ATmega64 Atmel Corporation, ATmega64 Datasheet - Page 212

• Manufacturer Part Number: ATmega64
• Manufacturer: Atmel Corporation

Specifications of ATmega64

• Flash (kbytes): 64 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 53
• Ext Interrupts: 8
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 2
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 4
• Eeprom (bytes): 2048
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 4
• Output Compare Channels: 8
• Input Capture Channels: 2
• Pwm Channels: 7
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

Transmission
Modes
2490Q–AVR–06/10
The TWI can operate in one of four major modes. These are named Master Transmitter (MT),
Master Receiver (MR), Slave Transmitter (ST) and Slave Receiver (SR). Several of these
modes can be used in the same application. As an example, the TWI can use MT mode to write
data into a TWI EEPROM, MR mode to read the data back from the EEPROM. If other masters
are present in the system, some of these might transmit data to the TWI, and then SR mode
would be used. It is the application software that decides which modes are legal.
The following sections describe each of these modes. Possible status codes are described
along with figures detailing data transmission in each of the modes. These figures contain the
following abbreviations:
In
in the circles show the status code held in TWSR, with the prescaler bits masked to zero. At
these points, actions must be taken by the application to continue or complete the TWI transfer.
The TWI transfer is suspended until the TWINT flag is cleared by software.
When the TWINT flag is set, the status code in TWSR is used to determine the appropriate soft-
ware action. For each status code, the required software action and details of the following serial
transfer are given in
these tables.
S:
Rs:
R:
W:
A:
A:
Data:
P:
SLA:
Figure 97
to
START condition
REPEATED START condition
Read bit (high level at SDA)
Write bit (low level at SDA)
Acknowledge bit (low level at SDA)
Not acknowledge bit (high level at SDA)
8-bit data byte
STOP condition
Slave Address
Figure
Table 88
103, circles are used to indicate that the TWINT flag is set. The numbers
to
Table
91. Note that the prescaler bits are masked to zero in
ATmega64(L)
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