esp_idf_sys

Constant soc_periph_systimer_clk_src_t_SYSTIMER_CLK_SRC_XTAL

Source 
pub const soc_periph_systimer_clk_src_t_SYSTIMER_CLK_SRC_XTAL: soc_periph_systimer_clk_src_t = 10;
Expand description

< SYSTIMER source clock is XTAL