Kpp Pin Description; Input Pins; Output Pins; Kpp Programming Model - Motorola M-CORE MMC2001 Series Reference Manual

14.2 KPP Pin Description

Sixteen pins are dedicated to the KPP. Keypads of any configuration up to eight rows
and eight columns are supported through software configuration of the peripheral
pins. Any pins not used for the keypad are available for general-purpose input/output.
The registers are configured such that the pins can be treated as an I/O port up to 16
bits wide.

14.2.1 Input Pins

Any of the 16 pins associated with the KPP can be configured as inputs by writing
zeros to the appropriate bits in the KDDR. Additionally, the least significant eight bits
(ROW inputs) corresponding to KDDR[7:0] have internal pull-ups that are enabled
when the pin is used as an input.

14.2.2 Output Pins

Any of the 16 pins associated with the KPP can be configured as outputs by writing
the appropriate bits in the KDDR to one. Additionally, the pins representing the eight
most significant bits (KDDR[15:8]) can be designated as open drain outputs by writing
a one into the appropriate bits in KPCR. The pins representing the lower eight bits
(KDDR[7:0]) are always totem-pole style drive when configured as outputs.
KDDR[15:8]

14.3 KPP Programming Model

Address
10003000
10003002
10003004
10003006
10003008
to
10003FFF

14.3.1 Keypad Control Register (KPCR)

The keypad control register (KPCR) determines which of the eight possible column
strobes are to be open drain when configured as outputs and which of the eight row
sense lines are considered in generating an interrupt to the CPU.
MOTOROLA
14-2
Freescale Semiconductor, Inc.
Table 14-1 Keypad Port Column Modes
KPCR[15:8]
0 x
1 0
1 1
Table 14-2 Keypad Port Address Map
Use
Keypad Control Register (KPCR)
Keypad Status Register (KPSR)
Keypad Data Direction Register (KDDR)
Keypad Data Register (KPDR)
Reserved
KEYPAD PORT
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Pin Function
Input
Totem-Pole Output
Open-Drain Output
Access
Supervisor Only
Supervisor Only
Supervisor Only
Supervisor Only
Supervisor Only
REFERENCE MANUAL
MMC2001