# ATmega328

> single-chip microcontroller in the megaAVR family, created by Atmel

**Wikidata**: [Q4654963](https://www.wikidata.org/wiki/Q4654963)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/ATmega328)  
**Source**: https://4ort.xyz/entity/atmega328

## Summary
ATmega328 is a single-chip microcontroller from Atmel's megaAVR family, best known as the processor in the Arduino Uno board. It features 32 KB of flash memory and 2 KB of SRAM, using an 8-bit RISC architecture with a modified Harvard design. This chip is widely used in embedded systems, hobbyist projects, and educational contexts due to its versatility and integration with the Arduino platform.

## Key Facts
- **Manufacturer**: Atmel (acquired by Microchip Technology in 2016).
- **Family**: Part of the Atmel AVR family of 8-bit RISC microcontrollers.
- **Architecture**: Modified Harvard architecture; 8-bit RISC instruction set with single-cycle execution for most instructions.
- **Memory**: 32 KB flash memory, 2 KB SRAM, 1 KB EEPROM.
- **Notable Variant**: ATmega328P is the core component of the Arduino Uno.
- **Applications**: Embedded systems, robotics, automotive controls, consumer electronics, and educational platforms.
- **Classifications**: Subclass of microcontroller and computing platform; Dewey Decimal Classification 004.165, 621.3916; Library of Congress Authority ID sh2008020007.
- **Identifiers**: GND ID 4540630-3; Wikidata Q482825; Wikipedia title "ATmega328"; Commons category ATmega328; Freebase ID /m/0ndhr3x.
- **Sitelink Count**: 8 (across Wikimedia projects).
- **Aliases**: Commonly referred to as Atmega328.
- **Used By**: Arduino (specifically Arduino Uno).
- **Instance Of**: Atmel AVR microcontroller.

## FAQs
**Q: Who manufactures the ATmega328 microcontroller?**  
A: The ATmega328 is manufactured by Atmel, which was acquired by Microchip Technology in 2016. Production continues under Microchip's branding and support.

**Q: What is the ATmega328 commonly used for?**  
A: It is widely used in embedded systems, particularly as the processor in Arduino Uno boards. Applications include robotics, consumer electronics, automotive controls, and educational projects for teaching programming and electronics.

**Q: What are the key specifications of the ATmega328?**  
A: The ATmega328 has 32 KB of flash memory for program storage, 2 KB of SRAM for data, and 1 KB of EEPROM. It operates on an 8-bit RISC architecture with a modified Harvard design, enabling efficient performance in low-power and real-time applications.

**Q: How is the ATmega328 related to Arduino?**  
A: The ATmega328P variant is the central microcontroller in the Arduino Uno, the flagship board of the Arduino project. This integration has made the ATmega328 a cornerstone of the maker community, with extensive libraries and shields built around it.

**Q: What architecture does the ATmega328 use?**  
A: It uses a modified Harvard architecture, which allows simultaneous access to program and data memory. Combined with an 8-bit RISC instruction set, this design optimizes speed and power efficiency for embedded tasks.

## Why It Matters
The ATmega328 matters because it democratized embedded systems development through its role in the Arduino Uno. By providing an affordable, easy-to-use platform, it enabled millions of hobbyists, students, and makers to create interactive projects without deep electronics knowledge. Its robust design, with sufficient memory and peripherals for many applications, made it a standard in prototyping and small-scale IoT devices. The chip's reliability and extensive community support accelerated innovation in fields like robotics, home automation, and education, cementing its place as a foundational component in modern embedded technology.

## Notable For
- **Arduino Uno Core**: The ATmega328P is the defining microcontroller of the Arduino Uno, the world's most popular prototyping board.
- **Memory Configuration**: Offers 32 KB flash and 2 KB SRAM, a balanced specification for its class that supports complex sketches while remaining cost-effective.
- **RISC Efficiency**: As an 8-bit RISC chip, it executes most instructions in a single cycle, optimizing speed and power consumption.
- **Modified Harvard Architecture**: Enables concurrent instruction and data access, improving throughput for real-time applications.
- **Educational Impact**: Central to countless STEM programs and DIY projects, lowering the barrier to entry for embedded programming.
- **Longevity and Support**: Despite newer models, the ATmega328 remains in high demand due to Arduino's ecosystem and extensive documentation.

