ATMEGA1284P-MUR - 8-bit AVR MCU 20MHz 128KB Flash | Microchip
MPN: ATMEGA1284P-MUR β Active| Qty | Unit Price | Extended |
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| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
ATMEGA1284P-MUR Overview
An 8-bit microcontroller is an integrated circuit that executes program instructions and controls peripherals using an 8-bit-wide data path. The AVR family from Atmel (now Microchip) uses an enhanced RISC architecture in which most instructions execute in a single clock cycle, placing the ATmega1284P in the hierarchy: microcontroller -> 8-bit MCU -> AVR ATmega family -> embedded processing and power management of a complete system on a single chip.
Key features include 128 KB of self-programmable Flash with Read-While-Write support, 131 powerful instructions most of which execute in one cycle, 32 x 8 general-purpose working registers, and an on-chip 2-cycle hardware multiplier. The PicoPower-qualified design delivers low active and sleep-mode currents, making the picoPower P suffix meaningful for battery-powered designs.
The peripheral set comprises three flexible timer/counters with compare modes and PWM, two USARTs, a byte-oriented Two-Wire serial interface (TWI/I2C), an SPI serial port, an 8-channel 10-bit ADC, a real-time counter (RTC), and 32 general-purpose I/O lines. In-system programming (ISP) and JTAG debugging are supported through the dedicated pins.
Typical applications include industrial control and automation nodes, embedded sensing and data loggers, and consumer or IoT devices that need large program memory (128 KB Flash) and generous RAM (16 KB SRAM) without moving to a 32-bit platform.
When designing with this device, decouple VCC and AVCC separately with 0.1 uF ceramic capacitors close to the pins, and plan Flash self-programming (Read-While-Write) if bootloaders are used.
This page synthesizes distributor listings, drop-in family alternatives, pinout guidance, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATMEGA1284P-MUR β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA1284-MUR
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA1284P-MU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA1284-MU
β Drop-Inπ Reference alternative (not in catalog)
ATMEGA644PA-MUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA324PA-MUR
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA1284P-MUR Maximum Ratings & Electrical Characteristics
| Core | AVR 8-bit RISC |
| Max Clock Frequency | 20 MHz |
| Flash Program Memory | 128 KB (64K x 16), In-System Programmable |
| SRAM | 16 KB |
| EEPROM | 4 KB |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Throughput | Up to 20 MIPS at 20 MHz |
| General Purpose I/O Lines | 32 |
| USARTs | 2 |
| Timer/Counters | 3 (with compare modes and PWM) |
| ADC | 8-channel, 10-bit |
| Serial Interfaces | TWI (I2C, byte-oriented), SPI, 2x USART |
| Real Time Counter | Yes (RTC) |
| Working Registers | 32 x 8 general purpose |
| Instructions | 131 instructions, most single-cycle |
| Multiplier | On-chip 2-cycle hardware multiplier |
| Package | 44-VQFN (7x7 mm), exposed pad |
| Mounting Type | Surface Mount |
| Debug / Programming | ISP (In-Circuit Serial Programming), JTAG |
| Life Cycle Stage | Active |
ATMEGA1284P-MUR 44-vqfn (7x7 mm), exposed pad Pin Configuration Guide
Pin configuration for ATMEGA1284P-MUR (44-vqfn (7x7 mm), exposed pad package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for ATMEGA1284P-MUR.
Refer to the datasheet for full pin configuration.
Typical Applications
ATMEGA1284P-MUR is suitable for 6 applications: Industrial Control and Automation, Battery-Powered Data Loggers and Sensing Nodes, Embedded Communication Hubs, Consumer Appliances and Displays, Hobby, Maker, and Prototyping Platforms, Motor Control and PWM Actuation.
Industrial Control and Automation
The ATMEGA1284P-MUR fits industrial control nodes that need substantial program memory for protocol handling and multiple serial links. Its two USARTs can drive an RS-485 fieldbus and a debug/console port simultaneously, while the byte-oriented TWI interface and SPI port connect sensors, EEPROMs, and displays. The 128 KB Flash accommodates larger control state machines and field-updatable bootloaders with Read-While-Write, and the 16 KB SRAM buffers process data without external memory. Operating from a 5 V industrial rail with the 2.7 V to 5.5 V supply range and a 10-bit ADC for analog feedback, the device consolidates sensing, control, and communication on one chip. In-system programming via the JTAG/ICSP interface enables on-board firmware updates during production and servicing.
Recommended
Battery-Powered Data Loggers and Sensing Nodes
As a picoPower variant, the ATMEGA1284P-MUR suits battery-powered logging and sensing nodes where sleep-mode current dominates lifetime. The real-time counter allows timekeeping while the core sleeps, waking on timer or external interrupt to sample the 8-channel 10-bit ADC and return to sleep. The 4 KB EEPROM stores calibration and log metadata through power cycles, and 16 KB SRAM buffers sampled data between flash-write sessions, minimizing power-hungry program memory writes. The 2.7 V to 5.5 V supply range supports both 3 V lithium coin cells (via LDO) and 3.7 V lithium-ion packs directly. Designers trade peak clock (20 MHz) against duty cycle: running at 1-2 MHz from a divided clock dramatically reduces active current in duty-cycled acquisition loops.
Recommended
Embedded Communication Hubs
With two independent USARTs, an SPI port, and a TWI (I2C) master/slave interface, the ATMEGA1284P-MUR consolidates multi-protocol communication in one 5 V-tolerant 8-bit MCU. A typical hub bridges a slow sensor TWI bus to a faster SPI peripheral bank and forwards aggregated data over one USART while the second serves configuration or a secondary modem. The 16 KB SRAM is the standout here - it is the largest SRAM in the ATmega 8-bit family and allows ring buffers, packet reassembly, and protocol stacks (Modbus, simple TCP gateways) without external RAM. The 128 KB Flash holds both the application and a field-updatable bootloader, and Read-While-Write lets EEPROM/log writes proceed during communication.
