ATmega640/1280/1281/2560/2561
The 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 one 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 ATmega640/1280/1281/2560/2561 provides the following features: 64K/128K/256K
bytes of In-System Programmable Flash with Read-While-Write capabilities, 4K bytes
EEPROM, 8K bytes SRAM, 54/86 general purpose I/O lines, 32 general purpose work-
ing registers, Real Time Counter (RTC), six flexible Timer/Counters with compare
modes and PWM, 4 USARTs, a byte oriented 2-wire Serial Interface, a 16-channel, 10-
bit ADC with optional differential input stage with programmable gain, 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 program-
ming 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 Oscilla-
tor, 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 main-
tain 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 min-
imize 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.
The device is manufactured using Atmel’s high-density nonvolatile 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. Soft-
ware 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-Program mable Flash on a monolithic ch ip, the Atmel
ATmega640/1280/1281/2560/2561 is a powerful microcontroller that provides a highly
flexible and cost effective solution to many embedded control applications.
The ATmega640/1280/1281/2560/2561 AVR 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.
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2549A–AVR–03/05
ATMEL [ ATMEL CORPORATION ]
