Atmel Xplained Evaluation Board AT32UC3A3-XPLD AT32UC3A3-XPLD Datenbogen
Produktcode
AT32UC3A3-XPLD
478
32072H–AVR32–10/2012
AT32UC3A3
23.8
Functional Description
23.8.1
Transfer Format
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
be followed by an acknowledgement. The number of bytes per transfer is unlimited (see
).
Each transfer begins with a START condition and terminates with a STOP condition (see
).
• 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.
Figure 23-3. START and STOP Conditions
Figure 23-4. Transfer Format
23.8.2
Operation
The TWIM has two modes of operation:
• Master transmitter mode
• Master receiver mode
The master is the device which starts and stops a transfer and generates the TWCK clock.
These modes are described in the following chapters.
These modes are described in the following chapters.
TWD
TWCK
Start
Stop
TWD
TWCK
Start
Address
R/W
Ack
Data
Ack
Data
Ack
Stop