26.3.1.1 Over Voltage Tolerance
Over voltage capability is available for most pins. If available, it allows the pin to be used at either the minimum of VDDIO + 2V and
5.5V (for 5V tolerant pads) or the minimum of VDDIO + 2V and 3.8V (for non-5V tolerant pads). The datasheet specifies which pins can
be used as 5V tolerant pins. Default over voltage is enabled for each pin supporting that feature. Over voltage tolerance can be disa-
bled on a per pin basis. The over voltage tolerance feature applied to the selected pins is configured in the GPIO_Px_OVTDIS register.
Disabling the over voltage tolerance for a pin will provide less distortion on that pin, which is useful when the pin is used as analog
input.
26.3.1.2 Alternate Port Control
The Alternate Port Control allows for additional flexibilty of port level settings. A user may setup two different port configurations (normal
and alternate modes) and select which is applied on a pin by pin bases. For example you may configure half of port A to use the low
drive strength setting (normal mode) while the other half uses high drive strenght (alternate mode).
Alternate port control is enabled when MODEn is set to any of the ALT enumared modes (ie. PUSHPULLALT). When MODEn is an
alternate mode, the pin uses the alternalte port control values specified in the DINDISALT,SLEWRATEALT, and DRIVESTRENGTHALT
fields in GPIO_Px_CTRL. In all other modes, the port control values are used from the DINDIS,SLEWRATE, and DRIVESTRENGTH
fields in GPIO_Px_CTRL.
26.3.1.3 Drive Strength
The drive strength can be applied to pins on a port-by-port basis. The drive strength applied to pins configured using normal MODEn
settings can be controlled using the DRIVESTRENGTH field in GPIO_Px_CTRL. The drive strength applied to pins configured using
alternate MODEn settings can be controled using the DRIVESTRENGTHALT field.
26.3.1.4 Slewrate
The slewrate can be applied to pins on a port-by-port basis. The slewrate applied to pins configured using normal MODEn settings can
be controlled using the SLEWRATE fields in GPIO_Px_CTRL. The slewrate applied to pins configured using the alternate MODEn set-
tings can be controlled using the SLEWRATEALT field.
26.3.1.5 Input Disable
The pin inputs can be disabled on a port-by-port basis. The input of pins configured using the normal MODEn settings can be disabled
by setting DINDIS in GPIO_Px_CTRL. The input of pins configured using the alternate MODEn settings can be disabled by setting DIN-
DISALT.
26.3.1.6 Configuration Lock
GPIO_Px_MODEL, GPIO_Px_MODEH, GPIO_Px_CTRL, GPIO_Px_PINLOCKN, GPIO_Px_OVTDIS, GPIO_EXTIPSELL, GPIO_EX-
TIPSELH, GPIO_EXTIPINSELL, GPIO_EXTIPINSELH, GPIO_INSENSE, GPIO_ROUTEPEN, and GPIO_ROUTELOC0 can be locked
by writing any value other than 0xA534 to GPIO_LOCK. Writing the value 0xA534 to the GPIOx_LOCK register unlocks the configura-
tion registers.
In addition to configuration lock, GPIO_Px_MODEL, GPIO_Px_MODEH, GPIO_Px_DOUT, GPIO_Px_DOUTTGL, and GPIO_Px_OVT-
DIS can be locked individually for each pin by clearing the corresponding bit in GPIO_Px_PINLOCKN. When a bit in the GPIO_Px_PIN-
LOCKN register is cleared, it will stay cleared until reset.
EFM32JG1 Reference Manual
GPIO - General Purpose Input/Output
silabs.com
| Smart. Connected. Energy-friendly.
Preliminary Rev. 0.6 | 877