DE3032149C2 - Tone generator - Google Patents

Description

characterized in that

- all first inputs of the AND gates (22-1

22-m) are connected to only a single clock signal generator (24) which supplies a clock signal (Ti-TJ for each first input) in a time-divided sequence, and that

- the second entrances of the UliD-Glleder (22-1

22-m) are each connected to a parallel output of a register (20).

2. Tone generator according to claim 1, characterized in that it lasts between the output of the OR gate (28) and the device (26) an inverter (30) is arranged.

3. Tone generator according to claim 1 or 2, characterized characterized in that the device (26) is a piezo oscillator.

4. Tone generator according to claim 1, 2 or 3, characterized in that the register (20) has a Has serial input for receiving serial data.

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The invention relates to a tone generator according to the preamble of claim 1.

Such a tone generator is well known and has several oscillators to excite a loudspeaker with signals of different frequencies. These The design is intrinsically complicated and requires a complex control circuit.

The invention is based on the object of a purely To create a digitally working tone generator with a reduced number of oscillators.

The solution to the task at hand is in the characteristic Part of claim 1 specified. Advantageous refinements of the invention are the sub-addresses refer to.

The tone generator according to the invention with several AND gates, the first input with a Periodic signal generating clock signal generator is connected, and its second input control signals receives, an OR element whose input is connected to the outputs of all AND elements and with a device connected to the output of the OR gate for generating a tone as a function of of the output signal of the OR element is characterized by the fact that all the first inputs of the AND elements connected to only a single clock signal generator are, which each have a clock signal in a time-subdivided sequence supplies for each first input, and that the second inputs of the AND gates each with a parallel output of a register are connected.

In principle, shift registers with a serial input and parallel outputs are known, cf. Example Dworatschek, Introduction to Data Processing, 3rd Edition, 1970, Walter de Gruyter and Co., Page 61 and page 248. In addition, there are also circuit arrangements well known, which consist of several AND gates, the outputs of which on a common OR gate are connected with a subsequent inverter, for example from Texas Instruments Integrated Circuit Data Book, 1st Edition, 1971, Rare 9-339 through 9-350.

A special feature of the tone generator is that it can only generate different tones requires a single oscillator. The tone generator generates a square wave signal with the desired frequency sequence generated to excite a loudspeaker or piezo oscillator.

A single oscillator is used, which generates a clock signal in a time-division multiplexed sequence generated. Bit signals are serially supplied to a register, temporarily stored therein, and then in parallel fed to a gate circuit, gives way, consists of several AND gates, each of which has one Bit in the register is assigned. Each AND element receives a clock signal in a time-divided sequence, and the The resulting output signals of the AND gates are sent to a loudspeaker via an OR gate fed.

An embodiment having the features of the invention will now be referred to explained in more detail on a drawing. It shows:

Fig. 1 is a block diagram of a conventional one Tone generator,

Fig. 2 is a block diagram of a tone generator according to the invention,

F i g. 3 shows an example of a signal diagram for the tone generator according to F1 g. 2, and

Flg. 4 (A) and 4 (B) representations of output signals of the tone generator according to FIG. 2.

A conventional tone generator shown schematically in FIG. 1 comprises a plurality of oscillators 10-1 to 10-n for generating various signals with different courses, which are each fed to one of several AND gates 12-1 to 12-n. Depending on bit signals, the individual AND gates 12-1 to 12-n receive selection signals S _t to S _n in order to emit output signals which are used to excite a loudspeaker 14 and which are fed to it via an OR gate 16 with an inverter 18. Thus, the conventional tone generator requires a plurality of oscillators 10 of the number n.

The In FI g. 2 The embodiment of a tone generator according to the invention, shown in the form of a schematic block diagram, contains an m-Blt-Rcgister 20 with serial input and parallel outputs, into which data (bit signals) are fed in series, temporarily stored therein and in parallel at AND gates 22-1 to 22-m are output, of which one AND element corresponds to one of the m bits of the register 20 and is assigned to it. A clock signal generator 24 produces in a time divided sequence timing signals T \ ... T _m, which are the AND gates 22-1 to 22-m supplied so that the respective AND gates corresponding bit Ausgangsslgnale by switching from the register 20 and via a OR gate 28 with inverter 30 one

Use it to energize speaker 26.

The in series supplied data, for example, D \ = 0, _D2 = 1, _D1 = 0, ... D _m _ = 0, D _m = 1, are temporarily stored at the corresponding bit positions in the registers 20 and then delivered in parallel to AND gates 22-1 to 22-m . The pulse shapes of the supplied clock signals T ₁ to T _n , as well as the output signals P leaving the OR gate 28, are shown in Ir _{1 in} FIG. 3. Accordingly, the loudspeaker 26 is excited on the way via the register 20 with a series input and parallel outputs by a rectangular signal P with the desired frequency sequence.

Since the data (bit signals) are fed into the register 20 in series, a simple control signal line is sufficient.

In Figs. 4 (A) and 4 (B) still other examples of square wave output signals are given, as indicated by the Tone generator can be generated.

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Claims (1)

Patent claims: 1. Tone generator, with - several AND gates (22-i 22-m), whose the first input is connected to a clock signal generator generating a periodic signal, and whose second input receives control signals, - An OR gate (28), the input of which with the Outputs of all AND gates (22-1 22-m) connected, and with - A device (26) connected to the output of the OR gate (28) for generating a Tones depending on the output signal of the is OR gate (28),