AT32UC3A4256 Atmel Corporation, AT32UC3A4256 Datasheet - Page 477

• Manufacturer Part Number: AT32UC3A4256
• Manufacturer: Atmel Corporation

Specifications of AT32UC3A4256

• Flash (kbytes): 256 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 66 MHz
• Cpu: 32-bit AVR
• Hardware Qtouch Acquisition: No
• Usb Transceiver: 1
• Usb Speed: Hi-Speed
• Usb Interface: Device + OTG
• Spi: 6
• Twi (i2c): 2
• Uart: 4
• Ssc: 1
• Sd / Emmc: 2
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 128
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 3.0 to 3.6
• Operating Voltage (vcc): 3.0 to 3.6
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 6
• Output Compare Channels: 6
• Input Capture Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

23.8
23.8.1
23.8.2
32072G–11/2011
Functional Description
Transfer Format
Operation
The data put on the TWD line must be 8 bits long. Data is transferred MSB first; each byte must
be followed by an acknowledgement. The number of bytes per transfer is unlimited (see
23-4).
Each transfer begins with a START condition and terminates with a STOP condition (see
23-4).
Figure 23-3.
Figure 23-4. Transfer Format
The TWIM has two modes of operation:
The master is the device which starts and stops a transfer and generates the TWCK clock.
These modes are described in the following chapters.
• A high-to-low transition on the TWD line while TWCK is high defines the START condition.
• A low-to-high transition on the TWD line while TWCK is high defines a STOP condition.
• Master transmitter mode
• Master receiver mode
TWD
TWCK
START and STOP Conditions
Start
Address
TWCK
TWD
R/W
Start
Ack
Data
Ack
Data
Stop
Ack
Stop
Figure
Figure
477