Datasheet

8 Channel Capacitive Touch Sensor with 8 LED Drivers
Datasheet
Revision 1.32 (01-05-12) 42 SMSC CAP1188
DATASHEET
Bit 5 - STBY - Enables Standby.
‘0’ (default) - Sensor input scanning is active and LEDs are functional.
‘1’ - Capacitive touch sensor input scanning is limited to the sensor inputs set in the Standby
Channel register (see Section 5.20). The status registers will not be cleared until read. LEDs that
are linked to capacitive touch sensor inputs will remain linked and active. Sensor inputs that are
no longer sampled will flag a release and then remain in a non-touched state. LEDs that are
manually controlled will be unaffected.
Bit 4 - DSLEEP - Enables Deep Sleep by deactivating all functions. This bit will be cleared when the
WAKE pin is driven high. If the CAP1188 is configured to communicate using the BC-Link protocol,
this bit is ignored.
‘0’ (default) - Sensor input scanning is active and LEDs are functional.
‘1’ - All sensor input scanning is disabled. All LEDs are driven to their programmed non-actuated
state and no PWM operations will be done. The status registers are automatically cleared and the
INT bit is cleared.
Bit 0 - INT - Indicates that there is an interrupt. When this bit is set, it asserts the ALERT# pin. If a
channel detects a touch and its associated interrupt enable bit is not set to a logic ‘1’, no action is
taken.
This bit is cleared by writing a logic ‘0’ to it. When this bit is cleared, the ALERT# pin will be deasserted
and all status registers will be cleared if the condition has been removed. If the WAKE/SPI_MOSI pin
is asserted as a result of a touch detected while in Standby, it will likewise be deasserted when this
bit is cleared.
Note that the WAKE / SPI_MOSI pin is not driven when communicating via the 4-wire SPI protocol.
‘0’ - No interrupt pending.
‘1’ - A touch has been detected on one or more channels and the interrupt has been asserted.
5.2 Status Registers
All status bits are cleared when the device enters the Deep Sleep (DSLEEP = ‘1’ - see Section 5.1).
5.2.1 General Status - 02h
Bit 4 - LED - Indicates that one or more LEDs have finished their programmed activity. This bit is set
if any bit in the LED Status register is set.
Bit 3 - RESET - Indicates that the device has come out of reset. This bit is set when the device exits
a POR state or when the RESET pin has been deasserted and qualified via the RESET pin filter (see
Section 4.2). This bit will cause the INT bit to be set and is cleared when the INT bit is cleared.
Table 5.4 Status Registers
ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT
02h R General Status - - - LED RESET MULT MTP TOUCH 00h
03h R
Sensor Input
Status
CS8 CS7 CS6 CS5 CS4 CS3 CS2 CS1 00h
04h R LED Status
LED8_
DN
LED7_
DN
LED6_
DN
LED5_
DN
LED4_
DN
LED3_
DN
LED2_
DN
LED1_
DN
00h