BD6039GU Datasheet, PDF (11/25 Pages) Rohm – Power Supply for CCD Camera Module

BD6039GU
Technical Note
●I²C BUS format
The writing/reading operation is based on the I2C slave standard.
◦Slave address
A7
A6
A5
A4
A3
A2
A1 R/W
0
0
0
1
0
0
1
1/0
◦Bit Transfer
SCL transfers 1-bit data during H. SCL cannot change signal of SDA during H at the time of bit transfer. If SDA changes
while SCL is H, START conditions or STOP conditions will occur and it will be interpreted as a control signal.
SDA
SCL
data line
Stable; data valid
change of
data
allowed
◦START and STOP condition
When SDA and SCL are H, data is not transferred on the I2C- bus. This condition indicates, if SDA changes from H to L
while SCL has been H, it will become START (S) conditions, and an access start, if SDA changes from L to H while SCL has
been H, it will become STOP (P) conditions and an access end.
SDA
SCL
S
START condition
P
STOP condition
◦Acknowledge
It transfers data 8 bits each after the occurrence of START condition. A transmitter opens SDA after transfer 8bits data, and
a receiver returns the acknowledge signal by setting SDA to L.
DATA OUTPUT
BY TRANSMITTER
DATA OUTPUT
BY RECEIVER
SCL
1
S
START condition
not acknowledge
acknowledge
2
8
9
clock pulse for
acknowledgement
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11/24
2010.03 - Rev.A