Data Sheet
Table Of Contents
- 1 Overview
- 2 Pin Definitions
- 3 Functional Description
- 4 Peripherals and Sensors
- 4.1 Descriptions of Peripherals and Sensors
- 4.1.1 General Purpose Input / Output Interface (GPIO)
- 4.1.2 Analog-to-Digital Converter (ADC)
- 4.1.3 Hall Sensor
- 4.1.4 Digital-to-Analog Converter (DAC)
- 4.1.5 Touch Sensor
- 4.1.6 Ultra-Low-Power Co-processor
- 4.1.7 Ethernet MAC Interface
- 4.1.8 SD/SDIO/MMC Host Controller
- 4.1.9 SDIO/SPI Slave Controller
- 4.1.10 Universal Asynchronous Receiver Transmitter (UART)
- 4.1.11 I²C Interface
- 4.1.12 I²S Interface
- 4.1.13 Infrared Remote Controller
- 4.1.14 Pulse Counter
- 4.1.15 Pulse Width Modulation (PWM)
- 4.1.16 LED PWM
- 4.1.17 Serial Peripheral Interface (SPI)
- 4.1.18 Accelerator
- 4.2 Peripheral Pin Configurations
- 4.1 Descriptions of Peripherals and Sensors
- 5 Electrical Characteristics
- 6 Package Information
- 7 Part Number and Ordering Information
- 8 Learning Resources
- Appendix A – ESP32 Pin Lists
- Revision History
3 Functional Description
Category Target Start Address End Address Size
Peripheral
SYSCON 0x3FF6_6000 0x3FF6_6FFF 4 KB
I2C1 0x3FF6_7000 0x3FF6_7FFF 4 KB
SDMMC 0x3FF6_8000 0x3FF6_8FFF 4 KB
EMAC 0x3FF6_9000 0x3FF6_AFFF 8 KB
PWM1 0x3FF6_C000 0x3FF6_CFFF 4 KB
I2S1 0x3FF6_D000 0x3FF6_DFFF 4 KB
UART2 0x3FF6_E000 0x3FF6_EFFF 4 KB
PWM2 0x3FF6_F000 0x3FF6_FFFF 4 KB
PWM3 0x3FF7_0000 0x3FF7_0FFF 4 KB
RNG 0x3FF7_5000 0x3FF7_5FFF 4 KB
3.2 Timers and Watchdogs
3.2.1 64bit Timers
There are four general-purpose timers embedded in the chip. They are all 64-bit generic timers which are based
on 16-bit prescalers and 64-bit auto-reload-capable up/down-timers.
The timers feature:
• A 16-bit clock prescaler, from 2 to 65536
• A 64-bit timer
• Configurable up/down timer: incrementing or decrementing
• Halt and resume of time-base counter
• Auto-reload at alarming
• Software-controlled instant reload
• Level and edge interrupt generation
3.2.2 Watchdog Timers
The chip has three watchdog timers: one in each of the two timer modules (called the Main Watchdog Timer, or
MWDT) and one in the RTC module (called the RTC Watchdog Timer, or RWDT). These watchdog timers are
intended to recover from an unforeseen fault causing the application program to abandon its normal sequence. A
watchdog timer has four stages. Each stage may trigger one of three or four possible actions upon the expiry of
its programmed time period, unless the watchdog is fed or disabled. The actions are: interrupt, CPU reset, core
reset, and system reset. Only the RWDT can trigger the system reset, and is able to reset the entire chip,
including the RTC itself. A timeout value can be set for each stage individually.
During flash boot the RWDT and the first MWDT start automatically in order to detect, and recover from, booting
problems.
The watchdogs have the following features:
• Four stages, each of which can be configured or disabled separately
• A programmable time period for each stage
Espressif Systems 25
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ESP32 Series Datasheet v3.5