## Body
### History and Development
The ATmega328 was developed by Atmel as part of their megaAVR series within the broader AVR microcontroller family. Atmel, later acquired by Microchip Technology in 2016, designed the AVR line based on RISC principles to create efficient, easy-to-program chips. The ATmega328 emerged as a mid-range model, offering more memory and peripherals than earlier AVRs like the ATmega16, while maintaining compatibility with the AVR toolchain.

### Technical Architecture
The ATmega328 employs an 8-bit RISC architecture with a modified Harvard design. This allows the CPU to access program memory and data memory simultaneously, enhancing performance. Key specifications include:
- **Flash Memory**: 32 KB for storing program code.
- **SRAM**: 2 KB for runtime data.
- **EEPROM**: 1 KB for non-volatile data storage.
- **Peripherals**: As an AVR family member, it integrates timers, analog-to-digital converters (ADCs), and communication interfaces (UART, SPI, I²C), enabling direct interfacing with sensors, displays, and other hardware.
- **Clock Speed**: Typically operates up to 20 MHz (implied by AVR family standards, though not explicitly stated for ATmega328 alone).

### Role in the Arduino Ecosystem
The ATmega328P variant is the heart of the Arduino Uno, the flagship board of the Arduino project. This integration is pivotal because:
- Arduino's simplified programming environment, based on Wiring and later the Arduino IDE, abstracts low-level complexities, making the ATmega328 accessible to non-engineers.
- The Uno's popularity drove massive production volumes, reducing costs and ensuring wide availability of the chip.
- A vast ecosystem of shields, libraries, and tutorials centers around the ATmega328, creating a self-sustaining community that fuels continuous innovation.

### Applications and Use Cases
Beyond Arduino, the ATmega328 is used in:
- **Consumer Electronics**: Simple devices like remote controls, toys, and appliances where cost and power efficiency are critical.
- **Industrial Control**: Sensor interfaces, motor drivers, and data loggers in manufacturing and automation.
- **Robotics**: As the brain for small to medium robots, leveraging its GPIOs and communication interfaces.
- **Education**: In schools and universities for teaching embedded systems and programming, often through Arduino-based curricula.

### Identifiers and Classifications
The ATmega328 is recognized in various knowledge systems:
- **Library of Congress**: Dewey Decimal Classification 004.165, 621.3916; Authority ID sh2008020007.
- **Authority IDs**: GND ID 4540630-3; Wikidata Q482825.
- **Wikipedia**: Article titled "ATmega328" available in multiple languages (commons, cs, en, es, hu, pt, ro, zh).
- **Commons Category**: ATmega328 on Wikimedia Commons, hosting images like the chip's pinout diagram.
- **Freebase ID**: /m/0ndhr3x.
- **Sitelink Count**: 8, indicating cross-wiki presence.

### Relationship to Other AVR Models
Within the megaAVR family, the ATmega328 sits between entry-level models like ATmega88 (8 KB flash) and high-end variants like ATmega2560 (256 KB flash). Its 32 KB flash size made it a sweet spot for many projects, contributing to its adoption in Arduino Uno. Other notable models include ATmega16 (16 KB flash) for industrial uses and ATmega88 for low-power battery applications.

### Legacy and Continued Relevance
Despite the introduction of more powerful microcontrollers, the ATmega328 remains relevant due to:
- **Stability**: Proven design with few errata, ideal for production environments.
- **Toolchain Support**: Mature GCC-based compilers and debugging tools.
- **Community Knowledge**: Decades of accumulated projects, forums, and documentation.
- **Cost**: Low unit price, especially in volume, making it economical for mass-produced devices.
- **Cultural Footprint**: Recognized in academic and technical literature, with a lasting impact on the maker movement and IoT development.