Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
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631
PMODE[1:0]
POTYPE
PUPD[1:0]
I/O configuration
1
0
1
Alternate function
open-drain
+
pull-up
1
1
0
Alternate function
open-drain
+
pull-down
1
1
1
Reserved
00
x
0
0
Input floating
x
0
1
Input
pull-up
x
1
0
Input
pull-down
x
1
1
Reserved
11
x
0
0
Analog
x
0
1
Reserved
x
1
0
x
1
1
The input and output characteristics of I/O under different configurations are shown in the following table
:
Table 5-2 Input and output characteristics of different configurations
Feature
GPIO Input
GPIO Output
Analog
Alternate
function
Output buffer
Disabled
Enabled
Disabled
Configure
according to
peripheral
functions
Schmitt trigger
Enabled
Enabled
Disabled
,
Output is forced to 0
Enabled
PULL UP/DOWN/FLOAT
Configurable
Configurable
Disabled
Configurable
OPEN DRAIN
Disabled
Configurable, GPIO
outputs 0 when the
output data is "0", and
GPIO high impedance
when "1"
Disabled
Configurable,
GPIO outputs 0
when the output
data is "0", and
GPIO high
impedance
when "1"
PUSH PULL MODE
Disabled
Configurable, when the
output data is "0", the
GPIO outputs 0, and
when the output data is
"1", the GPIO outputs 1
Disabled
Configurable,
GPIO outputs 0
when the output
data is "0", and
GPIO high
impedance
when "1"
Input data register (I/O status)
Readable
Readable
Reads out 0
Readable
Output data register(Output value)
Invalid
Readable and writable
Invalid
Readable