ATSAM3U-EK Atmel, ATSAM3U-EK Datasheet - Page 638

• Manufacturer Part Number: ATSAM3U-EK
• Description: KIT EVAL FOR AT91SAM3U CORTEX
• Manufacturer: Atmel
• Type: MCUr

Specifications of ATSAM3U-EK

• Contents: Board
• Processor To Be Evaluated: SAM3U
• Data Bus Width: 32 bit
• Interface Type: RS-232, USB
• Operating Supply Voltage: 3 V
• Silicon Manufacturer: Atmel
• Core Architecture: ARM
• Core Sub-architecture: Cortex - M3
• Silicon Core Number: SAM3U4E
• Silicon Family Name: SAM3U
• Kit Contents: Board CD Docs
• Rohs Compliant: Yes
• For Use With/related Products: AT91SAM3U
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 33-21. Programmer Sends Data While the Bus is Busy
Figure 33-22. Arbitration Cases
638
Data from a Master
TWI DATA transfer
TWI DATA transfer
Data from TWI
(DADR + W + START + Write THR)
(DADR + W + START + Write THR)
SAM3U Series
ARBLST
TWCK
A transfer is programmed
TWCK
TWD
TWD
A transfer is programmed
TWCK
TWD
Note:
The flowchart shown in
in Multi-master mode.
S
S
S
In the case where the arbitration is lost and TWI is addressed, TWI will not acknowledge even if it
is programmed in Slave mode as soon as ARBLST is set to 1. Then, the Master must repeat
SADR.
DATA sent by a master
1
1
1
Transfer is stopped
Bus is busy
0 0
0
0 0
1
STOP sent by the master
Transfer is kept
1 1
1 1
TWI stops sending data
Arbitration is lost
Figure 33-23 on page 639
(DADR + W + START + Write THR)
Transfer is programmed again
Data from the master
Bus is busy
Transfer is kept
Bus is free
Bus is considered as free
Transfer is initiated
P
P
Bus is free
gives an example of read and write operations
Bus is considered as free
Transfer is initiated
START sent by the TWI
S
S
S
1
1
1
0
0 0
0
DATA sent by the TWI
1
0
The master stops sending data
1 1
1 1
Arbitration is lost
6430D–ATARM–25-Mar-11
Data from the TWI