BU7839GVW_10 Datasheet, PDF (9/16 Pages) Rohm – Digital Input Class-D Headphone Amplifier

BU7839GVW
Technical Note
・Acknowledge
After START condition is generated, data is transmitted at 8 bits once. After 8 bit transmission, the transmitter opens SDA,
and the receiver returns the acknowledge signal with SDA taken as L.
SDA output
by transmitter
SDA output
by receiver
Non-acknowledge
acknowledge
SCL
S
1
2
STARTCONDITION
8
9
Clock ulse
for acknowledge
・Write protocol
Write protocol is shown below. Register address is transmitted by 1 byte after device address and write command have
been transmitted. Third byte writes the data, which is written in by second byte, into internal register, and for fourth byte
and subsequent bytes, the register address is incremented automatically. But, the register address becomes 00h by the
transmission of 1 byte after the register address has become the final address (6Ch). The address is incremented after the
transmission is over.
S 0 1 1 0 0 1 1 0 A A7 A6 A5 A4 A3 A2 A1 A0 A D7 D6 D5 D4 D3 D2 D1 D0 A
Device address
R/W=0 (Write in)
Register address
data
Register address
increment
D7 D6 D5 D4 D3 D2 D1 D0 A P
data
Register address
increment
Transmitting set is on Master side
Transmitting set is on Slave side
A = Acknowledge
A = Non-acknowledge
S = START condition
P = STOP condition
Sr= Retransmission starting condition
・Readout protocol
Readout starts from 1 byte after device address and R/W bit have been written in. For the address after the readout
register is finally accessed and the subsequent addresses, the data of the addresses that have been incremented is read
out. As the readout of 1 byte after the address has become the final address, 00h is read out. The address is incremented
after the transmission is over.
S 0 1 1 0 0 1 1 0 A D7 D6 D5 D4 D3 D2 D1 D0 A
Device address
R/W=0 (Write in)
data
Register address
increment
D7 D6 D5 D4 D3 D2 D1 D0 A P
data
Register address
increment
Transmitting set is on Master side
Transmitting set is on Slave side
A = Acknowledge
A = Non-acknowledge
S = START condition
P = STOP condition
Sr= Retransmission starting condition
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2010.05 - Rev.A