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2016-04-28 - Giant Gecko Family - d0053_Rev1.20
762
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It is possible, but not recommended to select two or more peripherals as output on the same pin. These
signals will then be OR'ed together. However, TIMER CCx and CDTIx outputs, which are routed as
alternate functions, have priority, and will never be OR'ed with other alternate functions. The reader is
referred to the pin map section of the device datasheet for more information on the possible locations
of each alternate function and any priority settings.
32.3.4.1 Serial Wire Debug Port Connection
The SW Debug Port is routed as an alternate function and the SWDIO and SWCLK pin connections
are enabled by default with internal pull-up and pull-down resistors, respectively. It is possible to disable
these pin connections (and disable the pull resistors) by setting the SWDIOPEN and SWCLKPEN bits
in GPIO_ROUTE to 0.
WARNING: When the debug pins are disabled, the device can no longer be accessed by a debugger. A
reset will set the debug pins back to their default state as enabled. If you do disable the debug pins, make
sure you have at least a 3 second timeout at the start of your program code before you disable the debug
pins. This way the debugger will have time to halt the device after a reset before the pins are disabled.
The Serial Wire Viewer Output pin (SWO) can be enabled by setting the SWOPEN bit in GPIO_ROUTE.
This bit can also be routed to alternate locations by configuring the LOCATION bitfield in GPIO_ROUTE.
32.3.4.2 ETM Trace Ports
There are five trace pins available on the device. One trace clock which can be enabled by setting the
TCLKPEN bitfield in GPIO_ROUTE. The four data pins can be enabled individually by setting TD0PEN,
TD1PEN, TD2PEN, and TD3PEN respectively in GPIO_ROUTE. It is possible to choose which pins
the trace data will be exported to. The lowest trace bit will be routed to the first enabled trace pin. For
example, if the ETM data port size is 2 bits and TD0 and TD3 are enabled, will make bit 0 be routed
to TD0 while bit 1 will be routed to TD3.
Both the TCLK and all the TD pins can also be routed to alternate locations by configuring the
ETMLOCATION bitifeld in GPIO_ROUTE.
32.3.4.3 Analog Connections
When using the GPIO pin for analog functionality, it is recommended to disable the digital output and
set the MODEn in GPIO_Px_MODEL/GPIO_Px_MODEH equal to 0b0000 to disable the input sense
and pull resistors.
32.3.5 Interrupt Generation
The GPIO can generate an interrupt from the input of any GPIO pin on a device. The interrupts have
asynchronous sense capability, enabling wake-up from energy modes as low as EM3, see Figure 32.6 (p.
762) .
Figure 32.6. Pin n Interrupt Generation
IRQ_GPIO_EVEN/
IRQ_GPIO_ODD
PAn
EXTIRISE[n]
IEN[n]
EXTIPSELn[2:0]
PBn
PCn
PDn
PEn
IF[n]
set
clear
IFS[n]
IFC[n]
wakeup
PFn
EXTIFALL[n]
PRS
Odd/ even input s
Synch
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