W90P710_05 Datasheet, PDF (492/526 Pages) Winbond – 16/32-bit ARM microcontroller

W90P710
7.21.2 Register Description
Keypad Controller Configuration Register (KPI_CONF)
REGISTER
KPICONF
ADDRESS
0xFFF8_8000
R/W
DESCRIPTION
R/O key pad configuration register
RESET VALUE
0x0000_0000
31
30
23
22
RESERVED
15
14
7
6
29
21
ENCODE
13
5
28
27
RESERVED
20
19
ODEN
KPSEL
12
11
DBTC
4
3
PRESCALE
26
18
ENKP
10
2
25
24
17
16
KSIZE
9
8
1
0
BITS
[31:22]
[21]
[20]
[19]
RESERVED
ENCODE
ODEN
KPSEL
DESCRIPTION
-
Enable Encode Function
If an auxiliary 8 to 3 encoder is used to minimize keypad interface
pin counts, user can connect encoder data to KPI_COL[2:0] and
indicator flag (low active) to KPI_COL[3].
1 = enable encoder function
0 = default. (8 column inputs)
Open Drain Enable
If there are more than one key are pressed in the same column, then
“short-circuit” will appear between active scan and inactive scan row.
Software can set this bit HIGH to enable scan output KPI_ROW[3:0]
pins work as “open-drain” to avoid the “short-circuit”.
1 = Open drain
0 = push-pull driver
Key pad select
W90P710 provide two interfaces for keypad function. Software
should set this bit to select which interface is used to connect
keypad matrix.
1 = pin#23 ~#34 is used as keypad interface
0 = pin #81~88 and #19,#20 are used as keypad interface
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