attiny261a-xu ATMEL Corporation, attiny261a-xu Datasheet - Page 4

• Manufacturer Part Number: attiny261a-xu
• Description: 8-bit Avr Microcontroller With 2/4/8k Bytes In-system Programmable Flash
• Manufacturer: ATMEL Corporation

2. Overview
2.1
4
Block Diagram
ATtiny261A/461A/861A
ATtiny261A/461A/861A are low-power CMOS 8-bit microcontrollers based on the AVR
enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the
devices achieve throughputs approaching 1 MIPS per MHz allowing the system designer to opti-
mize power consumption versus processing speed.
Figure 2-1.
The AVR core combines a rich instruction set with 32 general purpose working registers. All 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 con-
ventional CISC microcontrollers.
Block Diagram
Timer/Counter0
Generation
PORT B (8)
Watchdog
Watchdog
Oscillator
Oscillator
Circuits /
EEPROM
Timer
Clock
PB[0..7]
USI
Timer/Counter1
POR / BOD &
Supervision
Analog Comp.
PORT A (8)
Power
RESET
Flash
PA[0..7]
3
CPU
debugWIRE
A/D Conv.
PROGRAM
Bandgap
SRAM
Internal
LOGIC
11
RESET
XTAL[1..2]
AVCC
AGND
AREF
8197B–AVR–01/10