W90P710_05 Datasheet, PDF (461/526 Pages) Winbond – 16/32-bit ARM microcontroller

W90P710
7.18.1 I²C Protocol
Normally, a standard communication consists of four parts:
1) START or Repeated START signal generation
2) Slave address transfer
3) Data transfer
4) STOP signal generation
SCL
SDA
S
or
Sr
1
2
A6
A5
MSB
A4 - A1
7
8
9
A0
R/W ACK
LSB
1
2
D7
D6
MSB
3-7
D5 - D1
8
9
D0
LSB
NACK
ACK
Fig. 7.18.1.1 Data transfer on the I²C-bus
P
P ^Sr
or
Sr
S SLAVE ADDRESS R/W A DATA A DATA A/A P
from master to slave
from slave to master
'0'(write)
data transfer
(n bytes + acknowledge)
A = acknowledge (SDA low)
A = not acknowledge (SDA high)
S = START condition
P = STOP condition
A master-transmitter addressing a slave receiver with a 7-bit address
The transfer direction is not changed
S SLAVE ADDRESS R/W A DATA A DATA A P
'1'(read)
data transfer
(n bytes + acknowledge)
A master reads a slave immediately after the first byte (address)
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Publication Release Date: January 17, 2005
Revision A.2