esp-idf/components/esp_hal_rtc_timer/README.md

ESP Hardware Abstraction Layer for RTC Timer Peripherals

Note

This component is currently in beta. Its API, behavior, and compatibility may change at any time and without notice; backward compatibility is not guaranteed. Use caution when integrating into production systems.

Overview

The esp_hal_rtc_timer component provides a unified Hardware Abstraction Layer for RTC Timer peripherals across all ESP-IDF supported targets. This HAL abstracts hardware differences between legacy RTC timer implementations (in RTC_CNTL peripheral) and modern low-power timer implementations, providing a consistent API for wakeup timer configuration and RTC time reading across different ESP chip families.

The component consolidates timer functionality from two different hardware implementations:

• SOC_RTC_TIMER_V1_SUPPORTED: Legacy RTC timer functionality in RTC_CNTL peripheral (ESP32, ESP32C2, ESP32C3, ESP32S2, ESP32S3)
• SOC_RTC_TIMER_V2_SUPPORTED: Newer LP timer peripheral (ESP32C5, ESP32C6, ESP32C61, ESP32H2, ESP32H21, ESP32H4, ESP32P4)

Unified HAL API (All Chips)

• Wakeup timer configuration via rtc_timer_hal_set_wakeup_time()
• RTC time reading via rtc_timer_hal_get_cycle_count()

Hardware-Specific LL API

• V1 Chips: Direct register access in RTC_CNTL peripheral
• V2 Chips: LP Timer peripheral with alarm target configuration and counter snapshot operations

Please note that the interfaces provided by this component are internal to ESP-IDF and are subject to change.