help needed to debug nrf51822 application?

Hello all,

I am developing application for humidity measurement using nrf51822 evaluation board which uses custom services which i have developed. I have already tested example applications given in sdk. Also my humidity application was able to run upto service discovery. After service discovery the connection gets terminated (reason: BTLE_CONNECTION_TIMEOUT ) due to received packet.<HciEvent: eventCode=0x0A>.

I am debugging my application in Keil ┬ÁVision. Is single stepping is allowed? I am noob towards debugging. Can anybody help how one should debug application step by step?