Signals - Intel PXA27 Series Design Manual

Keypad Interface
18.2

Signals

This section describes the keypad interface signals. See
Table 18-1. Interface Signals Summary
Name
KP_DKIN<7:0>
KP_MKIN<7:0>
KP_MKOUT<7:0>
II:18-2
Type
Direct Key Inputs – These are the input signals from the
direct keys and the rotary encoder sensors.
Pins KP_DKIN<7:4> are dedicated input pins for direct
keys 7 through 4.
Pins KP_DKIN<3:2> are used as input pins for direct keys
Input
3 and 2, or rotary-encoder sensor readings for rotary
encoder 1 if it is enabled.
Pins KP_DKIN<1:0> are used as input pins for direct keys
1 and 0 or rotary-encoder sensor readings for rotary
encoder 0 if it is enabled.
Matrix Key Returns – These are input signals from the
Input
matrix keypad and are the matrix keypad row readings.
Matrix Key Outputs – The keypad interface sends scan
signals to the columns of the matrix keypad to detect any
key(s) pressed.
In the Automatic Scan mode, the scan signals are sent
when the automatic scan (AS) bit of the keypad interface
Output
control (KPC) register is set, or if there is stable keypad
activity for one Key Debounce Interval and the automatic
scan on activity bit (ASACT) of the KPC is set.
In the Manual Scan mode, the scan signals are specified
in the KPC register.
Intel
Table 18-1 for summary of the signals.
Description
®
PXA27x Processor Family Design Guide