The Atmel® ATmega1284 is a low-power CMOS 8-bit microcontroller based on the AVR enhanced RISC
architecture. By executing powerful instructions in a single clock cycle, the ATmega1284 achieves
throughputs close to 1MIPS per MHz. This empowers system designer to optimize the device for power
consumption versus processing speed.
The Atmel AVR® core combines a rich instruction set with 32 general purpose working registers. All the
32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two independent registers
to be accessed in a single instruction executed in one clock cycle. The resulting architecture is more code
efficient while achieving throughputs up to ten times faster than conventional CISC microcontrollers.
The ATmega1284 provides the following features: 128Kbytes of In-System Programmable Flash with
Read-While-Write capabilities, 4Kbytes EEPROM, 16Kbytes SRAM, 32 general purpose I/O lines, 32
general purpose working registers, Real Time Counter (RTC), three flexible Timer/Counters with compare
modes and PWM, two serial programmable USARTs , one byte-oriented 2-wire Serial Interface (I2C), a 8-
channel 10-bit ADC with optional differential input stage with programmable gain, a programmable
Watchdog Timer with internal Oscillator, an SPI serial port, IEEE std. 1149.1 compliant JTAG test
interface, also used for accessing the On-chip Debug system and programming and six software
selectable power saving modes. The Idle mode stops the CPU while allowing the SRAM, Timer/Counters,
SPI port, and interrupt system to continue functioning. The Power-down mode saves the register contents
but freezes the Oscillator, disabling all other chip functions until the next interrupt or hardware reset. In
Power-save mode, the asynchronous timer continues to run, allowing the user to maintain a timer base
while the rest of the device is sleeping. The ADC Noise Reduction mode stops the CPU and all I/O
modules except asynchronous timer and ADC to minimize switching noise during ADC conversions. In
Standby mode, the crystal/resonator oscillator is running while the rest of the device is sleeping. This
allows very fast start-up combined with low power consumption. In Extended Standby mode, both the
main oscillator and the asynchronous timer continue to run.
Atmel offers the QTouch® library for embedding capacitive touch buttons, sliders and wheels functionality
into AVR microcontrollers. The patented charge-transfer signal acquisition offers robust sensing and
includes fully debounced reporting of touch keys and includes Adjacent Key Suppression® (AKS™)
technology for unambiguous detection of key events. The easy-to-use QTouch Suite toolchain allows you
to explore, develop and debug your own touch applications.
The device is manufactured using Atmel’s high density non-volatile memory technology. The On-chip ISP
Flash allows the program memory to be reprogrammed In-System through an SPI serial interface, by a
conventional nonvolatile memory programmer, or by an On-chip Boot program running on the AVR core.
The Boot program can use any interface to download the application program in the Application Flash
memory. Software in the Boot Flash section will continue to run while the Application Flash section is
updated, providing true Read-While-Write operation. By combining an 8-bit RISC CPU with In-System
Self-Programmable Flash on a monolithic chip, the Atmel ATmega1284 is a powerful microcontroller that
provides a highly flexible and cost effective solution to many embedded control applications.
The ATmega1284 is supported with a full suite of program and system development tools including: C
Compilers, Macro Assemblers, Program Debugger/Simulators, In-Circuit Emulators, and Evaluation kits.
Atmel ATmega1284 [DATASHEET]