Specifications

WM_PRJ_Q2501_PTS_002 - 001
March 2004
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3.3.5 Keyboard interface
This interface provides 10 connections:
 5 rows (ROW0 to ROW4),
 5 columns (COL0 to COL4).
The scanning is a digital one, and the debouncing is done in the WISMO
module. No discrete components like resistors or capacitors are needed.
The keyboard scanner is equipped with internal pull-down resistors for the
rows and pull-up resistors for the columns. Current only flows from the
column pins to the row pins. This allows a transistor to be used in place of the
switch for power-on functions.
Pin description
Signal Pin # I/O I/O type Description
ROW0 33 I/O CMOS / 1X Row scan
ROW1 35 I/O CMOS / 1X Row scan
ROW2 37 I/O CMOS / 1X Row scan
ROW3 39 I/O CMOS / 1X Row scan
ROW4 41 I/O CMOS / 1X Row scan
COL0 43 I/O CMOS / 1X Column scan
COL1 45 I/O CMOS / 1X Column scan
COL2 47 I/O CMOS / 1X Column scan
COL3 49 I/O CMOS / 1X Column scan
COL4 51 I/O CMOS / 1X Column scan
Electrical characteristics
Parameter Input
type
Output
type
Min Max Condition
V
IL
CMOS -0.5 V 0.8 V
V
IH
CMOS 2.1 V 3.0 V
V
OL
1X 0.2 V I
OL
= -1 mA
V
OH
1X 2.6 V I
OH
= 1 mA