<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def resetn(self):
 """ reset a core. After a call to this function, the core is running """

        #Regular reset will kick NRF out of DBG mode
        logging.debug("target_nrf51.reset: enable reset pin")
        self.write_memory(RESET, RESET_ENABLE)
        #reset
        logging.debug("target_nrf51.reset: trigger nRST pin")
        self.reset()