System in package integrated circuit with self-generating reference voltage

A system in package (SIP) integrated circuit which self-generates an input reference voltage, comprising:

• a logic circuit chip, comprising a plurality of output pins for generating a plurality of output signals;
• and
• a memory chip, comprising a plurality of input circuits for receiving the plurality of output signals generated by the logic circuit chip, the memory chip further comprising a voltage generator which generates the input reference voltage according to an external voltage;
• wherein each input circuit of the memory chip comprises a comparator, the comparator comprises a first input end and a second input end, the first input end receives an output signal out of the plurality of the output signals, the second input end receives the input reference voltage generated from the voltage generator of the memory chip, the comparator generates an input signal for the memory chip according to the output signal and the input reference voltage, and the memory chip is compatible to a DDR standard.