according to the invention the phase lock loop 202 comprises a phase frequency detector 302 a charge pump 304 a voltage controlled oscillator 306 a frequency divider 308 and a spread spectrum controller 310 the phase frequency detector 302 detects the phase and frequency relationship between the input clock signal and the feedback clock signal for generating a detecting signal and then transmitting to the charge pump 304 the charge pump 304 generates a control voltage vctrl for the voltage controlled oscillator 306 according to the detecting signal then the voltage controlled oscillator 306 generates the spread spectrum clock signal according to the control voltage vctrl for the various units in the control chip 200 for accessing memory card that needs clock signals such as the micro controller 208 the memory card interface unit and the socket in one example of the control chip 200 for accessing memory card of the invention the phase lock loop 202 generates a spread spectrum clock signal for the interface circuit and the socket furthermore the phase lock loop 202 also generates a non spread spectrum clock signal for the various control circuits such as the micro controller 208 the direct memory access unit 210 and so forth but it is noticed that those of control circuits also could use the spread spectrum clock to perform their own operation in the phase lock loop 202 the frequency divider 308 generates the feedback clock signal according to the spread spectrum clock signal the frequency of the spread spectrum signal is n times that of the feedback clock signal in which the n is a natural number since the control chip 200 for accessing memory.