My usbasp was working fine.I could burn programme to atmega328p.But last night i wanted to cahnge the clockspeed by clock_prescale_set ( clock_div_t x ). after that it burned successfully and changed the clock speed.But I couldnot burn any new program.it shows this error massage in avr studio:
avrdude.exe: warning: cannot set sck period. please check for usbasp firmware update.
avrdude.exe: error: programm enable: target doesn't answer. 1
avrdude.exe: initialization failed, rc=-1 Double check connections and try again, or use -F to override this check.
What is the problem and how to solve it?