BU9409FV_12 Datasheet, PDF (7/58 Pages) Rohm – 32bit Audio DSP

BU9409FV
Technical Note
1.Command interface
I²C bus method is used in command interface with host CPU on BU9409FV.
In BU9409FV, not only writing but read-out is possible except for some registers.
Besides the slave address in BU9409FV, one byte select address can be Specified, written and readout.
The format of I²C bus slave mode is shown below.
MSB
LSB MSB
LSB MSB
S Slave Address
A Select Address
A Data
LSB
AP
S: Start condition
Slave Address:
Putting up the bit of read mode (H") or write mode (L") after slave address (7bit) set with ADDR,
the data of eight bits in total will be sent. (MSB first)
A: The acknowledge bit in each byte adds into the data when acknowledge is sent and received.
When data is correctly sent and received, "L" will be sent and received.
There was no acknowledge for "H".
Select Address: 1 byte select address is used in BU9409FV. (MSB first)
Data: Data-byte, data(MSB first)sent and received
P: Stop Condition
SDA
MSB 6
5
LSB
SCL
Start Condition
When SDA↓, SCL=”H”
Stop Condition
When SDA↑, SCL=”H”
1-1. Data writing
S Slave Address
ADDR=0
MSB
A6 A5 A4
1
0
0
ADDR=1
MSB
A6 A5 A4
1
0
0
A Select Address
A Data
AP
: From master to slave
: From slave to master
LSB
A3 A2 A1 A0 R/W
0
0
0
0
0
LSB
A3 A2 A1 A0 R/W
0
0
0
1
0
Setting of BU9409FV slave address
Terminal setting
Write-mode
ADDR
Slave-address
0
80h
1
82h
S Slave Address A Select Address
(example)
80h
20h
A Data
A Data
00h
00h
: From master to slave
A Data
AP
00h
: From slave to master
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2012.03 - Rev.A