Recommended
Consumer Appliances and Displays
Consumer products with LCD segments, buttons, and motor or relay outputs benefit from the ATMEGA1284P-MUR's balance of memory, PWM, and 5 V operation. Three timer/counters with compare modes generate PWM for backlight dimming, buzzer tones, or small motor speed control, while the 10-bit ADC reads temperature sensors, keypads, or battery voltage. The 128 KB Flash is generous for localized multi-language UI strings and rich menu graphics logic, and the picoPower design keeps standby consumption low for always-on appliances. The 44-pin VQFN (7x7 mm) exposed-pad package offers a compact, thermally robust footprint for automated assembly, and the device's full static operation lets clock frequency be scaled to the responsiveness the UI actually requires, saving power.
Recommended
Hobby, Maker, and Prototyping Platforms
The ATmega1284P is a popular upgrade path in maker communities precisely because it keeps the AVR instruction set and Arduino-style toolchain compatibility while doubling Flash and multiplying SRAM versus ATmega328-class boards. The ATMEGA1284P-MUR in VQFN suits semi-professional prototype builds with automated or reflow assembly; hobbyists using DIP sockets typically select the PDIP ATMEGA1284P-PU instead, which is not footprint-compatible but runs the same core. ISP programming via the SPI pins plus a bootloader means no external programmer is needed in the field, and JTAG enables serious debugging sessions. Community support includes existing core definitions, bootloader images, and board files, which reduces bring-up time substantially versus a new-architecture migration.
Recommended
Motor Control and PWM Actuation
The ATMEGA1284P-MUR's three timer/counters with compare modes and PWM outputs provide multiple independent PWM channels for brushed DC motor speed control, servo actuation, and LED intensity control. The 8-channel 10-bit ADC closes the loop by reading position potentiometers, current-sense resistors (with external shunt amplification), and temperature sensors, while the 20 MHz core computes PID updates fast enough for most low-cost motion applications - the on-chip 2-cycle hardware multiplier accelerates fixed-point PID arithmetic. Two USARTs allow one channel for a host command link and another for a motor-driver serial interface. The 5 V supply range and robust AVR I/O simplify direct interfacing with common H-bridge enable pins and optocoupled inputs.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA1284P-MUR β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA1284-MUR | ATMEGA1284P-MU | ATMEGA1284-MU | ATMEGA644PA-MUR |
|---|---|---|---|---|---|
| Package | 44-VQFN (7x7 mm) EP | 44-VQFN (7x7 mm) EP - same | 44-VQFN (7x7 mm) EP - same | 44-VQFN (7x7 mm) EP - same | 44-VQFN (7x7 mm) EP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 128 KB | 128 KB | 128 KB | 128 KB | 64 KB |
| SRAM | 16 KB | 16 KB | 16 KB | 16 KB | 8 KB |
| EEPROM | 4 KB | 4 KB | 4 KB | 4 KB | 2 KB |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| picoPower (Low Power) | Yes (P variant) | No (standard) | Yes (P variant) | No (standard) | Yes (PA variant) |
| Supply Voltage | 2.7 V to 5.5 V | 2.5 V to 5.5 V | 2.7 V to 5.5 V | 2.5 V to 5.5 V | 1.8 V to 5.5 V |
| Packing Format | Tape & Reel | Tape & Reel | Tray | Tray | Tape & Reel |
Key Differentiators
- picoPower sleep-mode optimization (vs ATMEGA1284-MUR)
- Largest SRAM in the ATmega 8-bit family (vs ATMEGA644PA-MUR)
- Tape & Reel for automated production (vs ATMEGA1284P-MU)
Design Notes
Decouple VCC and AVCC separately with 0.1 uF ceramic capacitors placed as close to each pin as possible, and tie the exposed pad of the 44-VQFN to a solid ground plane for both thermal relief and signal return. Keep the AREF pin filtered with a low-ESR capacitor when the ADC is used, and route analog traces away from the SPI/USART lines. The exposed pad is electrically significant on many VQFN ATmega parts - verify the datasheet land-pattern recommendation before finalizing the footprint.
The maximum 20 MHz rating applies across the full 2.7 V to 5.5 V supply range only within the datasheet's safe-operating curves; when running from 2.7 V, consult the frequency-vs-voltage curves before selecting the crystal. Also note that bootloader designs relying on Read-While-Write must reserve the correct boot-loader Flash section fuse settings - incorrect BOOTSZ/BOOTRST fuses are the most common cause of bricked field updates on ATmega1284-class parts.
The P (picoPower) variant distinguishes itself mainly in idle and sleep modes; to realize the benefit, actually enter sleep between tasks and use the RTC or pin-change interrupts to wake. Estimated: waking at 10 Hz for 1 ms of processing at 20 MHz gives a ~2 percent duty cycle, which typically dominates battery lifetime in sensing nodes. Avoid leaving unused GPIOs floating - configure them as outputs low or inputs with internal pull-ups per Microchip low-power application guidance.
Keep crystal/oscillator traces under ~10 mm with guard ground for reliable 20 MHz startup, and load the crystal with the capacitance the crystal manufacturer specifies (typically two 12-22 pF caps for common ATmega crystals). When using JTAG, remember that JTAG pins are shared with PORTC I/O; disabling JTAG via the JTAGEN fuse frees four GPIOs in production builds where debug access is not required.
Compliance Information
Compliance data was not included in the retrieved web data. Verify against the official Microchip environmental/compliance documentation for ATmega1284P before regulatory submission.
