esp-idf/components/esp_system
Song Ruo Jing ea97cc93ea Merge branch 'feature/c2_systimer_26mhz' into 'master'
esp32c2: 26 MHz XTAL support: Kconfig option, systimer support

Closes IDF-5412 and IDF-5413

See merge request espressif/esp-idf!18835
2022-07-11 16:17:25 +08:00
..
include Fix datatype conversion compiler error #9254 2022-06-29 14:39:36 +02:00
ld (Xtensa) Build: add .xt.prop and .xt.lit to the compiled ELF file 2022-07-05 04:39:29 +00:00
port Merge branch 'feature/c2_systimer_26mhz' into 'master' 2022-07-11 16:17:25 +08:00
test clk_tree: Refactor rtc_clk.c by adding HAL layer for clock subsystem 2022-06-13 17:47:50 +08:00
test_apps ulp-riscv: add support for using ADC as well as an example show-casing it. 2022-07-11 09:31:22 +08:00
test_eh_frame_parser
CMakeLists.txt esp_psram: new psram component 2022-06-14 15:44:27 +08:00
Kconfig Kconfig: Update dependencies to avoid invalid configurations 2022-07-11 12:24:58 +08:00
README.md
app.lf
crosscore_int.c
debug_stubs.c
eh_frame_parser.c
esp_err.c spi_flash: Remove legacy spi_flash drivers 2022-07-01 11:01:34 +08:00
esp_ipc.c
esp_system.c
fpga_overrides.c
freertos_hooks.c
int_wdt.c
linker.lf
panic.c
sdkconfig.rename
sdkconfig.rename.esp32
sdkconfig.rename.esp32c3
sdkconfig.rename.esp32h2
sdkconfig.rename.esp32s2
sdkconfig.rename.esp32s3
stack_check.c
startup.c spi_flash: Remove legacy spi_flash drivers 2022-07-01 11:01:34 +08:00
system_time.c
task_wdt.c esp_system: TWDT needs to deregister idle hook callback on esp_task_wdt_deinit() 2022-07-05 13:40:46 +08:00
ubsan.c
xt_wdt.c esp_intr: Split RTC interrupt, making some of signals can be triggered with cache disabled 2022-06-02 10:38:55 +08:00

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.