Paparazzi UAS  v5.8.2_stable-0-g6260b7c
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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 {
53 #ifdef RTOS_IS_CHIBIOS
54  return (chibios_chTimeNow() * (1000000 / CH_FREQUENCY));
55 #else
56  return sys_time.nb_sec * 1000000 +
58  usec_of_cpu_ticks(systick_get_reload() - systick_get_value());
59 #endif
60 }
61 
66 static inline uint32_t get_sys_time_msec(void)
67 {
68 #ifdef RTOS_IS_CHIBIOS
69  return (chibios_chTimeNow() * (1000 / CH_FREQUENCY));
70 #else
71  return sys_time.nb_sec * 1000 +
73  msec_of_cpu_ticks(systick_get_reload() - systick_get_value());
74 #endif
75 }
76 
77 
83 static inline void sys_time_usleep(uint32_t us)
84 {
85 #ifdef RTOS_IS_CHIBIOS
86  chibios_chThdSleepMicroseconds(us);
87 #else
88  // start time
89  uint32_t start = systick_get_value();
90  // max time of one full counter cycle (n + 1 ticks)
91  uint32_t DT = usec_of_cpu_ticks(systick_get_reload() + 1);
92  // number of cycles
93  uint32_t n = us / DT;
94  // remaining number of cpu ticks
95  uint32_t rem = cpu_ticks_of_usec(us % DT);
96  // end time depend on the current value of the counter
97  uint32_t end;
98  if (rem < start) {
99  end = start - rem;
100  } else {
101  // one more count flag is required
102  n++;
103  end = systick_get_reload() - rem + start;
104  }
105  // count number of cycles (when counter reachs 0)
106  while (n) {
107  while (!systick_get_countflag());
108  n--;
109  }
110  // wait remaining ticks
111  while (systick_get_value() > end);
112 #endif
113 }
114 
115 #endif /* SYS_TIME_ARCH_H */
static uint32_t msec_of_cpu_ticks(uint32_t cpu_ticks)
Definition: sys_time.h:188
static void sys_time_usleep(uint32_t us)
Busy wait in microseconds.
Definition: sys_time_arch.h:83
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:193
static uint32_t get_sys_time_msec(void)
Get the time in milliseconds since startup.
Definition: sys_time_arch.h:66
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:173