6 Channel Capacitive Touch Sensor with 2 LED Drivers
Datasheet
1. Register Read Address
updatedtoCurrent SPI Read
Address pointer.
2. Register Read Address
incremented = current address
pointer +1 – end result =
register address pointer doesn’t
change
1. Register Read Address
incremented = current address
pointer + 1
1. Register Read Address
updatedtoCurrent SPI Read
Address pointer
SPI_CS#
SPI_MISO
‘0’
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
‘0’
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
‘1’
XXh
Read Command – 7Fh
Subsequent Read Commands – 7Fh
Master SPDOUT
SPI_MOSI
Data at previously set register address = current
SPI_CLK
Data at previously set register address = current
address pointer (SPI)
Data at previously set register address = current
address pointer (SPI)
address pointer
Master Drives
Slave Drives
1. Output buffer transmitted=
data at previous address
pointer + 1 = current address
pointer
Register Data loaded into
Output buffer = data at current
address pointer + 1
1. Register data loaded into
output buffer = data at current
address pointer
1. Register data loaded into
output buffer = data at current
address pointer
1. SPI Read Address
Incremented = new current
address pointer
2. Register Read Address
Incremented = current address 1. Output buffer transmitted =
1. Output buffer transmitted =
data at current address pointer
+ 1
2. Flag set to increment SPI
Read Address at end of next 8
clocks
1. Output buffer transmitted =
data at current address pointer
+ 1
2. Flagset toincrement SPI
Read Address at end of next 8
clocks
pointer +1
data at previous register
address pointer + 1 = current
address pointer
Figure 3.6 SPI Read Command - Normal Mode - Full
3.6
Bi-Directional SPI Protocols
3.6.1
Reset Interface
Resets the Serial interface whenever two successive 7Ah codes are received. Regardless of the
current phase of the transaction - command or data, the receipt of the successive reset commands
resets the Serial communication interface only. All other functions are not affected by the reset
operation.
SPI_CS#
SPI_CLK
Master SPDOUT
SPI_MSIO
‘0’
‘1’
‘1’
‘1’
‘1’
‘0’
‘1’
‘0’
‘0’
‘1’
‘1’
‘1’
‘1’
‘0’
‘1’
‘0’
Reset - 7Ah
Reset - 7Ah
Figure 3.7 SPI Reset Interface Command - Bi-directional Mode
3.6.2
Set Address Pointer
Sets the address pointer to the register to be accessed by a read or write command. This command
overrides the auto-incrementing of the address pointer.
Revision 1.1 (08-05-09)
SMSC CAP1026
DATA2S4HEET
SMSC [ SMSC CORPORATION ]
