BU9969KN_09 Datasheet, PDF (9/14 Pages) Rohm – Video bus interface

BU9969KN
Technical Note
●Serial Interface Format
The slave address of the device is E0h.
SDI
SCLK
S
START
1～7
ADDR
8
R/W
9
ACK
1～7
8
9
SUBADDRESS
ACK
Bus data transfer
1～7
8
DATA
9
ACK
P
STOP
Write
sequence ^S
1110_000
Slave
ADDR
0
W A(S)
(write)
Sub ADDR
A(S)
Data
A(S) ^{・・・}
1110_000 0
1110_000 1
Read
sequence
S
Slave
ADDR
W A(S) Sub ADDR A(S) S
Slave
ADDR
R A(S)
(write)
(read)
Data
Data
A(S) P
・・・
A(M)
Data
A(M) P
S = start bit
P = stop bit
Write / read sequence
A(S) = acknowledge by slave
A(M) = acknowledge by master
A(S) = no acknowledge by slave
A(M) = no acknowledge by master
●Serial Interface Timing
Fig.4. Serial Interface Format
SDI
t1df
SCLK
t1hSTA t1sr
t1s
t1sf
t1wh t1wl
t1s: DATA set-up time
t1wl: SCLK “L” pulse width
t1hSTA: Hold time START condition
t1sSTO: Set-up time for STOP condition
90%
10%
t1h
t1dr ^tBUF
90%
t1sSTA
10%
t1sSTO
t1h: DATA hold time
t1wh: SCLK “H” pulse width
t1sSTA: Set-up time for a repeated START condition
*Please change the SDA after SCLK is stabilized in Low except the condition "START" and "STOP".
Fig.5. Serial Interface Timing Diagram
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9/13
2009.05 - Rev.A