CMX823E4

Product 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.

Features

• Decodes 32 User-Programmed Tones
• Stores Two Lists of 32 Tones to Fast_x0002_Switch Between Tone Set
• Configurable Decode Response Time and Decode Bandwidths
• Configurable Decode Response Time and Decode Bandwidths
• Low Power: 0.75mA at 2.7V (typ.) and 'Zero-Power' Powersave Mode
• Superior Signal to Noise Performance
• Low Cost 3.58MHz Xtal/Clock
• Small 16-pin TSSOP Package
• Two-Tone and 5/6-Tone Pagers
• Selective Calling (SELCALL) Systems
• Voice Pager Switching and Signalling