BU9929FV Datasheet, PDF (9/12 Pages) Rohm – I2C BUS interface, general purpose I/O ports with condition watching function

Multimedia ICs
BU9929FV
3.Condition change detection result output mode
1) This IC becomes I²C master device, and the detection result is sent according to the following format;
2Byte Watching
St 0 0 0 1 0 0 0 W A
1Byte Watching
SLAVE ADDRESS +0
A WRITE DATA 1 A WRITE DATA 2
PION7 − PION0
PIO15 − PIO8
A Sp
St 0 0 0 1 0 0 0 W A SLAVE ADDRESS +0 A WRITE DATA 1 A Sp
PION7 − PION0
<DATA Keeping Operation>
In a case that there is a change in detection port during detection result transmission, then watching data is saved by the
end of detection output, and it will be proceeded further after the detection output is finished.
However, the output data in this case will be “AND” output of every bits of the watching data.
Watching Ports
Output for I²C BUS
FE
FC
F0
In the case of Arbitration;
Output is delayed
FE
FC
F8
AND Output of every bits of
the watching data
F0
2) DS pin Description
By DS pin, valid/invalid of condition detection of the default condition (from RESET release to reception of the first I²C
command) can be set.
<DS pic valid range>
In the range from RESET release to the first set of condition detection mode by I²C command, the set of this pin will be
valid. After the set of condition detection mode by I²C command, this pin will be invalid, and the set by I²C commanded
will be reflected.
<Pin setting>
DS pin= “H” : Input bit condition detection mode is valid.
But, 1 byte detection mode (only PION7-PION0 will be in condition detection)
DS pin=“L” : Input bit condition detection mode is invalid.
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