7.2 Pin description
The pin description table Table 4 shows the pin functions that are fixed to specific pins on
each package. These fixed-pin functions are selectable between GPIO and the
comparator, SWD, RESET, and the XTAL pins. By default, the GPIO function is selected
except on pins PIO0_2, PIO0_3, and PIO0_5. JTAG functions are available in boundary
scan mode only.
Movable function for the I2C, USART, SPI, and SCT pin functions can be assigned
through the switch matrix to any pin that is not power or ground in place of the pin’s fixed
functions.
The following exceptions apply:
For full I2C-bus compatibility, assign the I2C functions to the open-drain pins PIO0_11 and
PIO0_10.
Do not assign more than one output to any pin. However, more than one input can be
assigned to a pin. Once any function is assigned to a pin, the pin’s GPIO functionality is
disabled.
Pin PIO0_4 triggers a wake-up from Deep power-down mode. If you need to wake up
from Deep power-down mode via an external pin, do not assign any movable function to
this pin.
The JTAG functions TDO, TDI, TCK, TMS, and TRST are selected on pins PIO0_0 to
PIO0_4 by hardware when the part is in boundary scan mode.
