Speedy DSP Permits Concurrent Operation Of Answering Machine & Other Functions
High-end digital telephone answering machine, caller ID/call waiting, and full-duplex speakerphone functions have been integrated onto a single digital signal processor that runs at up to 100 MIPS. The chip delivers up to 15 minutes of answering machine recording time using algorithms developed by Bell Labs. In addition, the DSP's high processing speed permits the concurrent operation of the above telephony functions, as well as enabling the digital recording of a phone conversation while two people are talking to each other on a speakerphone. The DSP1609ND, a software-enhanced version of the DSP1609 introduced earlier this year, is a 16-bit, fixed-point DSP that comes in a 5V, 10-ns instruction cycle time, 100-MIPS version and a 3.3V, 12.5-ns, 80-MIPS version. Both come packaged in 44-pin PLCCs.