Datasheet

TCA8418
SCPS215B –SEPTEMBER 2009–REVISED MARCH 2010 www.ti.com
BIT NAME DESCRIPTION
GPI interrupt enable to host processor
0 = disabled
1 GPI_IEN
1 = enabled
Can be used to mask interrupts
Key events interrupt enable to host processor
0 KE_IEN
0 = disabled
1 = enabled Can be used to mask interrupts
Bit 7 in this register is used to determine the programming mode. If it is low, all data bytes are written to the
registers defined command byte. If bit 7 is high, the value of the command byte is automatically incremented
after the byte is written, and the next data byte is stored in the corresponding register. Registers are written in
the sequence shown in Table 5. Once the GPIO_PULL3 register (0×2E) is written to, the command byte returns
to 0 (Configuration register). Registers 0 and 2F are reserved and a command byte that references these
registers is not acknowledged by the TCA8418.
The keypad lock interrupt enable determines if the interrupt pin is asserted when the key lock interrupt (see
Interrupt Status Register) bit is set.
Interrupt Status Register, INT_STAT (Address 0×02)
BIT NAME DESCRIPTION
7 N/A Always 0
6 N/A Always 0
5 N/A Always 0
CTRL-ALT-DEL key sequence status. Requires writing a 1 to clear interrupts.
4 CAD_INT
0 = interrupt not detected
1 = interrupt detected
Overflow interrupt status. Requires writing a 1 to clear interrupts.
3 OVR_FLOW_INT
0 = interrupt not detected
1 = interrupt detected
Keypad lock interrupt status. This is the interrupt to the processor when the keypad lock
sequence is started. Requires writing a 1 to clear interrupts.
2 K_LCK_INT
0 = interrupt not detected
1 = interrupt detected
GPI interrupt status. Requires writing a 1 to clear interrupts.
0 = interrupt not detected
1 GPI_INT
1 = interrupt detected
Can be used to mask interrupts
Key events interrupt status. Requires writing a 1 to clear interrupts.
0 K_INT
0 = interrupt not detected
1 = interrupt detected
Key Lock and Event Counter Register, KEY_LCK_EC (Address 0×03)
BIT NAME DESCRIPTION
7 N/A Always 0
Key lock enable
6 K_LCK_EN
0 = disabled
1 = enabled
Keypad lock status
5 LCK2
0 = unlock (if LCK1 is 0 too)
1 = locked (if LCK1 is 1 too)
16 Submit Documentation Feedback Copyright © 2009–2010, Texas Instruments Incorporated
Product Folder Link(s): TCA8418