Rmt Architecture - Espressif Systems ESP32 Technical Reference Manual

6 REMOTE CONTROLLER PERIPHERAL
6. Remote Controller Peripheral
6.1 Introduction
The RMT (Remote Control) module is primarily designed to send and receive infrared remote control signals that
use on-off-keying of a carrier frequency, but due to its design it can be used to generate various types of signals.
An RMT transmitter does this by reading consecutive duration values for an active and inactive output from the
built-in RAM block, optionally modulating it with a carrier wave. A receiver will inspect its input signal, optionally
filtering it, and will place the lengths of time the signal is active and inactive in the RAM block.
The RMT module has eight channels, numbered 0 to 7; registers, signals and blocks that are duplicated every
channel are indicated by an n as a placeholder for the channel number.
6.2 Functional Description

6.2.1 RMT Architecture

Figure 14: RMT Architecture
The RMT module contains eight channels; each channel has a transmitter and receiver, of which one can be
active per channel. The 8 channels share a 512x32-bit RAM block which can be read and written by the
processor cores over the APB bus, as well as read by the transmitters and written by the receivers. The
transmitted signal can optionally be modulated by a carrier wave. Each channel is clocked by a divided-down
signal derived from either the APB bus clock or REF_TICK.
Espressif Systems 81 ESP32 Technical Reference Manual V1.0