The MB89170/170A/170L series has been developed as a general-purpose version of the F2MC*-8L family consisting of proprietary 8-bit, single-chip microcontrollers. In addition to a compact instruction set, the microcontrollers contain a great variety of peripheral functions such as timers, a serial interface, a DTMF generator, and external interrupts, making it suitable for circuit control such as required in telephones. *: F2MC stands for FUJITSU Flexible Microcontroller.