There are two serial wire debug (SWD)
pins present on all devices:
- SWCLK (serial wire clock)
- SWDIO (serial wire data input/output)
After a cold start, the SWD pins are configured in SWD mode to allow a debug
connection to be established. It is possible to re-configure the SWD pins as
general purpose IO (GPIO) in software to enable use of these pins in an application
when debug support is no longer required. To disable SWD functionality, set the
DISABLE bit in the SWDCFG register in SYSCTL along with the KEY. Then configure
IOMUX for the desired functionality.
Once the SWD pin functions are
disabled, they can only be re-enabled by triggering a POR.