Paparazzi UAS  v5.2.2_stable-0-gd6b9f29
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sys_time_arch.h
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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 #ifdef RTOS_IS_CHIBIOS
42 #include "chibios_stub.h"
43 #include "chconf.h"
44 #endif
45 
51 static inline uint32_t get_sys_time_usec(void) {
52 #ifdef RTOS_IS_CHIBIOS
53  return (chibios_chTimeNow() * (1000000 / CH_FREQUENCY));
54 #else
55  return sys_time.nb_sec * 1000000 +
57  usec_of_cpu_ticks(systick_get_reload() - systick_get_value());
58 #endif
59 }
60 
65 static inline uint32_t get_sys_time_msec(void) {
66 #ifdef RTOS_IS_CHIBIOS
67  return (chibios_chTimeNow() * (1000 / CH_FREQUENCY));
68 #else
69  return sys_time.nb_sec * 1000 +
71  msec_of_cpu_ticks(systick_get_reload() - systick_get_value());
72 #endif
73 }
74 
75 
81 static inline void sys_time_usleep(uint32_t us) {
82 #ifdef RTOS_IS_CHIBIOS
83  chibios_chThdSleepMicroseconds (us);
84 #else
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  }
98  else {
99  // one more count flag is required
100  n++;
101  end = systick_get_reload() - rem + start;
102  }
103  // count number of cycles (when counter reachs 0)
104  while (n) {
105  while (!systick_get_countflag());
106  n--;
107  }
108  // wait remaining ticks
109  while (systick_get_value() > end);
110 #endif
111 }
112 
113 #endif /* SYS_TIME_ARCH_H */
static uint32_t msec_of_cpu_ticks(uint32_t cpu_ticks)
Definition: sys_time.h:176
static void sys_time_usleep(uint32_t us)
Busy wait in microseconds.
Definition: sys_time_arch.h:81
static uint32_t get_sys_time_usec(void)
Get the time in microseconds since startup.
Definition: sys_time_arch.h:51
static uint32_t usec_of_cpu_ticks(uint32_t cpu_ticks)
Definition: sys_time.h:180
static uint32_t get_sys_time_msec(void)
Get the time in milliseconds since startup.
Definition: sys_time_arch.h:65
Architecture independent timing functions.
unsigned long uint32_t
Definition: types.h:18
volatile uint32_t nb_sec_rem
remainder of seconds since startup in CPU_TICKS
Definition: sys_time.h:70
volatile uint32_t nb_sec
full seconds since startup
Definition: sys_time.h:69
static uint32_t cpu_ticks_of_usec(uint32_t usec)
Definition: sys_time.h:164