The CMX602B is a low power CMOS device used for the reception of physical layer signals in Bellcore's Calling Identity Delivery (CID) and Calling Identity on Call Waiting (CIDCW) systems, British Telecom Calling Line Identification Service (CLIP), the Cable Communications Association's Caller Display Services (CDS), and similar evolving services. This device includes a 'zero-power' ring or line polarity reversal detector, a dual-tone (2130Hz plus 2750Hz) internally timed CPE Alerting Signal (CAS) detector, and a 1200-baud FSK Bell202/V23 compatible asynchronous data demodulator with data retiming circuitry which removes the need for a UART in the associated C.