AK9720 Datasheet, PDF (26/31 Pages) Asahi Kasei Microsystems – IR Sensor Module with I2C I/F

[AK9720]
SDA
S
T
A
R/W="1"
R
T
S ^Slave
Address
Data (n)
A
C
K
Data (n+1)
Data (n+2)
A
A
A
C
C
C
K
K
K
Fig.8. Current Address Read
S
T
O
P
Data (n+x)
P
A
C
K
2.2 Random Read
Data from an arbitrary address can be read out by a random read operation.
A random read requires the input of a dummy WRITE instruction before the input of a
slave address of a READ instruction (R/W bit=“1”). To execute a random read, first
generate a start condition, then input the slave address for a WRITE instruction (R/W
bit=“0”) and a read address, sequentially.
After the AK9720 generates an Acknowledge in response to this address input, generate
a start condition and the slave address for a READ instruction (R/W bit=“1”) again. The
AK9720 generates an Acknowledge in response to the input of this slave address. Next,
the AK9720 outputs the data at the specified address, then increments the internal address
counter by one.
When a Stop condition from the master device is generated instead of an Acknowledge
after the AK9720 outputs data, the Read operation stops.
SDA
S
T
A
R/W="0"
R
T
S
T
A
R/W="1"
R
T
S ^Slave
Address
Register
Address (n)
S ^Slave
Address
A
A
C
C
K
K
Data (n)
A
C
K
Data (n+1)
A
A
C
C
K
K
Fig.9. Random Read
S
T
O
P
Data (n+x)
P
A
C
K
Rev.02
AKM Confidential
- 26 -
2012/11