2490GAVR03/04
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 + Peripheral Control Registers
Fully Static Operation
Up to 16 MIPS Throughput at 16 MHz
On-chip 2-cycle Multiplier
Non-volatile Program and Data Memories
64K Bytes of In-System Reprogrammable Flash
Endurance: 10,000 Write/Erase Cycles
Optional Boot Code Section with Independent Lock Bits
In-System Programming by On-chip Boot Program
True Read-While-Write Operation
2K Bytes EEPROM
Endurance: 100,000 Write/Erase Cycles
4K Bytes Internal SRAM
Up to 64K Bytes Optional External Memory Space
Programming Lock for Software Security
SPI Interface for In-System Programming
JTAG (IEEE std. 1149.1 Compliant) Interface
Boundary-scan Capabilities According to the JTAG Standard
Extensive On-chip Debug Support
Programming of Flash, EEPROM, Fuses, and Lock Bits through the JTAG Interface
Peripheral Features
Two 8-bit Timer/Counters with Separate Prescalers and Compare Modes
Two Expanded 16-bit Timer/Counters with Separate Prescaler, Compare Mode, and
Capture Mode
Real Time Counter with Separate Oscillator
Two 8-bit PWM Channels
6 PWM Channels with Programmable Resolution from 1 to 16 Bits
8-channel, 10-bit ADC
8 Single-ended Channels
7 Differential Channels
2 Differential Channels with Programmable Gain (1x, 10x, 200x)
Byte-oriented Two-wire Serial Interface
Dual Programmable Serial USARTs
Master/Slave SPI Serial Interface
Programmable Watchdog Timer with On-chip Oscillator
On-chip Analog Comparator
Special Microcontroller Features
Power-on Reset and Programmable Brown-out Detection
Internal Calibrated RC Oscillator
External and Internal Interrupt Sources
Six Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down, Standby
and Extended Standby
Software Selectable Clock Frequency
ATmega103 Compatibility Mode Selected by a Fuse
Global Pull-up Disable
I/O and Packages
53 Programmable I/O Lines
64-lead TQFP and 64-pad MLF
Operating Voltages
2.7 - 5.5V for ATmega64L
4.5 - 5.5V for ATmega64
Speed Grades
0 - 8 MHz for ATmega64L
0 - 16 MHz for ATmega64
8-bit
Microcontroller
with 64K Bytes
In-System
Programmable
Flash
ATmega64
ATmega64L
Preliminary
3
ATmega64(L)
2490GAVR03/04
Overview
The ATmega64 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 ATmega64 achieves throughputs approaching 1 MIPS per MHz, allowing
the system designer to optimize power consumption versus processing speed.
Block Diagram
Figure 2. 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.
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
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
AGND
GND
AREF
XTAL1
XTAL2
CONTROL
LINES
+
-
ANALOG
COMP
ARA
TOR
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
4
ATmega64(L)
2490GAVR03/04
The ATmega64 provides the following features: 64K bytes of In-System Programmable
Flash with Read-While-Write capabilities, 2K bytes EEPROM, 4K bytes SRAM, 53 gen-
eral 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 ori-
ented Two-wire Serial Interface, an 8-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 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 asyn-
chronous 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 asynchro-
nous timer continue to run.
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 non-volatile 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-Programmable Flash on a monolithic chip, the Atmel ATmega64 is
a powerful microcontroller that provides a highly-flexible and cost-effective solution to
many embedded control applications.
The ATmega64 AVR is supported with a full suite of program and system development
tools including: C compilers, macro assemblers, program debugger/simulators, In-Cir-
cuit Emulators, and evaluation kits.
ATmega103 and
ATmega64 Compatibility
The ATmega64 is a highly complex microcontroller where the number of I/O locations
supersedes the 64 I/O location reserved in the AVR instruction set. To ensure backward
compatibility with the ATmega103, all I/O locations present in ATmega103 have the
same location in ATmega64. Most additional I/O locations are added in an Extended I/O
space starting from 0x60 to 0xFF (i.e., in the ATmega103 internal RAM space). These
location can be reached by using LD/LDS/LDD and ST/STS/STD instructions only, not
by using IN and OUT instructions. The relocation of the internal RAM space may still be
a problem for ATmega103 users. Also, the increased number of Interrupt Vectors might
be a problem if the code uses absolute addresses. To solve these problems, an
ATmega103 compatibility mode can be selected by programming the fuse M103C. In
this mode, none of the functions in the Extended I/O space are in use, so the internal
RAM is located as in ATmega103. Also, the extended Interrupt Vectors are removed.
The ATmega64 is 100% pin compatible with ATmega103, and can replace the
ATmega103 on current printed circuit boards. The application note "Replacing
ATmega103 by ATmega64" describes what the user should be aware of replacing the
ATmega103 by an ATmega64.
5
ATmega64(L)
2490GAVR03/04
ATmega103 Compatibility
Mode
By programming the M103C Fuse, the ATmega64 will be compatible with the
ATmega103 regards to RAM, I/O pins and Interrupt Vectors as described above. How-
ever, some new features in ATmega64 are not available in this compatibility mode,
these features are listed below:
One USART instead of two, asynchronous mode only. Only the eight least
significant bits of the Baud Rate Register is available.
One 16 bits Timer/Counter with two compare registers instead of two 16 bits
Timer/Counters with three compare registers.
Two-wire serial interface is not supported.
Port G serves alternate functions only (not a general I/O port).
Port F serves as digital input only in addition to analog input to the ADC.
Boot Loader capabilities is not supported.
It is not possible to adjust the frequency of the internal calibrated RC Oscillator.
The External Memory Interface can not release any Address pins for general I/O,
neither configure different wait states to different External Memory Address
sections.
Only EXTRF and PORF exist in the MCUCSR Register.
No timed sequence is required for Watchdog Timeout change.
Only low-level external interrupts can be used on four of the eight External Interrupt
sources.
Port C is output only.
USART has no FIFO buffer, so Data OverRun comes earlier.
The user must have set unused I/O bits to 0 in ATmega103 programs.
Pin Descriptions
VCC
Digital supply voltage.
GND
Ground.
Port A (PA7..PA0)
Port A is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each
bit). The Port A output buffers have symmetrical drive characteristics with both high sink
and source capability. As inputs, Port A pins that are externally pulled low will source
current if the pull-up resistors are activated. The Port A pins are tri-stated when a reset
condition becomes active, even if the clock is not running.
Port A also serves the functions of various special features of the ATmega64 as listed
on page 71.
Port B (PB7..PB0)
Port B is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each
bit). The Port B output buffers have symmetrical drive characteristics with both high sink
and source capability. As inputs, Port B pins that are externally pulled low will source
current if the pull-up resistors are activated. The Port B pins are tri-stated when a reset
condition becomes active, even if the clock is not running.
Port B also serves the functions of various special features of the ATmega64 as listed
on page 72.
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