ATMEGA64A-AU Atmel, ATMEGA64A-AU Datasheet - Page 15
![MCU AVR 64K ISP FLASH 64-TQFP](/photos/12/13/121332/313-64-tqfp_sml.jpg)
ATMEGA64A-AU
Manufacturer Part Number
ATMEGA64A-AU
Description
MCU AVR 64K ISP FLASH 64-TQFP
Manufacturer
Atmel
Series
AVR® ATmegar
Datasheets
1.ATMEGA64A-MUR.pdf
(21 pages)
2.ATMEGA64A-AU.pdf
(392 pages)
3.ATMEGA64A-AU.pdf
(3 pages)
Specifications of ATMEGA64A-AU
Core Processor
AVR
Core Size
8-Bit
Speed
16MHz
Connectivity
I²C, SPI, UART/USART
Peripherals
Brown-out Detect/Reset, POR, PWM, WDT
Number Of I /o
53
Program Memory Size
64KB (32K x 16)
Program Memory Type
FLASH
Eeprom Size
2K x 8
Ram Size
4K x 8
Voltage - Supply (vcc/vdd)
2.7 V ~ 5.5 V
Data Converters
A/D 8x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
64-TQFP, 64-VQFP
Package
64TQFP
Device Core
AVR
Family Name
ATmega
Maximum Speed
16 MHz
Operating Supply Voltage
3.3|5 V
Data Bus Width
8 Bit
Number Of Programmable I/os
53
Interface Type
SPI/USART
On-chip Adc
8-chx10-bit
Number Of Timers
4
Processor Series
ATMEGA64x
Core
AVR8
Data Ram Size
4 KB
Maximum Clock Frequency
16 MHz
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
3rd Party Development Tools
EWAVR, EWAVR-BL
Development Tools By Supplier
ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
Minimum Operating Temperature
- 40 C
Cpu Family
ATmega
Device Core Size
8b
Frequency (max)
16MHz
Total Internal Ram Size
4KB
# I/os (max)
53
Number Of Timers - General Purpose
4
Operating Supply Voltage (typ)
3.3/5V
Operating Supply Voltage (max)
5.5V
Operating Supply Voltage (min)
2.7V
Instruction Set Architecture
RISC
Operating Temp Range
-40C to 85C
Operating Temperature Classification
Industrial
Mounting
Surface Mount
Pin Count
64
Package Type
TQFP
For Use With
770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAG
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
ATMEGA64A-AU
Manufacturer:
ATMEL
Quantity:
4 500
Company:
Part Number:
ATMEGA64A-AU
Manufacturer:
Atmel
Quantity:
900
Company:
Part Number:
ATMEGA64A-AU
Manufacturer:
ATMEL85
Quantity:
900
Part Number:
ATMEGA64A-AU
Manufacturer:
AT
Quantity:
20 000
8160C–AVR–07/09
BOOTRST Fuse, see
281.
When an interrupt occurs, the Global Interrupt Enable I-bit is cleared and all interrupts are dis-
abled. The user software can write logic one to the I-bit to enable nested interrupts. All enabled
interrupts can then interrupt the current interrupt routine. The I-bit is automatically set when a
Return from Interrupt instruction – RETI – is executed.
There are basically two types of interrupts. The first type is triggered by an event that sets the
interrupt flag. For these interrupts, the Program Counter is vectored to the actual Interrupt Vector
in order to execute the interrupt handling routine, and hardware clears the corresponding inter-
rupt flag. Interrupt flags can also be cleared by writing a logic one to the flag bit position(s) to be
cleared. If an interrupt condition occurs while the corresponding interrupt enable bit is cleared,
the interrupt flag will be set and remembered until the interrupt is enabled, or the flag is cleared
by software. Similarly, if one or more interrupt conditions occur while the Global Interrupt Enable
bit is cleared, the corresponding interrupt flag(s) will be set and remembered until the Global
Interrupt Enable bit is set, and will then be executed by order of priority.
The second type of interrupts will trigger as long as the interrupt condition is present. These
interrupts do not necessarily have interrupt flags. If the interrupt condition disappears before the
interrupt is enabled, the interrupt will not be triggered.
When the AVR exits from an interrupt, it will always return to the main program and execute one
more instruction before any pending interrupt is served.
Note that the Status Register is not automatically stored when entering an interrupt routine, nor
restored when returning from an interrupt routine. This must be handled by software.
When using the CLI instruction to disable interrupts, the interrupts will be immediately disabled.
No interrupt will be executed after the CLI instruction, even if it occurs simultaneously with the
CLI instruction. The following example shows how this can be used to avoid interrupts during the
timed EEPROM write sequence.
Assembly Code Example
C Code Example
in r16, SREG
cli
sbi EECR, EEMWE
sbi EECR, EEWE
out SREG, r16
char cSREG;
cSREG = SREG;
/* disable interrupts during timed sequence */
_CLI();
EECR |= (1<<EEMWE); /* start EEPROM write */
EECR |= (1<<EEWE);
SREG = cSREG; /* restore SREG value (I-bit) */
; disable interrupts during timed sequence
/* store SREG value */
“Boot Loader Support – Read-While-Write Self-programming” on page
; store SREG value
; start EEPROM write
; restore SREG value (I-bit)
ATmega64A
15