Atmel Evaluation Kit AT91SAM9X25-EK AT91SAM9X25-EK 数据表
产品代码
AT91SAM9X25-EK
747
SAM9X25 [DATASHEET]
11054E–ATARM–10-Mar-2014
38.7 Functional Description
38.7.1 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
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 38-3. START and STOP Conditions
Figure 38-4. Transfer Format
38.7.2 Modes of Operation
The TWI has different modes of operations:
Master transmitter mode
Master receiver mode
Multi-master transmitter mode
Multi-master receiver mode
Slave transmitter mode
Slave receiver mode
These modes are described in the following chapters.
TWD
TWCK
Start
Stop
TWD
TWCK
Start
Address
R/W
Ack
Data
Ack
Data
Ack
Stop