1 /*
2  * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
3  *
4  * SPDX-License-Identifier: Apache-2.0
5  */
6 
7 #include "stubs.h"
8 #include "esp_private/systimer.h"
9 
10 /**
11  * @brief systimer's clock source is fixed to XTAL (40MHz/26MHz), and has a fixed fractional divider (2.5).
12  *        So the resolution of the systimer is 40MHz/2.5 = 16MHz, or 26MHz/2.5 = 10.4MHz.
13  */
14 
15 #if CONFIG_XTAL_FREQ == 40
systimer_ticks_to_us(uint64_t ticks)16 uint64_t systimer_ticks_to_us(uint64_t ticks)
17 {
18     return ticks / 16;
19 }
20 
systimer_us_to_ticks(uint64_t us)21 uint64_t systimer_us_to_ticks(uint64_t us)
22 {
23     return us * 16;
24 }
25 #elif CONFIG_XTAL_FREQ == 26
systimer_ticks_to_us(uint64_t ticks)26 uint64_t systimer_ticks_to_us(uint64_t ticks)
27 {
28     return ticks * 5 / 52;
29 }
30 
systimer_us_to_ticks(uint64_t us)31 uint64_t systimer_us_to_ticks(uint64_t us)
32 {
33     return us * 52 / 5;
34 }
35 #else
36 #error "Unsupported XTAL frequency by systimer"
37 #endif
38