3 Channel Capacitive Touch Sensor with 3 LED Drivers
Datasheet
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
SMBus Read Byte
The Read Byte protocol is used to read one byte of data from the registers as shown in Table 3.3.
Table 3.3 Read Byte Protocol
START
SLAVE
ADDRESS
WR
ACK
REGISTER
ADDRESS
ACK
START
CLIENT
ADDRESS
RD
ACK
REGISTER
DATA
NACK
STOP
1->0
0101_000
0
0
XXh
0
1 ->0
0101_000
1
0
XXh
1
0 -> 1
3.3.3
SMBus Send Byte
The Send Byte protocol is used to set the internal address register pointer to the correct address
location. No data is transferred during the Send Byte protocol as shown in Table 3.4.
APPLICATION NOTE: The Send Byte protocol is not functional in Deep Sleep (i.e., DSLEEP bit is set).
Table 3.4 Send Byte Protocol
SLAVE
ADDRESS
REGISTER
ADDRESS
START
WR
ACK
ACK
STOP
1 -> 0
0101_000
0
0
XXh
0
0 -> 1
3.3.4
SMBus Receive Byte
The Receive Byte protocol is used to read data from a register when the internal register address
pointer is known to be at the right location (e.g., set via Send Byte). This is used for consecutive reads
of the same register as shown in Table 3.5.
APPLICATION NOTE: The Receive Byte protocol is not functional in Deep Sleep (i.e., DSLEEP bit is set).
Revision 1.32 (01-05-12)
SMSC CAP1133
DATA1S6HEET
SMSC [ SMSC CORPORATION ]
