ISD94100 Series Technical Reference Manual
Sep 9, 2019
Page
260
of 928
Rev1.09
IS
D
9
410
0
S
ER
IE
S
T
E
C
HN
ICA
L
RE
F
E
RE
NCE
M
AN
U
AL
Port A-D Pull-up and Pull-down Selection Register (Px_PUSEL)
Register
Offset
R/W Description
Reset Value
PA_PUSEL
0x030
R/W PA Pull-up and Pull-down Selection Register
0x0000_0000
PB_PUSEL
0x070
R/W PB Pull-up and Pull-down Selection Register
0x0000_0000
PC_PUSEL
0x0B0
R/W PC Pull-up and Pull-down Selection Register
0x0000_0000
PD_PUSEL
0x0F0
R/W PD Pull-up and Pull-down Selection Register
0x0000_0000
31
30
29
28
27
26
25
24
PUSEL15
PUSEL14
PUSEL13
PUSEL12
23
22
21
20
19
18
17
16
PUSEL11
PUSEL10
PUSEL9
PUSEL8
15
14
13
12
11
10
9
8
PUSEL7
PUSEL6
PUSEL5
PUSEL4
7
6
5
4
3
2
1
0
PUSEL3
PUSEL2
PUSEL1
PUSEL0
Bits
Description
[2n+1:2n]
n=0,1..15
PUSELn
Port A-D Pin[n] Pull-up and Pull-down Enable Register
Determine each I/O Pull-up/pull-down of Px.n pins.
00 = Px.n pull-up and pull- down disable.
01 = Px.n pull-up enable.
10 = Px.n pull-down enable.
11 = Px.n pull-up and pull-down disable.
Note 1:
Basically, the pull-up control and pull-down control has following behavior limitation
The independent pull-up control register only valid when MODEn set as tri-state and open-
drain mode
The independent pull-down control register only valid when MODEn set as tri-state mode
When both pull-up and pull-down is set as 1 at “tri-state” mode, keep I/O in tri-state mode
Note 2:
Max. n=15 for port A/C/D
n=0..9, 13, 14, 15 for port B