The OM5234 and OM5284 single-chip 8-bit microcontrollers are manufactured in an advanced CMOS process and are derivatives of the 80C51 microcontroller family. The OM5234 and OM5284 are pre-programmed devices for specific applications. Unless
specifically stated otherwise, all references to OM5234 apply equally to OM5284.

The OM5234 contains a non-volatile 16k ×8 read-only program memory, a volatile 256 ×8 read/write data memory, four 8-bit I/O ports, two 16-bit timer/event counters (identical to the timers of the 80C51), a multi-source, two-priority-level, nested interrupt structure,
UART and on-chip oscillator and timing circuits.