236
8025I–AVR–02/09
ATmega48P/88P/168P/328P
Figure 19-16. Formats and States in the Slave Receiver Mode
19.7.4
Slave Transmitter Mode
In the Slave Transmitter mode, a number of data bytes are transmitted to a Master Receiver
(see
). All the status codes mentioned in this section assume that the prescaler bits
are zero or are masked to zero.
Figure 19-17. Data Transfer in Slave Transmitter Mode
S
SLA
W
A
DATA
A
$60
$80
$88
A
$68
Reception of the own
slave address and one or
more data bytes. All are
acknowledged
Last data byte received
is not acknowledged
Arbitration lost as master
and addressed as slave
Reception of the general call
address and one or more data
bytes
Last data byte received is
not acknowledged
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 2-Wire Serial Bus. The
prescaler bits are zero or masked to zero
P or S
DATA
A
$80
$A0
P or S
A
A
DATA
A
$70
$90
$98
A
$78
P or S
DATA
A
$90
$A0
P or S
A
General Call
Arbitration lost as master and
addressed as slave by general call
DATA
A
Device 3
Device n
SDA
SCL
........
R1
R2
V
CC
Device 2
MASTER
RECEIVER
Device 1
SLAVE
TRANSMITTER