ATMEGA2561V-8MI Atmel, ATMEGA2561V-8MI Datasheet - Page 246

• Manufacturer Part Number: ATMEGA2561V-8MI
• Description: IC AVR MCU 256K 8MHZ 64-QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA2561V-8MI

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 54
• Program Memory Size: 256KB (128K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-MLF®, 64-QFN
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

23.5
2549M–AVR–09/10
Overview of the TWI Module
Figure 23-8. Arbitration Between Two Masters
Note that arbitration is not allowed between:
•
•
•
It is the user software’s responsibility to ensure that these illegal arbitration conditions never
occur. This implies that in multi-master systems, all data transfers must use the same composi-
tion of SLA+R/W and data packets. In other words: All transmissions must contain the same
number of data packets, otherwise the result of the arbitration is undefined.
The TWI module is comprised of several submodules, as shown in
registers drawn in a thick line are accessible through the AVR data bus.
A REPEATED START condition and a data bit.
A STOP condition and a data bit.
A REPEATED START and a STOP condition.
Synchronized
SCL Line
SDA from
SDA from
Master A
Master B
SDA Line
START
ATmega640/1280/1281/2560/2561
Arbitration, SDA
Master A Loses
Figure 23-9 on page
A
SDA
247. All
246