SC8120B are single-chip voice synthesizing CMOS IC. They are embedded EPROM architecture, and OTP (One Time Programmable) Speech chip, Each body has one input and two I/O pins. Through accurate internal oscillation, external Rosc is unnecessary. There is only one PWM output for voice. Thus any external component is not required.Maximum 128 voice groups.Serial trigger mode maximum 127 voice groups ,moble One Group contain several steps(voice section ); Maximum 1536 steps for all the Groups. Maximum 120 seconds Voice. Each Step can be define Trigger Mode, Output Status, Voice Section, Mute length, I/O Type & Simple Programming Function. Support three mode trigger IC (Stand Alone, Serial Trigger Mode ). Easy use development system is for function selection and voice combination . PC download the ROM code by the OTP_Writer.