ESP Hardware Abstraction Layer for I2S Peripheral(s)

[!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_i2s component provides a Hardware Abstraction Layer for Inter-IC Sound (I2S) controllers across all ESP-IDF supported targets. I2S is a serial bus interface standard used for connecting digital audio devices, enabling high-quality audio data transmission between integrated circuits.

Architecture

The I2S HAL is structured in two main sub-layers:

1. HAL Layer (Upper): Defines the operational steps and data structures required to control I2S peripherals (e.g., initialization, clock configuration, STD/TDM/PDM slot configuration, channel enable/disable).

2. Low-Level Layer (Bottom): Serves as a translation layer between the HAL and the register files defined in the soc component, handling target-specific register configurations.

Supported I2S Controllers

This HAL supports two I2S controller types depending on the ESP chip:

• Standard I2S: Traditional I2S interface supporting master/slave modes. And the different hardware versions are supported regarding different chips.
• Low-Power I2S (LP I2S): Power-efficient I2S controller for low-power applications (on supported chips)

Features

• Multiple Audio Formats:
  • Standard I2S (STD) mode
  • Pulse Density Modulation (PDM) mode
  • Time Division Multiplexing (TDM) mode
• Master/Slave Mode Support: Configurable as master or slave device
• Bidirectional Communication: Independent TX and RX channel configuration
• Clock Configuration: Precise master clock (MCLK) and bit clock (BCLK) division
• Slot Configuration: Mono/stereo mode, slot selection, bit width configuration
• PDM/PCM Converter Features: PCM-to-PDM and PDM-to-PCM conversion, high-pass filtering (on supported chips)
• TDM Features: Multi-slot TDM support with configurable slot masks
• Signal Connection Management: GPIO signal mapping and interrupt configuration

Usage

The HAL functions primarily serve ESP-IDF peripheral drivers such as esp_driver_i2s.

Advanced developers can use these interfaces directly when implementing custom drivers, with the understanding that API stability is not guaranteed.

Dependencies

• soc: Provides chip-specific register definitions
• hal: Core hardware abstraction utilities and macros