare time register (MTIMECMP) for generating interrupts.
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 *
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 * @note The interrupt is triggered when MTIME >= MTIMECMP.
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 * @note Global interrupts and the timer interrupt source have to be enabled .
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 *
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 * @param[in] timecmp System time for interrupt (uint64_t)
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 **************************************************************************/
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void neorv32_mtime_set_timecmp(uint64_t timecmp) {
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  union {
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    uint64_t uint64;
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    uint32_t uint32[sizeof(uint64_t)/2];
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  } cycles;
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  cycles.uint64 = timecmp;
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  NEORV32_MTIME.TIMECMP_LO = -1; // prevent MTIMECMP from temporarily becoming smaller than the lesser of the old and new values
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  NEORV32_MTIME.TIMECMP_HI = cycles.uint32[1];
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  NEORV32_MTIME.TIMECMP_LO = cycles.uint32[0];
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}
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/**********************************************************************//**
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 * Get compare time register (MTIMECMP).
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 *
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 * @return Current MTIMECMP value.
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 **************************************************************************/
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uint64_t neorv32_mtime_get_timecmp(void) {
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  union {
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    uint64_t uint64;
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    uint32_t uint32[sizeof(uint64_t)/2];
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  } cycles;
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  cycles.uint32[0] = NEORV32_MTIME.TIMECMP_LO;
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  cycles.uint32[1] = NEORV32_MTIME.TIMECMP_HI;
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  return cycles.uint64;
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}

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