A control method and system according to the present invention for a displacement on demand engine estimates cylinder air charge andor predicts cylinder air charge for future cylinder interrupts. A first portion of the twin MONOS memory cell connects to a charged and floating bit line a current source formed in a second portion of the twin MONOS cell that discharges the charged bit line to form a reference signal for a sense amplifier. Secondary serial interface logic is synchronized by cycling through a plurality of delays until the output of the secondary serial interface logic equals the output of the primary serial interface logic.