...the world's most energy friendly microcontrollers
2014-07-02 - Tiny Gecko Family - d0034_Rev1.20
468
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MODEn
Input
Output
DOUT
Pull-
down
Pull-
up
Alt.
strength
Input
Filter
Description
1
On
Input enabled with pull-up
0
On
On
Input enabled with pull-down and
filter
0b0011
1
On
On
Input enabled with pull-up and filter
0b0100
x
Push-pull
0b0101
Push-pull
x
On
Push-pull with alt. drive strength
0b0110
x
Open-source
0b0111
Open
Source
(Wired-OR)
x
On
Open-source with pull-down
0b1000
x
Open-drain
0b1001
x
On
Open-drain with filter
0b1010
x
On
Open-drain with pull-up
0b1011
x
On
On
Open-drain with pull-up and filter
0b1100
x
On
Open-drain with alt. drive strength
0b1101
x
On
On
Open-drain with alt. drive strength
and filter
0b1110
x
On
On
Open-drain with alt. drive strength
and pull-up
0b1111
Open Drain
(Wired-
AND)
x
On
On
On
Open-drain with alt. drive strength,
pull-up and filter
MODEn determines which mode the pin is in at a given time. Setting MODEn to 0b0000 disables the
pin, reducing power consumption to a minimum. When the output driver is disabled, the pin can be used
as a connection for an analog module (e.g. ADC, LCD...). Input is enabled by setting MODEn to any
value other than 0b0000. The pull-up, pull-down and filter function can optionally be applied to the input,
see Figure 28.2 (p. 468) .
The internal pull-up resistance, R
PU
, and pull-down resistance, R
PD
, are defined in the device datasheet.
When the filter is enabled it suppresses glitches with pulse widths as defined by the parameter t
IOGLITCH
in the device datasheet.
Figure 28.2. Tristated Output with Optional Pull-up or Pull-down
V
DD
DIN
Opt ional
pull- up
V
SS
Opt ional
pull- down
Input enable
Analog connect ion
Glit ch
suppression
filt er
Filt er enable
When MODEn=0b0100 or MODEn=0b0101, the pin operates in push-pull mode. In this mode, the pin
is driven either high or low, dependent on the value of GPIO_Px_DOUT. The push-pull configuration is
shown in Figure 28.3 (p. 469) .
Summary of Contents for EFM32TG
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