SAM3SD8C Atmel Corporation, SAM3SD8C Datasheet - Page 604

• Manufacturer Part Number: SAM3SD8C
• Manufacturer: Atmel Corporation

29.6.2
29.6.3
29.7
29.7.1
604
604
Functional Description
SAM3S8/SD8
SAM3S8/SD8
Power Management
Interrupt
Transfer Format
The TWI interface may be clocked through the Power Management Controller (PMC), thus the
programmer must first configure the PMC to enable the TWI clock.
The TWI interface has an interrupt line connected to the Interrupt Controller. In order to handle
interrupts, the Interrupt Controller must be programmed before configuring the TWI.
Table 29-5.
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
29-4).
Each transfer begins with a START condition and terminates with a STOP condition (see
29-3).
Figure 29-3.
Figure 29-4. Transfer Format
• Enable the peripheral clock.
• 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.
Instance
TWI0
TWI1
TWD
TWCK
Peripheral IDs
START and STOP Conditions
Start
Address
TWCK
TWD
19
20
ID
R/W
Start
Ack
Data
Ack
Data
Stop
Ack
11090A–ATARM–10-Feb-12
11090A–ATARM–10-Feb-12
Stop
Figure
Figure