EFM32WG Datasheet, PDF (752/834 Pages) List of Unclassifed Manufacturers – The EFM32WG Wonder Gecko is the ideal choice for demanding 8-, 16-, and 32-bit energy sensitive applications.

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Figure 32.3. Push-Pull Configuration
Out put Enable
DOUT
DIN
Input Enable
When MODEn is 0110 or 0111, the pin operates in open-source mode, the latter with a pull-down resistor.
When driving a high value in open-source mode, the pull-down is disconnected to save power.
For the remaining MODEn values, i.e. MODEn >= 1000, the pin operates in open-drain mode as shown
in Figure 32.4 (p. 752) . In open-drain mode, the pin can have an input filter, a pull-up, different driver
strengths or any combination of these. When driving a low value in open-drain mode, the pull-up is
disconnected to save power.
Figure 32.4. Open-drain
DIN
DOUT
Filt er enable
Glit ch
suppression
filter
V_DD
Opt ional
pull-up
V_SS
When MODEn=0b0101 or 0b11xx, the output driver uses the drive strength specified in DRIVEMODE
in GPIO_Px_CTRL. In all other output modes, the drive strength is set to 6 mA.
32.3.1.1 Configuration Lock
GPIO_Px_MODEL, GPIO_Px_MODEH, GPIO_Px_CTRL, GPIO_Px_PINLOCKN, GPIO_EXTIPSELL,
GPIO_EXTIPSELH, GPIO_INSENSE and GPIO_ROUTE can be locked by writing any other value
than 0xA534 to GPIO_LOCK. Writing the value 0xA534 to the GPIOx_LOCK register unlocks the
configuration registers.
In addition to configuration lock, GPIO_Px_MODEL, GPIO_Px_MODEH, GPIO_Px_DOUT,
GPIO_Px_DOUTSET, GPIO_Px_DOUTCLR, and GPIO_Px_DOUTTGL can be locked individually for
each pin by clearing the corresponding bit in GPIO_Px_PINLOCKN. Bits in the GPIO_Px_PINLOCKN
register can only be cleared, they are set high again after reset.
32.3.2 EM4 Wake-up
It is possible to wake-up from EM4 through reset triggered from any of up to 6 selectable GPIO pins.
For the wake-up logic to work correctly, EM4 retention needs to be enabled before entering EM4, as
described in Section 32.3.3 (p. 753) The wake-up request can be triggered through the pins by
enabling the corresponding bit in the GPIO_EM4WUEN register. When EM4 wake-up is enabled for the
pin, the input filter is enabled during EM4. This is done to avoid false wake-up caused by glitches. In
addition, the polarity of the EM4 wake-up request can be selected using the GPIO_EM4WUPOL register.
2013-05-08 - Wonder Gecko Family - d0233_Rev0.50
752
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