Help¶

If your CPU supports invariant TSC, and you know the ratio of the TSC frequency to CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC (the local APIC timer frequency), then enable this for a much faster and more accurate z_timer_cycle_get_32().

Direct dependencies¶

(APIC_TIMER && SOC_APOLLO_LAKE) || APIC_TIMER

(Includes any dependencies from ifs and menus.)

Default¶

y

Kconfig definitions¶

At <Zephyr>/soc/x86/apollo_lake/Kconfig.defconfig:29

Included via <Zephyr>/Kconfig:8 → <Zephyr>/Kconfig.zephyr:25 → <BuildDir>/Kconfig/Kconfig.soc.defconfig:1

Menu path: (Top)

config APIC_TIMER_TSC
    bool
    default y
    depends on APIC_TIMER && SOC_APOLLO_LAKE

At <Zephyr>/drivers/timer/Kconfig:34

Included via <Zephyr>/Kconfig:8 → <Zephyr>/Kconfig.zephyr:32 → <Zephyr>/drivers/Kconfig:28

Menu path: (Top) → Device Drivers → Timer Drivers → New local APIC timer

config APIC_TIMER_TSC
    bool "Use invariant TSC for z_timer_cycle_get_32()"
    depends on APIC_TIMER
    help
      If your CPU supports invariant TSC, and you know the ratio of the
      TSC frequency to CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC (the local APIC
      timer frequency), then enable this for a much faster and more
      accurate z_timer_cycle_get_32().

(The ‘depends on’ condition includes propagated dependencies from ifs and menus.)