ATMEGA2560V-8AU Atmel, ATMEGA2560V-8AU Datasheet - Page 248

• Manufacturer Part Number: ATMEGA2560V-8AU
• Description: IC AVR MCU 256K 8MHZ 100TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA2560V-8AU

• 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: 86
• 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 16x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-TQFP, 100-VQFP
• Processor Series: ATMEGA256x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 8 KB
• Interface Type: 2-Wire, SPI, USART
• Maximum Clock Frequency: 8 MHz
• Number Of Programmable I/os: 86
• Number Of Timers: 6
• Operating Supply Voltage: 1.8 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 16 Channel
• A/d Inputs: 16-Channel, 10-Bit
• Cpu Speed: 8 MIPS
• Eeprom Memory: 4K Bytes
• Input Output: 86
• Interface: 2-Wire/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 100-pin TQFP
• Programmable Memory: 256K Bytes
• Timers: 2-8-bit, 4-16-bit
• Voltage, Range: 1.8-5.5 V
• Package: 100TQFP
• Device Core: AVR
• Family Name: ATmega
• Maximum Speed: 8 MHz
• For Use With: ATSTK600-TQFP100 - STK600 SOCKET/ADAPTER 100-TQFP770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAG770-1005 - ISP 4PORT FOR ATMEL AVR MCU JTAG770-1004 - ISP 4PORT FOR ATMEL AVR MCU SPIATAVRISP2 - PROGRAMMER AVR IN SYSTEMATSTK503 - STARTER KIT AVR EXP MODULE 100PATJTAGICE2 - AVR ON-CHIP D-BUG SYSTEM
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

23.5.3
23.5.4
23.5.5
2549M–AVR–09/10
Bus Interface Unit
Address Match Unit
Control Unit
The SCL frequency is generated according to the following equation:
•
•
Note:
This unit contains the Data and Address Shift Register (TWDR), a START/STOP Controller and
Arbitration detection hardware. The TWDR contains the address or data bytes to be transmitted,
or the address or data bytes received. In addition to the 8-bit TWDR, the Bus Interface Unit also
contains a register containing the (N)ACK bit to be transmitted or received. This (N)ACK Regis-
ter is not directly accessible by the application software. However, when receiving, it can be set
or cleared by manipulating the TWI Control Register (TWCR). When in Transmitter mode, the
value of the received (N)ACK bit can be determined by the value in the TWSR.
The START/STOP Controller is responsible for generation and detection of START, REPEATED
START, and STOP conditions. The START/STOP controller is able to detect START and STOP
conditions even when the AVR MCU is in one of the sleep modes, enabling the MCU to wake up
if addressed by a Master.
If the TWI has initiated a transmission as Master, the Arbitration Detection hardware continu-
ously monitors the transmission trying to determine if arbitration is in process. If the TWI has lost
an arbitration, the Control Unit is informed. Correct action can then be taken and appropriate
status codes generated.
The Address Match unit checks if received address bytes match the seven-bit address in the
TWI Address Register (TWAR). If the TWI General Call Recognition Enable (TWGCE) bit in the
TWAR is written to one, all incoming address bits will also be compared against the General Call
address. Upon an address match, the Control Unit is informed, allowing correct action to be
taken. The TWI may or may not acknowledge its address, depending on settings in the TWCR.
The Address Match unit is able to compare addresses even when the AVR MCU is in sleep
mode, enabling the MCU to wake up if addressed by a Master. If another interrupt (for example,
INT0) occurs during TWI Power-down address match and wakes up the CPU, the TWI aborts
operation and return to it’s idle state. If this cause any problems, ensure that TWI Address Match
is the only enabled interrupt when entering Power-down.
The Control unit monitors the TWI bus and generates responses corresponding to settings in the
TWI Control Register (TWCR). When an event requiring the attention of the application occurs
on the TWI bus, the TWI Interrupt Flag (TWINT) is asserted. In the next clock cycle, the TWI Sta-
tus Register (TWSR) is updated with a status code identifying the event. The TWSR only
contains relevant status information when the TWI Interrupt Flag is asserted. At all other times,
the TWSR contains a special status code indicating that no relevant status information is avail-
able. As long as the TWINT Flag is set, the SCL line is held low. This allows the application
software to complete its tasks before allowing the TWI transmission to continue.
TWBR = Value of the TWI Bit Rate Register.
TWPS = Value of the prescaler bits in the TWI Status Register.
Pull-up resistor values should be selected according to the SCL frequency and the capacitive bus
line load. See
“2-wire Serial Interface Characteristics” on page 372
SCL frequency
ATmega640/1280/1281/2560/2561
=
---------------------------------------------------------- -
16
CPU Clock frequency
+
2(TWBR) 4
⋅
TWPS
for value of pull-up resistor.
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