STMPE1801BJR Datasheet, PDF (45/60 Pages) STMicroelectronics – Xpander Logic 18-bit enhanced port expander with keypad controller

STMPE1801
Keypad controller
The KPC_LOCK bit is only used when a combination key is configured in the device. If there
is no combination key programmed, then this bit is not used. This command is used in
conjunction with the combination keys. After the device has entered the keypad lock state,
all subsequent key presses are ignored until the combinational key(s) are detected.
Thereafter, the device exits the lock state, sets the combinational key wakeup status in the
interrupt status register bit IS[4] and sends out the interrupt if it was enabled.
0: Writing 0 aborts the key lock
Writing a 0 to this bit cancels any earlier key lock execution command. If the device has
already entered the lock state, writing 0 exits the lock state.
This bit is readable by the Host and the read status is described as follows:
Reading [1]: KPC lock execution is not completed. It is either waiting for the key press to
stop to enter the lock state or it is already in the lock state.
Reading [0]: KPC is already not in lock state, and not waiting to enter lock state.
[0]SCAN:
1: to start scanning
0: to stop
Note:
All the key configurations and control must be completed before executing the scan
command. Any configuration and control change while scan is active is not supported.
Doc ID 17884 Rev 3
45/60