Paparazzi UAS  v7.0_unstable
Paparazzi is a free software Unmanned Aircraft System.
sys_time_arch.h
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1 /*
2  *
3  * Copyright (C) 2009-2011 The Paparazzi Team
4  *
5  * This file is part of paparazzi.
6  *
7  * paparazzi is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
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15  * GNU General Public License for more details.
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22  */
23 
32 #ifndef SYS_TIME_ARCH_H
33 #define SYS_TIME_ARCH_H
34 
35 #include "mcu_periph/sys_time.h"
36 
37 #include <libopencm3/stm32/gpio.h>
38 #include <libopencm3/stm32/rcc.h>
39 #include <libopencm3/cm3/systick.h>
40 #include "std.h"
41 
47 static inline uint32_t get_sys_time_usec(void)
48 {
49  return sys_time.nb_sec * 1000000 +
51  usec_of_cpu_ticks(systick_get_reload() - systick_get_value());
52 }
53 
59 static inline uint32_t get_sys_time_usec100(void)
60 {
61  return sys_time.nb_sec * 10000 +
63  usec_of_cpu_ticks(systick_get_reload() - systick_get_value())/100;
64 }
65 
70 static inline uint32_t get_sys_time_msec(void)
71 {
72  return sys_time.nb_sec * 1000 +
74  msec_of_cpu_ticks(systick_get_reload() - systick_get_value());
75 }
76 
77 
83 static inline void sys_time_usleep(uint32_t us)
84 {
85  // start time
86  uint32_t start = systick_get_value();
87  // max time of one full counter cycle (n + 1 ticks)
88  uint32_t DT = usec_of_cpu_ticks(systick_get_reload() + 1);
89  // number of cycles
90  uint32_t n = us / DT;
91  // remaining number of cpu ticks
92  uint32_t rem = cpu_ticks_of_usec(us % DT);
93  // end time depend on the current value of the counter
94  uint32_t end;
95  if (rem < start) {
96  end = start - rem;
97  } else {
98  // one more count flag is required
99  n++;
100  end = systick_get_reload() - rem + start;
101  }
102  // count number of cycles (when counter reachs 0)
103  while (n) {
104  while (!systick_get_countflag());
105  n--;
106  }
107  // wait remaining ticks
108  while (systick_get_value() > end);
109 }
110 
111 #endif /* SYS_TIME_ARCH_H */
void sys_time_usleep(uint32_t us)
sys_time_usleep(uint32_t us)
uint32_t get_sys_time_usec100(void)
Get the time in microseconds divided by 100 since startup.
Definition: sys_time_arch.c:87
uint32_t get_sys_time_usec(void)
Get the time in microseconds since startup.
Definition: sys_time_arch.c:71
uint32_t get_sys_time_msec(void)
Get the time in milliseconds since startup.
Definition: sys_time_arch.c:98
Architecture independent timing functions.
static uint32_t msec_of_cpu_ticks(uint32_t cpu_ticks)
Definition: sys_time.h:202
volatile uint32_t nb_sec
full seconds since startup
Definition: sys_time.h:72
volatile uint32_t nb_sec_rem
remainder of seconds since startup in CPU_TICKS
Definition: sys_time.h:73
static uint32_t cpu_ticks_of_usec(uint32_t usec)
Definition: sys_time.h:187
static uint32_t usec_of_cpu_ticks(uint32_t cpu_ticks)
Definition: sys_time.h:207
unsigned int uint32_t
Typedef defining 32 bit unsigned int type.
Definition: vl53l1_types.h:78