User manual

...the world's most energy friendly microcontrollers
2012-04-24 - Giant Gecko Family - d0053_Rev0.96 749
www.energymicro.com
Figure 32.1. Pin Configuration
Port Control
V
SS
MODEn[3:0]
DOUT
Analog connection
V
DD
Output enable
Input enable
Interrupt input
Alternate function override
Alternate function input
Alternate function output enable
Alternate function data out
Data out
DIN
Pull-down enable
Pull-up enable
Output enable
Output value
1
Glitch
suppression
filter
Filter enable
PRS
ESD
protection
ESD diode
Note
There is no ESD diode to Vdd because if using LCD voltage boost the pin voltage will be
higher than Vdd. Nevertheless there is an ESD protection block against over voltage.
32.3.1 Pin Configuration
In addition to setting the pins as either outputs or inputs, the GPIO_Px_MODEL and GPIO_Px_MODEH
registers can be used for more advanced configurations. GPIO_Px_MODEL contains 8 bit fields
named MODEn (n=0,1,..7) which control pins 0-7, while GPIO_Px_MODEH contains 8 bit fields named
MODEn (n=8,9,..15) which control pins 8-15. In some modes GPIO_Px_DOUT is also used for extra
configurations like pull-up/down and glitch suppression filter enable. Table 32.1 (p. 749) shows the
available configurations.
Table 32.1. Pin Configuration
MODEx Input Output DOUT Pull-
down
Pull-
up
Alt.
strength
Input
Filter
Description
0 Input disabled0b0000 Disabled
1 On Input disabled with pull-up
0 Input enabled0b0001
1 On Input enabled with filter
0 On Input enabled with pull-down0b0010
Enabled
Disabled
1 On Input enabled with pull-up