Description
The ATmega161 is a low-power CMOS 8-bit microcontroller based on the AVR RISC architecture. By executing powerful instructions in a single clock cycle, the ATmega161 achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed.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.

Features
• High-performance, Low-power AVR® 8-bit Microcontroller
• Advanced RISC Architecture
   – 130 Powerful Instructions - Most Single Clock Cycle Execution
   – 32 x 8 General Purpose Working Registers
   – Fully Static Operation
   – Up to 8 MIPS Throughput at 8 MHz
   – On-chip 2-cycle Multiplier
• Program and Data Memories
   – 16K Bytes of Nonvolatile In-System Programmable Flash
      Endurance: 1,000 Write/Erase Cycles
   – Optional Boot Code Memory with Independent Lock Bits
      Self-programming of Program and Data Memories
   – 512 Bytes Nonvolatile In-System Programmable EEPROM
      Endurance: 100,000 Write/Erase Cycles
   – 1K Bytes Internal SRAM
   – Programming Lock for Software Security
• Peripheral Features
   – Two 8-bit Timer/Counters with Separate Prescaler and PWM
   – Expanded 16-bit Timer/Counter System with Separate Prescaler, Compare,
      Capture Modes and Dual 8-, 9- or 10-bit PWM
   – Dual Programmable Serial UARTs
   – Master/Slave SPI Serial Interface
   – Real Time Counter with Separate Oscillator
   – Programmable Watchdog Timer with Separate On-chip Oscillator
   – On-chip Analog Comparator
• Special Microcontroller Features
   – Power-on Reset and Programmable Brown-out Detection
   – External and Internal Interrupt Sources
   – Three Sleep Modes: Idle, Power Save and Power-down
• I/O and Packages
   – 35 Programmable I/O Lines
   – 40-pin PDIP, 44-pin PLCC and TQFP
• Operating Voltages
   – 2.7V - 5.5V (ATmega161L), 4.0V - 5.5V (ATmega161)
• Speed Grades
   – 0 - 4 MHz (ATmega161L), 0 - 8 MHz (ATmega161)
• Commercial and Industrial Temperature Ranges