The TPS51216-EP has two input pins, S3 and S5, to provide simple control scheme of power state. All of VDDQ, VTTREF and VTT are turned on at S0 state (S3 = S5 = high). In S3 state (S3 = low, S5 = high), VDDQ and VTTREF voltages are kept on while VTT is turned off and left at high impedance state (high-Z). The VTT output floats and does not sink or source current in this state. In S4/S5 states (S3=S5=low), all of the three outputs are turned off and discharged to GND according to the discharge mode selected by MODE pin. Each state code represents as follow; S0 = full ON, S3 = suspend to RAM (STR), S4 = suspend to disk (STD), S5 = soft OFF. (See Table 8-1)