5 and 6 Channel Capacitive Touch Sensor
Datasheet
3.3
SMBus Protocols
The CAP1006 is SMBus 2.0 compatible and supports Send Byte, Read Byte, Block Read, Receive
Byte as valid protocols as shown below. The CAP1006 also supports the I2C block read and block
write protocols. Finally, it will respond to the Alert Response Address protocol but is not in full
compliance.
All of the below protocols use the convention in Table 3.1.
Table 3.1 Protocol Format
DATA SENT
TO DEVICE
DATA SENT TO
THE HOST
Data sent
Data sent
3.3.1
SMBus Write Byte
The Write Byte is used to write one byte of data to a specific register as shown in Table 3.2.
Table 3.2 Write Byte Protocol
SLAVE
ADDRESS
REGISTER
ADDRESS
REGISTER
DATA
START
1 ->0
WR
ACK
ACK
ACK
STOP
0101_000
0
0
XXh
0
XXh
0
0 -> 1
3.3.2
Block Write
The Block Write is used to write multiple data bytes to a group of contiguous registers as shown in
Table 3.3. It is an extension of the Write Byte Protocol.
APPLICATION NOTE: When using the Block Write protocol, the internal address pointer will be automatically
incremented after every data byte is received. It will wrap from FFh to 00h.
Table 3.3 Block Write Protocol
SLAVE
ADDRESS
REGISTER
ADDRESS
REGISTER
DATA
START
WR
ACK
ACK
ACK
1 ->0
0101_000
0
0
XXh
0
XXh
0
REGISTER
DATA
REGISTER
DATA
REGISTER
DATA
ACK
ACK
. . .
ACK
STOP
XXh
0
XXh
0
. . .
XXh
0
0 -> 1
SMSC CAP1005 / CAP1006
Revision 1.1 (08-05-09)
DATA1S5HEET
SMSC [ SMSC CORPORATION ]
