I was developing an application for LPC81x and needed this function, but it does not exist.
Here a suggestion to create one..
/* unassign a movable pin function to a physical pin */
void Chip_SWM_MovablePinUnAssign(CHIP_SWM_PIN_MOVABLE_T movable)
{
uint32_t temp;
int pinshift = PINSHIFT(movable), regIndex = PINASSIGN_IDX(movable);
temp = LPC_SWM->PINASSIGN[regIndex] & (~(0xFF << pinshift));
LPC_SWM->PINASSIGN[regIndex] = temp | (0xFF << pinshift);
}
regards,