The CMX615 is an integrated telecom tone generator and DTMF encoder designed for ISDN interfaces, Wireless Local Loop and Analogue to Digital Phone Conversion systems. The tone generator covers an extensive range of pre-programmed tones used in analogue phone systems (POTS). Three outputs are provided: `Ringing signals', `In-band tones or FSK data', and `12kHz/16kHz Metering pulses'. Simple software control facilitates the interface to a wide range of commonly used Cs and SLICs, enabling a comprehensive analogue telephone line presentation. The DTMF encoder generates the appropriate DTMF tones for the POTS interface. DTMF tone pairs can be encoded along with each tone singly or with other dual tone signals, such as those used in CIDCW systems and `On Hook' signalling systems. Other tone standards supported are: Fax and Modem `answer' and `originate', ITU (CCITT) `R1' and `R2' signals, and sufficient tones for simple melody generation. Communication to and from the host Controller is performed by a `C-BUS' serial interface, which is compatible with the `SPI' interface.