SWM Basic configuration

Once configured, no clocks are needed for the switch matrix to function. The system clock is needed only to write to or read from the pin assignment registers. After the switch matrix is configured, disable the clock to the switch matrix block in the SYSAHBCLKCTRL register.

Before activating a peripheral or enabling its interrupt, use the switch matrix to connect the peripheral to external pins.

The boot loader assigns the SWD functions to pins PIO0_2 and PIO0_3. If the user code disables the SWD functions through the switch matrix to use the pins for other functions, the SWD port is disabled.

Note: For the purpose of programming the pin functions through the switch matrix, every pin except the power and ground pins is identified in a package-independent way by its GPIO port pin number.