CMX823 CML Microcircuits Programmable COMMUNICATION SEMICONDUCTORS Paging Tone Decoder D/823/3 November 2003 Provisional Issue Features Applications Decodes 32 User-Programmed Tones Two-Tone and 5/6-Tone Pagers Stores Two Lists of 32 Tones to Fast- Selective Calling (SELCALL) Systems Switch Between Tone Sets Configurable Decode Response Time Voice Pager Switching and Signalling and Decode Bandwidths Low Power: 0.75mA at 2.7V (typ.) and Revertive Paging Systems Zero-Power Powersave Mode Superior Signal to Noise Performance Wireless Local Loop Signalling Low Cost 3.58MHz Xtal/Clock Audio Tone Signalling Applications Small 16-pin TSSOP Package 1.1 Brief Description The CMX823 is a high performance, low power, audio tone decoder that can operate on low S/N signals. Each decoded tone frequency is user-defined to provide the flexibility to operate in a variety of paging, two-way radio and proprietary systems. Example systems and tones include: Motorola Quick Call series GE groups A, B and Zetron, Reach and Plectron 2-tone radio paging Motorola 5/6-tone paging and the EIA, CCIR, ZVEI1 and EEA tonesets used for HSC radio paging and SELCALL. Up to 32 user-defined decode tone frequencies from 280Hz to 3500Hz are written to an internal RAM-based FIFO. (Two separate 32-tone FIFOs are provided and support fast switching between tone sets.) Each programmed tone (entry in the list) is user-assigned to one of two (or both) tone groups. 2-tone sequence decoding is simplified by dynamically enabling one or the other tone group via a mode selection. The CMX823 asserts an interrupt on tone decoding state transitions, e.g. notone to decoded tone, decoded tone to notone, etc. STATUS and DECODED TONE PARAMETERS Registers may then be read and indicate the decoder status, the target tone decoded and its tone group. The CMX823 operates over the -40C to +85C range and is available in 16-pin TSSOP (E4) and DIL (P3) packages. 2003 CML Microsystems Plc Programmable Paging Tone Decoder CMX823 CONTENTS Section Page 1.0 Features and Applications ..................................................................1 1.1 Brief Description..................................................................................1 1.2 Block Diagram .....................................................................................3 1.3 Signal List ............................................................................................4 1.4 External Components..........................................................................6 1.5 General Description.............................................................................7 1.5.1 Software Description ..............................................................8 1.5.2 Decode Algorithm .................................................................16 1.6 Application Notes ..............................................................................17 1.6.1 General ..................................................................................17 1.7 Performance Specification................................................................18 1.7.1 Electrical Performance..........................................................18 1.7.2 Packaging..............................................................................20 2003 CML Microsystems Plc 2 D/823/3