AK7755EN_16 Datasheet, PDF (82/109 Pages) Asahi Kasei Microsystems – DSP with Mono ADC Stereo CODEC + Mic/Lineout Amp

[AK7755]
2. Write Sequence
In the AK7755, when a “Write-Slave-address assignment” is received at the first byte, the write
command at the second byte and data at the third and succeeding bytes are received. At the data block,
address and write data are received in a single-byte unit each in accordance with a command code. The
number of write data bytes is fixed by the received command code.
S
T
A
R/W ="0"
R
T
SDA
Slave
S _Address
Command
Code
Data(n)
Data(n+1)
A
A
A
A
C
C
C
C
K
K
K
K
Figure 68. Write Sequence (I²C)
Data(n+x)
A
C
K
S
T
O
P
P
A
C
K
3. Read Sequence
In the AK7755, when a “write- slave-address assignment” is received at the first byte, the read command
at the second byte and the data at the third and succeeding bytes are received. At the data block, the
address is received in a single byte unit in accordance with a read command code. When the last address
byte (or command code if no address assignment is specified) is received and an acknowledgement is
transferred, the read command waits for the next restart condition. When a “read slave-address
assignment” is received at the first byte, data is transferred at the second and succeeding bytes. The
number of readable data bytes is fixed by the received read command.
After reading the last byte, assure that a “not acknowledged” signal is received. If this “not
acknowledged” signal is not received, the AK7755 continues to send data regardless whether data is
present or not, and since it does not release the BUS, the stop condition cannot be properly received.
S
T
A
R/W ="0"
R
T
SDA
Slave
S _Address
Command
code
A
C
K
Data(n)
A
C
K
R
E
S
T
A
R/W ="1"
R
T
Slave
S _Address
A
A
C
C
K
K
Data(n)
Data(n+1)
MA
MA
AC
AC
S
T
K
S
T
K
E
E
R
R
S
T
O
P
Data(n+x)
P
MA
MN
AC
AA
S
T
K
S
T
C
E
EK
R
R
Figure 69. Read Sequence (I²C)
014006643-E-00
- 82 -
2014/10