fn rtc_sleep_pu() {
    LPWR::regs()
        .dig_pwc()
        .modify(|_, w| w.lslp_mem_force_pu().clear_bit());

    APB_CTRL::regs().front_end_mem_pd().modify(|_, w| {
        w.dc_mem_force_pu().clear_bit();
        w.pbus_mem_force_pu().clear_bit();
        w.agc_mem_force_pu().clear_bit()
    });
    APB_CTRL::regs().mem_power_up().modify(|_, w| unsafe {
        w.sram_power_up().bits(0u8);
        w.rom_power_up().bits(0u8)
    });
}
Configure whether certain peripherals are powered down in deep sleep
esp-hal/src/rtc_cntl/rtc/esp32c2.rs