The MSM64P155 (1.5 V)/64P155L (3.0 V) is a one-time-programmable ROM version product, which has one-time PROM (OTP) as internal program memory. On the other hand, the MSM64155 is a mask ROM-version product, which has mask ROM as internal program memory. Unlike the mask ROM-version MSM64155 which has a P-well CMOS structure, the MSM64P155/ 64P155L has been fabricated with the N-well CMOS-structured EPROM process technology. Therefore, the MSM64P155/64P155L differs from the MSM64155 in the polarity of the power supply for LCD bias generation and in the external circuit structure. Unlike the mask ROM-version product, the MSM64P155/64P155L cannot be supplied in the form of a chip. The MSM64P155/64P155L is an OTP-version product used to evaluate an application program.