OpenCores
URL https://opencores.org/ocsvn/neorv32/neorv32/trunk

Subversion Repositories neorv32

[/] [neorv32/] [trunk/] [sw/] [lib/] [source/] [neorv32_mtime.c] - Blame information for rev 12

Go to most recent revision | Details | Compare with Previous | View Log

Line No. Rev Author Line
1 2 zero_gravi
// #################################################################################################
2
// # << NEORV32: neorv32_mtime.c - Machine System Timer (MTIME) HW Driver >>                       #
3
// # ********************************************************************************************* #
4
// # BSD 3-Clause License                                                                          #
5
// #                                                                                               #
6
// # Copyright (c) 2020, Stephan Nolting. All rights reserved.                                     #
7
// #                                                                                               #
8
// # Redistribution and use in source and binary forms, with or without modification, are          #
9
// # permitted provided that the following conditions are met:                                     #
10
// #                                                                                               #
11
// # 1. Redistributions of source code must retain the above copyright notice, this list of        #
12
// #    conditions and the following disclaimer.                                                   #
13
// #                                                                                               #
14
// # 2. Redistributions in binary form must reproduce the above copyright notice, this list of     #
15
// #    conditions and the following disclaimer in the documentation and/or other materials        #
16
// #    provided with the distribution.                                                            #
17
// #                                                                                               #
18
// # 3. Neither the name of the copyright holder nor the names of its contributors may be used to  #
19
// #    endorse or promote products derived from this software without specific prior written      #
20
// #    permission.                                                                                #
21
// #                                                                                               #
22
// # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS   #
23
// # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF               #
24
// # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE    #
25
// # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,     #
26
// # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE #
27
// # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED    #
28
// # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING     #
29
// # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED  #
30
// # OF THE POSSIBILITY OF SUCH DAMAGE.                                                            #
31
// # ********************************************************************************************* #
32
// # The NEORV32 Processor - https://github.com/stnolting/neorv32              (c) Stephan Nolting #
33
// #################################################################################################
34
 
35
 
36
/**********************************************************************//**
37
 * @file neorv32_mtime.c
38
 * @author Stephan Nolting
39
 * @brief Machine System Timer (MTIME) HW driver source file.
40
 *
41
 * @note These functions should only be used if the MTIME unit was synthesized (IO_MTIME_USE = true).
42
 **************************************************************************/
43
 
44
#include "neorv32.h"
45
#include "neorv32_wdt.h"
46
 
47
 
48
/**********************************************************************//**
49
 * Check if MTIME unit was synthesized.
50
 *
51
 * @return 0 if MTIME was not synthesized, 1 if MTIME is available.
52
 **************************************************************************/
53
int neorv32_mtime_available(void) {
54
 
55 12 zero_gravi
  if (SYSINFO_FEATURES & (1 << SYSINFO_FEATURES_IO_MTIME)) {
56 2 zero_gravi
    return 1;
57
  }
58
  else {
59
    return 0;
60
  }
61
}
62
 
63
 
64
/**********************************************************************//**
65 11 zero_gravi
 * Set current system time.
66 2 zero_gravi
 *
67
 * @note The MTIME timer increments with the primary processor clock.
68
 *
69 11 zero_gravi
 * @param[in] time New system time (uint64_t)
70
 **************************************************************************/
71
void neorv32_mtime_set_time(uint64_t time) {
72
 
73 12 zero_gravi
  union {
74
    uint64_t uint64;
75
    uint32_t uint32[sizeof(uint64_t)/2];
76
  } cycles;
77
 
78
  cycles.uint64 = time;
79
 
80
  MTIME_LO = 0;
81
  MTIME_HI = cycles.uint32[1];
82
  MTIME_LO = cycles.uint32[0];
83
 
84 11 zero_gravi
}
85
 
86
 
87
/**********************************************************************//**
88
 * Get current system time.
89
 *
90
 * @note The MTIME timer increments with the primary processor clock.
91
 *
92 2 zero_gravi
 * @return Current system time (uint64_t)
93
 **************************************************************************/
94
uint64_t neorv32_mtime_get_time(void) {
95
 
96 12 zero_gravi
  union {
97
    uint64_t uint64;
98
    uint32_t uint32[sizeof(uint64_t)/2];
99
  } cycles;
100
 
101
  uint32_t tmp1, tmp2, tmp3;
102
  while(1) {
103
    tmp1 = MTIME_HI;
104
    tmp2 = MTIME_LO;
105
    tmp3 = MTIME_HI;
106
    if (tmp1 == tmp3) {
107
      break;
108
    }
109
  }
110
 
111
  cycles.uint32[0] = tmp2;
112
  cycles.uint32[1] = tmp3;
113
 
114
  return cycles.uint64;
115 2 zero_gravi
}
116
 
117
 
118
/**********************************************************************//**
119
 * Set compare time register (MTIMECMP) for generating interrupts.
120
 *
121
 * @note The interrupt is triggered when MTIME >= MTIMECMP.
122
 * @note The interrupt is acknwoledged by writing to the MTIMECMP.HI register.
123
 * @note The timer interrupt is enabled via neorv32_cpu_mti_enable(void) and disabled via neorv32_cpu_mti_disable(void).
124
 * @note Global interrupts have to be enabled via neorv32_cpu_eint(void).
125
 *
126
 * @param[in] timecmp System time for interrupt (uint64_t)
127
 **************************************************************************/
128
void neorv32_mtime_set_timecmp(uint64_t timecmp) {
129
 
130 4 zero_gravi
  MTIMECMP_LO = -1; // prevent mtimecmp from temporarily becoming smaller than the lesser of the old and new values
131 2 zero_gravi
  MTIMECMP = timecmp;
132
}
133
 
134
 
135
/**********************************************************************//**
136
 * Get compare time register (MTIMECMP).
137
 *
138
 * @return Current MTIMECMP value.
139
 **************************************************************************/
140
uint64_t neorv32_mtime_get_timecmp(void) {
141
 
142
  return MTIMECMP;
143
}

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.