nRF51 Flexible GPIO Feature

Question

Hi, 
 I'm trying to make the nRF module work with an older IO demo board. Does the flexible GPIO system via pin crossbar allow you to modify the pin assignments of the SWDIO or SWDCLK pins? In the description of the flexible GPIO it mentions that the digital pin operations for the 2-wire can be modified, if it is possible how would I go about modifying these pin assignments? 
 Thanks

Ole Morten · Accepted Answer

There's a difference between the SWD interface (used for programming and debugging) and the TWI interface (Two-Wire Interface, I2C-compatible, used for external sensors and similar). 
 The TWI interface can be mapped to any pin using the PSELSDA and PSELSCK registers in the TWI peripheral, but there is no way to remap the SWD interface to any other pin than the default ones.