Martin Vychodil f27c9c5139 esp32c3: memprot API upgrade and test application 5 years ago
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include 586023790e esp_system: move sleep modes to esp_hw_support, power down light sleep to esp_pm 4 years ago
port f27c9c5139 esp32c3: memprot API upgrade and test application 4 years ago
test c112bd8b57 esp_system: move intr_alloc 4 years ago
CMakeLists.txt 38d9251bda sleep: disable switch-case jump tables from being placed in flash 4 years ago
Kconfig 586023790e esp_system: move sleep modes to esp_hw_support, power down light sleep to esp_pm 4 years ago
README.md 32aa5f7e25 esp_system: add notes on timekeeping 4 years ago
app.lf bbc599493e esp32: move common fragment definitions 4 years ago
component.mk 586023790e esp_system: move sleep modes to esp_hw_support, power down light sleep to esp_pm 4 years ago
crosscore_int.c 393bd64a1e esp32: move crosscore int 4 years ago
dbg_stubs.c 5a56f794ec esp_common: move dbg stubs 5 years ago
esp_err.c c16ceafa5c esp_common: move esp_err 5 years ago
esp_system.c a7bac58480 esp32: move system api to esp_system 4 years ago
fpga_overrides.c 349f0cad3e esp_common: other movements 5 years ago
freertos_hooks.c 0e0914476c esp_common: move freertos hooks 5 years ago
int_wdt.c deaad431f4 esp_common: move task, int wdt 5 years ago
linker.lf a7bac58480 esp32: move system api to esp_system 4 years ago
panic.c 51e66d0f82 esp_common: move configs 5 years ago
sdkconfig.rename 51e66d0f82 esp_common: move configs 5 years ago
stack_check.c 883aba20be esp_common: move stack check 5 years ago
startup.c 94ac251091 Merge branch 'doc/general_notes' into 'master' 4 years ago
system_time.c 5228d9f9ce esp32c3: Apply one-liner/small changes for ESP32-C3 5 years ago
task_wdt.c a90f29fced wdt: Updates 4 years ago

README.md

System Notes

Timekeeping

The following are the timekeeping mechanisms available and their differences:

  1. System time (esp_system_get_time)

Time with the origin at g_startup_time. The implementation is not handled by esp_system, but it does provide a default implementation using RTC timer. Currently, esp_timer provides system time, since the hardware timers are under the control of that component. However, no matter the underlying timer, the system time provider should maintain the definition of having the origin point at g_startup_time.

  1. esp_timer time (esp_timer_get_time)

This is the time read from an underlying hardware timer, controlled through config. Origin is at the point where the underlying timer starts counting.

  1. newlib time (gettimeofday)

Timekeeping function in standard library. Can be set (settimeofday) or moved forward/backward (adjtime); with the possibility of the changes being made persistent through config. Currently implemented in terms of system time, as the point of origin is fixed. If persistence is enabled, RTC time is also used in conjuction with system time.

  1. RTC time (esp_rtc_get_time_us)

Time read from RTC timer.