218
2467S–AVR–07/09
ATmega128
enables the master to switch between slaves, Master Transmitter mode and Master Receiver
mode without losing control over the bus.
Figure 99.
Formats and States in the Master Receiver Mode
S
SLA
R
A
DATA
A
$08
$40
$50
SLA
R
$10
A
P
$48
A or A
$38
Other master
continues
$38
Other master
continues
W
A
$68
Other master
continues
$78
$B0
To corresponding
states in slave mode
MR
MT
Successfull
reception
from a slave
receiver
Next transfer
started with a
repeated start
condition
Not acknowledge
received after the
slave address
Arbitration lost in slave
address or data byte
Arbitration lost and
addressed as slave
DATA
A
n
From master to slave
From slave to master
Any number of data bytes
and their associated acknowledge bits
This number (contained in TWSR) corresponds
to a defined state of the Two-wire Serial Bus. The
prescaler bits are zero or masked to zero
P
DATA
A
$58
A
R
S