AK8858 Datasheet, PDF (63/96 Pages) Asahi Kasei Microsystems – PS/SD Multi Format Video Decoder

[8] Device control interface
The AK8858 is controlled via I2C bus control interface, as described below.
[AK8858]
[8.1] I2C bus SLAVE Address
Slave Address
SELA pin status MSB
LSB
Pulldown [Low] 1
0 0 0 1 0 0 R/W
Pullup [High]
1
0 0 0 1 0 1 R/W
[8.2] I2C control sequence
[8.2.1] Write sequence
After receiving a write-mode slave address first byte, the AK8858 receives the sub-address in the second byte
and data in the subsequent bytes. The write sequence may be single-byte or multi-byte.
(a) Single-byte write sequence
S Slave Address
wA
8-bit
1-bit
Sub Address
8-bit
A
Data
A
Stp
1-bit
8-bit
1-bit
(b) Multi-byte writes sequence (Sequential Write Operation)
S
Slave
Address
8-bit
wA
Sub
Address(n)
1-bit 8-bit
A
1-bit
Data(n)
8-bit
A
1-bit
Data
(n+1)
8-bit
A
1-bit
Data
‘’’’’’’
(n+m)
8-bit
A
1-bit
stp
[8.2.2] Read sequence
After receiving a read-mode slave address as first byte, the AK8858 sends data in the second and subsequent
bytes.
S
Slave
Address
w
A
Sub
Address(n)
A
rS
Slave
Address
R A Data1
A Data2
A Data3
A _{‘’’‘’}
8-bit
1 8-bit
1
8-bit
1 8-bit 1 8-bit 1 8-bit 1
S : Start Condition
rS : repeated Start Condition
A : Acknowledge (SDA Low )
!A : Not Acknowledge (SDA High)
stp : Stop Condition
R/W 1 : Read 0 : Write
: Received from master device (normally microprocessor)
: Output by slave device (AK8858)
’‘’’’’‘’’
‘’‘ Data n !A stp
8-bit 1
MS1230-E-00
- 63 -
2010/9