CML Microcircuits CMX866, Manual, Page: 2 / 53

V.22 bis Modem with AT Commands CMX866
©
2008 CML Microsystems Plc 2 D/866/5
CONTENTS
Section Page
1.1 Brief Description .................................................................................................1
1.2 Block Diagram .....................................................................................................3
1.3 Signal List ............................................................................................................4
1.4 External Components.........................................................................................6
1.4.1 Ring Detector Interface .........................................................................8
1.4.2 Line Interface..........................................................................................9
1.4.3 Serial Interface .....................................................................................11
1.4.4 RESETN pin ..........................................................................................12
1.5 General Description..........................................................................................13
1.5.1 Internal Structure .................................................................................13
1.5.2 Operating States and Data Flow.........................................................14
1.5.3 Functional Description ........................................................................16
1.5.4 AT Command and Register Set ..........................................................17
1.5.4.1 AT Command and S-Register Summary...............................17
1.5.4.2 General Description of AT Commands.................................19
1.5.4.3 AT Commands in Detail..........................................................20
1.5.4.4 Extended AT Commands .......................................................23
1.5.4.5 S-Registers ..............................................................................26
1.5.4.6 Result Codes ...........................................................................30
1.5.5 Tx USART..............................................................................................30
1.5.6 FSK and QAM/DPSK Modulators .......................................................32
1.5.7 Tx Filter and Equaliser ........................................................................33
1.5.8 DTMF/Tone Generator .........................................................................33
1.5.9 Tx Level Control and Output Buffer...................................................33
1.5.10 Rx DTMF/Tones Detectors ..................................................................34
1.5.11 Rx Modem Filterering and Demodulation..........................................35
1.5.12 Rx Modem Pattern Detectors and Descrambler ...............................36
1.5.13 Rx Data Register and USART .............................................................36
1.6 Application Notes .............................................................................................38
1.6.1 Hardware Interface ..............................................................................38
1.6.2 Calling
Modem AT Commands ...........................................................43
1.6.3 Answering Modem AT Commands ....................................................43
1.6.4 RS232 Transaction Sequence ............................................................44
1.7 Performance Specification...............................................................................45
1.7.1 Electrical Performance ........................................................................45
1.7.1.1 Absolute Maximum Ratings...................................................45
1.7.1.2 Operating Limits .....................................................................45
1.7.1.3 Operating Characteristics......................................................46
1.7.2 Packaging .............................................................................................52
It is always recommended that you check for the latest product datasheet version from the
Datasheets page of the CML website: [www.cmlmicro.com].