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
|
/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
* Copyright (c) 2015 Daniel Campora
*
* 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.
*
* 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 "mpconfig.h"
#include MICROPY_HAL_H
#include "misc.h"
#include "nlr.h"
#include "qstr.h"
#include "obj.h"
#include "irq.h"
#include "pybsystick.h"
#include "systick.h"
#include "inc/hw_types.h"
#include "inc/hw_nvic.h"
#ifdef USE_FREERTOS
#include "FreeRTOS.h"
#include "task.h"
#endif
bool sys_tick_has_passed(uint32_t start_tick, uint32_t delay_ms) {
return HAL_GetTick() - start_tick >= delay_ms;
}
// waits until at least delay_ms milliseconds have passed from the sampling of
// startTick. Handles overflow properly. Assumes stc was taken from
// HAL_GetTick() some time before calling this function.
void sys_tick_wait_at_least(uint32_t start_tick, uint32_t delay_ms) {
#ifdef USE_FREERTOS
vTaskDelay (delay_ms / portTICK_PERIOD_MS);
#else
while (!sys_tick_has_passed(start_tick, delay_ms)) {
__WFI(); // enter sleep mode, waiting for interrupt
}
#endif
}
// The SysTick timer counts down at HAL_FCPU_HZ, so we can use that knowledge
// to grab a microsecond counter.
//
// We assume that HAL_GetTick returns milliseconds.
uint32_t sys_tick_get_microseconds(void) {
mp_uint_t irq_state = disable_irq();
uint32_t counter = SysTickValueGet();
uint32_t milliseconds = HAL_GetTick();
uint32_t status = (HWREG(NVIC_ST_CTRL));
enable_irq(irq_state);
// It's still possible for the countflag bit to get set if the counter was
// reloaded between reading VAL and reading CTRL. With interrupts disabled
// it definitely takes less than 50 HCLK cycles between reading VAL and
// reading CTRL, so the test (counter > 50) is to cover the case where VAL
// is +ve and very close to zero, and the COUNTFLAG bit is also set.
if ((status & NVIC_ST_CTRL_COUNT) && counter > 50) {
// This means that the HW reloaded VAL between the time we read VAL and the
// time we read CTRL, which implies that there is an interrupt pending
// to increment the tick counter.
milliseconds++;
}
uint32_t load = (HWREG(NVIC_ST_RELOAD));
counter = load - counter; // Convert from decrementing to incrementing
// ((load + 1) / 1000) is the number of counts per microsecond.
//
// counter / ((load + 1) / 1000) scales from the systick clock to microseconds
// and is the same thing as (counter * 1000) / (load + 1)
return milliseconds * 1000 + (counter * 1000) / (load + 1);
}
|
