CMX867A CML Microcircuits Low Power COMMUNICATION SEMICONDUCTORS V.22 Modem D/867A/3 May 2008 Features Applications V.22, Bell 212A 1200/1200 or 600/600 bps DPSK Telephone Telemetry Systems V.23 1200/75, 1200/1200, 75, 1200 bps FSK Remote Utility Meter Reading Bell 202 1200/150, 1200/1200, 150, 1200 bps FSK Security Systems V.21 or Bell 103 300/300 bps FSK Industrial Control Systems DTMF/Tones Transmit and Receive Electronic Cash Terminals Powersave Standby Mode Pay-Phones Software and Hardware Compatible with CMX868A Set-Top Boxes 1. Brief Description The CMX867A is a multi-standard modem for use in telephone based information and telemetry systems. Control of the device is via a simple high speed serial bus, compatible with most types of C serial interface. The data transmitted and received by the modem is also transferred over the same serial bus. On-chip programmable Tx and Rx USARTs meeting the requirements of V.14 are provided for use with asynchronous data and allow unformatted synchronous data to be received or transmitted as 8-bit words. A high-quality DTMF decoder with excellent immunity to falsing on voice and a standard DTMF encoder are included. Alternatively, these blocks can be used to transmit and detect user-specific, programmed single and dual-tone signals, call progress signals or modem calling and answering tones. Flexible line driver and receive hybrid circuits are integrated on chip, requiring only passive external components to build a 2 or 4-wire line interface. The device also features a Hook Switch Relay Drive output and a Ring Detector circuit which continues to function when the device is in the Powersave mode, providing an interrupt which can be used to wake up the host Controller when line voltage reversal or ringing is detected. The CMX867A operates from a single 2.7 to 5.5V supply over a temperature range of -40C to +85C and is available in 24-pin TSSOP, SOIC and DIP packages. 2008 CML Microsystems Plc Low Power V.22 Modem CMX867A CONTENTS Section Page 1. Brief Description ..................................................................................... 1 2. Block Diagram......................................................................................... 3 3. Signal List................................................................................................4 4. External Components............................................................................. 5 4.1 Ring Detector Interface ............................................................. 6 4.2 Line Interface.............................................................................. 7 5. General Description.............................................................................. 10 5.1 Tx USART.................................................................................. 11 5.2 FSK and DPSK Modulators..................................................... 12 5.3 Tx Filter and Equaliser ............................................................ 13 5.4 DTMF/Tone Generator ............................................................. 13 5.5 Tx Level Control and Output Buffer....................................... 13 5.6 Rx DTMF/Tones Detectors ...................................................... 14 5.7 Rx Modem Filtering and Demodulation................................. 15 5.8 Rx Modem Pattern Detectors and Descrambler ................... 16 5.9 Rx Data Register and USART ................................................. 16 5.10 C-BUS Interface........................................................................ 18 5.10.1 General Reset Command ........................................... 18 5.10.2 General Control Register ........................................... 20 5.10.3 Transmit Mode Register............................................. 22 5.10.4 Receive Mode Register............................................... 26 5.10.5 Tx Data Register.......................................................... 28 5.10.6 Rx Data Register ......................................................... 28 5.10.7 Status Register............................................................ 29 5.10.8 Programming Register ............................................... 32 6. Application Notes ................................................................................. 35 6.1 V.22 Calling Modem Application ............................................ 35 6.2 V.22 Answering Modem Application...................................... 36 6.3 Reference Diagrams ................................................................ 36 7. Performance Specification................................................................... 37 7.1 Electrical Performance............................................................ 37 7.1.1 Absolute Maximum Ratings....................................... 37 7.1.2 Operating Limits ......................................................... 37 7.1.3 Operating Characteristics.......................................... 38 7.2 Packaging ................................................................................. 45 It is always recommended that you check for the latest product datasheet version from the Datasheets page of the CML website: www.cmlmicro.com . 2008 CML Microsystems Plc 2 D/867A/3