ATMEGA64A-AU Atmel, ATMEGA64A-AU Datasheet - Page 205
![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
21.4.2
21.4.3
8160C–AVR–07/09
START and STOP Conditions
Address Packet Format
The Master initiates and terminates a data transmission. The transmission is initiated when the
Master issues a START condition on the bus, and it is terminated when the Master issues a
STOP condition. Between a START and a STOP condition, the bus is considered busy, and no
other Master should try to seize control of the bus. A special case occurs when a new START
condition is issued between a START and STOP condition. This is referred to as a REPEATED
START condition, and is used when the Master wishes to initiate a new transfer without relin-
quishing control of the bus. After a REPEATED START, the bus is considered busy until the next
STOP. This is identical to the START behavior, and therefore START is used to describe both
START and REPEATED START for the remainder of this data sheet, unless otherwise noted.
As depicted below, START and STOP conditions are signalled by changing the level of the SDA
line when the SCL line is high.
Figure 21-4. START, REPEATED START, and STOP Conditions
All address packets transmitted on the TWI bus are nine bits long, consisting of seven address
bits, one READ/WRITE control bit and an acknowledge bit. If the READ/WRITE bit is set, a read
operation is to be performed, otherwise a write operation should be performed. When a slave
recognizes that it is being addressed, it should acknowledge by pulling SDA low in the ninth SCL
(ACK) cycle. If the addressed Slave is busy, or for some other reason can not service the Mas-
ter’s request, the SDA line should be left high in the ACK clock cycle. The Master can then
transmit a STOP condition, or a REPEATED START condition to initiate a new transmission. An
address packet consisting of a slave address and a READ or a WRITE bit is called SLA+R or
SLA+W, respectively.
The MSB of the address byte is transmitted first. Slave addresses can freely be allocated by the
designer, but the address 0000 000 is reserved for a general call.
When a general call is issued, all slaves should respond by pulling the SDA line low in the ACK
cycle. A general call is used when a Master wishes to transmit the same message to several
slaves in the system. When the general call address followed by a write bit is transmitted on the
bus, all slaves set up to acknowledge the general call will pull the SDA line low in the ack cycle.
The following data packets will then be received by all the slaves that acknowledged the general
call. Note that transmitting the general call address followed by a Read bit is meaningless, as
this would cause contention if several slaves started transmitting different data.
All addresses of the format 1111 xxx should be reserved for future purposes.
SDA
SCL
START
STOP START
REPEATED START
ATmega64A
STOP
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