Datasheet

8 Channel Capacitive Touch Sensor with 8 LED Drivers

Datasheet

Revision 1.32 (01-05-12) 20 SMSC CAP1188

DATASHEET

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 3.3.

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 3.4.

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 3.5.

APPLICATION NOTE: The Send Byte protocol is not functional in Deep Sleep (i.e., DSLEEP bit is set).

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 3.6.

APPLICATION NOTE: The Receive Byte protocol is not functional in Deep Sleep (i.e., DSLEEP bit is set).

Table 3.3 Write Byte Protocol

START

SLAVE

ADDRESS WR ACK

ADDRESS ACK

DATA ACK STOP

1 ->0 YYYY_YYY 0 0 XXh 0 XXh 0 0 -> 1

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 YYYY_YYY 0 0 XXh 0 1 ->0 YYYY_YYY 1 0 XXh 1 0 -> 1

Table 3.5 Send Byte Protocol

START

SLAVE

ADDRESS WR ACK

ADDRESS ACK STOP

1 -> 0 YYYY_YYY 0 0 XXh 0 0 -> 1

Table 3.6 Receive Byte Protocol

START

SLAVE

ADDRESS RD ACK REGISTER DATA NACK STOP

1 -> 0 YYYY_YYY 1 0 XXh 1 0 -> 1