CTM8B5X series is an EPROM based 8-bit microcontroller which employs a full CMOS technology enhanced with low-cost, high speed and high noise immunity.  Watchdog Timer, RAM, EPROM, tri-state I/O port, power down mode, and real time programmable clock/counter are integrated into this chip.CTM8B5X contains 33 instructions, all are single cycle except for program branches which take two cycles.

On chip memory is available with 512x14 bits of EPROM for CTM8B54E/55E, 1Kx14 bits of EPROM for CTM8B56E, 2Kx14 bits of EPROM for CTM8B57E and 24 to 72 bytes of static RAM.