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From: pec@necntc.nec.com (Paul Cohen)
Newsgroups: sci.electronics
Subject: Re: Sine wave generator
Keywords: Sine wave generator
Message-ID: <28373@necntc.nec.com>
Date: 21 Jul 89 13:18:54 GMT
References: <790@serene.UUCP>
Reply-To: pec@necntc.UUCP (Paul Cohen)
Organization: NEC Electronics Inc.  Natick, MA 01760
Lines: 20

NEC has a line of speech generation components which can also be
programmed to generate various tones of which a sine wave (up to about 
3 KHz) would be the simplest example.  DTMF signals are examples of 
somewhat more complex sounds that are possible.  Code for the DTMF 
signals is available as a library.  Since so many frequencies are 
possible, sine waves would have to be custom programmed, but this is 
not difficult.

An open question for the readers of this news-group: what frequencies of
sine waves do you want?   We could add them to our library fairly
easily.

The parts, uPD775x (x = 5, 6, 7) come as mask ROM parts with various
sizes of ROM.  There is also a version, uPD7759 which uses external
memory (RAM or ROM) and a one-time programmable version the uPD77P56.
All of these parts include a D/A and filter circuitry and require only
an external ceramic resonator for clocking.

Call (508) 655-8833 
or   (800) 366-3782 for more information.