5 and 6 Channel Capacitive Touch Sensor
Datasheet
3.3.3
SMBus Read Byte
The Read Byte protocol is used to read one byte of data from the registers as shown in Table 3.4.
Table 3.4 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
3.3.4
Block Read
The Block Read is used to read multiple data bytes from a group of contiguous registers as shown in
Table 3.5. It is an extension of the Read Byte Protocol.
APPLICATION NOTE: When using the Block Read protocol, the internal address pointer will be automatically
incremented after every data byte is received. It will wrap from FFh to 00h.
Table 3.5 Block Read Protocol
START
SLAVE
ADDRESS
WR
ACK
REGISTER
ADDRESS
ACK
START
SLAVE
ADDRESS
RD
ACK
REGISTER
DATA
1->0
0101_000
0
0
XXh
0
1 ->0
0101_000
1
0
XXh
ACK
REGISTER
DATA
ACK
REGISTER
DATA
ACK
REGISTER
DATA
ACK
. . .
REGISTER
DATA
NACK
STOP
0
XXh
0
XXh
0
XXh
0
. . .
XXh
1
0 -> 1
3.3.5
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 3.6.
Table 3.6 Send Byte Protocol
SLAVE
ADDRESS
REGISTER
ADDRESS
START
1 -> 0
WR
ACK
ACK
STOP
0101_000
0
0
XXh
0
0 -> 1
3.3.6
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 3.7.
Table 3.7 Receive Byte Protocol
SLAVE
START
ADDRESS
RD
ACK
REGISTER DATA
NACK
STOP
1 -> 0
0101_000
1
0
XXh
1
0 -> 1
Revision 1.1 (08-05-09)
SMSC CAP1005 / CAP1006
DATA1S6HEET
SMSC [ SMSC CORPORATION ]
