The CMX605 is an integrated telecom tone generator and DTMF encoder/decoder designed for ISDN interfaces, Wireless Local Loop and Analog to Digital Telephone Conversion systems. The tone generator covers an extensive range of pre-programmed tones used in analog telephone 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 analog telephone line presentation. The DTMF encoder/decoder presents the digital line interface with DTMF dialing information received from the telephone user and 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' signaling 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 C is performed by a `C-BUS' interface which is compatible with common serial interfaces such as: SCI, SPI, and Microwire.