blob: a48f3f79cfd05812461f1d167441323918a47e9c (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
|
/**
* Marlin 3D Printer Firmware
* Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
*
* Based on Sprinter and grbl.
* Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*
*/
#pragma once
/**
* Busy wait delay cycles routines:
*
* DELAY_CYCLES(count): Delay execution in cycles
* DELAY_NS(count): Delay execution in nanoseconds
* DELAY_US(count): Delay execution in microseconds
*/
#include "../../core/macros.h"
#if defined(__arm__) || defined(__thumb__)
#if __CORTEX_M == 7
// Cortex-M3 through M7 can use the cycle counter of the DWT unit
// https://www.anthonyvh.com/2017/05/18/cortex_m-cycle_counter/
FORCE_INLINE static void enableCycleCounter() {
CoreDebug->DEMCR |= CoreDebug_DEMCR_TRCENA_Msk;
#if __CORTEX_M == 7
DWT->LAR = 0xC5ACCE55; // Unlock DWT on the M7
#endif
DWT->CYCCNT = 0;
DWT->CTRL |= DWT_CTRL_CYCCNTENA_Msk;
}
FORCE_INLINE volatile uint32_t getCycleCount() { return DWT->CYCCNT; }
FORCE_INLINE static void DELAY_CYCLES(const uint32_t x) {
const uint32_t endCycles = getCycleCount() + x;
while (PENDING(getCycleCount(), endCycles)) {}
}
#else
// https://blueprints.launchpad.net/gcc-arm-embedded/+spec/delay-cycles
#define nop() __asm__ __volatile__("nop;\n\t":::)
FORCE_INLINE static void __delay_4cycles(uint32_t cy) { // +1 cycle
#if ARCH_PIPELINE_RELOAD_CYCLES < 2
#define EXTRA_NOP_CYCLES A("nop")
#else
#define EXTRA_NOP_CYCLES ""
#endif
__asm__ __volatile__(
A(".syntax unified") // is to prevent CM0,CM1 non-unified syntax
L("1")
A("subs %[cnt],#1")
EXTRA_NOP_CYCLES
A("bne 1b")
: [cnt]"+r"(cy) // output: +r means input+output
: // input:
: "cc" // clobbers:
);
}
// Delay in cycles
FORCE_INLINE static void DELAY_CYCLES(uint32_t x) {
if (__builtin_constant_p(x)) {
#define MAXNOPS 4
if (x <= (MAXNOPS)) {
switch (x) { case 4: nop(); case 3: nop(); case 2: nop(); case 1: nop(); }
}
else { // because of +1 cycle inside delay_4cycles
const uint32_t rem = (x - 1) % (MAXNOPS);
switch (rem) { case 3: nop(); case 2: nop(); case 1: nop(); }
if ((x = (x - 1) / (MAXNOPS)))
__delay_4cycles(x); // if need more then 4 nop loop is more optimal
}
#undef MAXNOPS
}
else if ((x >>= 2))
__delay_4cycles(x);
}
#undef nop
#endif
#elif defined(__AVR__)
#define nop() __asm__ __volatile__("nop;\n\t":::)
FORCE_INLINE static void __delay_4cycles(uint8_t cy) {
__asm__ __volatile__(
L("1")
A("dec %[cnt]")
A("nop")
A("brne 1b")
: [cnt] "+r"(cy) // output: +r means input+output
: // input:
: "cc" // clobbers:
);
}
// Delay in cycles
FORCE_INLINE static void DELAY_CYCLES(uint16_t x) {
if (__builtin_constant_p(x)) {
#define MAXNOPS 4
if (x <= (MAXNOPS)) {
switch (x) { case 4: nop(); case 3: nop(); case 2: nop(); case 1: nop(); }
}
else {
const uint32_t rem = (x) % (MAXNOPS);
switch (rem) { case 3: nop(); case 2: nop(); case 1: nop(); }
if ((x = (x) / (MAXNOPS)))
__delay_4cycles(x); // if need more then 4 nop loop is more optimal
}
#undef MAXNOPS
}
else if ((x >>= 2))
__delay_4cycles(x);
}
#undef nop
#elif defined(__PLAT_LINUX__) || defined(ESP32)
// specified inside platform
#else
#error "Unsupported MCU architecture"
#endif
// Delay in nanoseconds
#define DELAY_NS(x) DELAY_CYCLES((x) * ((F_CPU) / 1000000UL) / 1000UL)
// Delay in microseconds
#define DELAY_US(x) DELAY_CYCLES((x) * ((F_CPU) / 1000000UL))
|
