at91sam9g20-cu ATMEL Corporation, at91sam9g20-cu Datasheet - Page 420

• Manufacturer Part Number: at91sam9g20-cu
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

While no new data is written in the TWI_THR, the Serial Clock Line is tied low. When new data is
written in the TWI_THR, the SCL is released and the data is sent. To generate a STOP event,
the STOP command must be performed by writing in the STOP field of TWI_CR.
After a Master Write transfer, the Serial Clock line is stretched (tied low) while no new data is
written in the TWI_THR or until a STOP command is performed.
See
Figure
31-6,
Figure
31-7, and
Figure
31-8.
Figure 31-6. Master Write with One Data Byte
STOP Command sent (write in TWI_CR)
TWD
S
DADR
W
A
DATA
A
P
TXCOMP
TXRDY
Write THR (DATA)
Figure 31-7. Master Write with Multiple Data Bytes
STOP command performed
(by writing in the TWI_CR)
TWD
S
DADR
W
A
DATA n
A
DATA n+1
A
DATA n+2
A
P
TWCK
TXCOMP
TXRDY
Write THR (Data n)
Write THR (Data n+1)
Write THR (Data n+2)
Last data sent
AT91SAM9G20 Preliminary
420
6384B–ATARM–15-Dec-08