3
ATmega64A [DATASHEET]
8160D–AVR–02/2013
2.
Overview
The ATmega64A 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 ATmega64A achieves throughputs approaching 1 MIPS
per MHz, allowing the system designer to optimize power consumption versus processing speed.
2.1
Block Diagram
Figure 2-1.
Block Diagram
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 ATmega64A provides the following features: 64 Kbytes In-System Programmable Flash with Read-While-
Write capabilities, 2 Kbytes EEPROM, 4 Kbytes SRAM, 53 general purpose I/O lines, 32 general purpose working
registers, Real Time Counter (RTC), four flexible Timer/Counters with compare modes and PWM, two USARTs, a
byte oriented Two-wire Serial Interface, an 8-channel, 10-bit ADC with optional differential input stage with pro-
grammable gain, programmable Watchdog Timer with internal Oscillator, an SPI serial port, IEEE std. 1149.1
PROGRAM
COUNTER
INTERNAL
OSCILLATOR
WATCHDOG
TIMER
STACK
POINTER
PROGRAM
FLASH
MCU CONTROL
REGISTER
SRAM
GENERAL
PURPOSE
REGISTERS
INSTRUCTION
REGISTER
TIMER/
COUNTERS
INSTRUCTION
DECODER
DATA DIR.
REG. PORTB
DATA DIR.
REG. PORTE
DATA DIR.
REG. PORTA
DATA DIR.
REG. PORTD
DATA REGISTER
PORTB
DATA REGISTER
PORTE
DATA REGISTER
PORTA
DATA REGISTER
PORTD
TIMING AND
CONTROL
OSCILLATOR
INTERRUPT
UNIT
EEPROM
SPI
USART0
STATUS
REGISTER
Z
Y
X
ALU
PORTB DRIVERS
PORTE DRIVERS
PORTA DRIVERS
PORTF DRIVERS
PORTD DRIVERS
PORTC DRIVERS
PB0 - PB7
PE0 - PE7
PA0 - PA7
PF0 - PF7
RESET
VCC
GND
AREF
XTAL1
XTAL2
CONTROL
LINES
+
-
ANALOG
COMP
ARA
T
O
R
PC0 - PC7
8-BIT DATA BUS
AVCC
USART1
CALIB. OSC
DATA DIR.
REG. PORTC
DATA REGISTER
PORTC
ON-CHIP DEBUG
JTAG TAP
PROGRAMMING
LOGIC
PEN
BOUNDARY-
SCAN
DATA DIR.
REG. PORTF
DATA REGISTER
PORTF
ADC
PD0 - PD7
DATA DIR.
REG. PORTG
DATA REG.
PORTG
PORTG DRIVERS
PG0 - PG4
2-WIRE SERIAL
INTERFACE