JPH073983B2 - Telephone semiconductor integrated circuit - Google Patents

Description

The present invention relates to a telephone dialer semiconductor integrated circuit (hereinafter referred to as a dialer IC) or an integrated circuit having a dial function (hereinafter referred to as an IC).

[Outline of Invention]

This invention relates to a rewritable semiconductor memory device (hereinafter referred to as RAM
In the dialer IC that stores a telephone number or that has a similar dial function, a data end code (hereinafter referred to as an end code) is written to the first digit or digits of the telephone number when the power is turned on. This prevents a wrong call when an unopened address is called by mistake.

[Conventional technology]

When a conventional dialer IC for a telephone has a memory, there are one that clears the memory by manual operation every time the power is turned on and one that accesses the memory by software and initializes it.

[Problems to be solved by the invention]

However, manually clearing the memory is troublesome, and there is a possibility that an erroneous operation may be involved. In addition, in order to initialize the memory by software, the operation of accessing the memory while changing the address and writing the initialization data must be repeated by the number of stored telephone numbers, and the circuit for that is complicated and time-consuming. It had the drawback of taking up too much.

Therefore, according to the present invention, in order to solve such drawbacks of the related art, the memory is initialized by hardware when the power is turned on, so that the dialer can be easily and highly reliable.
The purpose is to prevent wrong phone calls due to incorrect operation of the IC.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides an initialization signal input terminal in a RAM memory cell for storing the first digit or a plurality of digits of a telephone number, and uses the power-on reset signal or the like when the power is turned on. The end code is written in.

[Action]

Telephone dialer I with built-in RAM configured as above
In C, when an address without a telephone number is accessed,
The end code is read, the output of the end code detection gate is input to the control circuit, the access to the RAM is immediately stopped, and the output of the output generation circuit is also stopped. For this reason, wrong phone calls can be prevented.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.
In FIG. 1, the outputs 2 and 3 of the RAM address counter 1 are
It is inputted to the Y address decoder 4 and the X address decoder 5, respectively. The RAM 6 with the initialization signal input terminal is located in the first digit to the plural digits of each telephone number storage address, and the other RAM 7 constitutes the entire memory. The output 9 of the pulse generation circuit 8 is input to the RAM 6 with the initialization signal input terminal. The output 9 is also input to the control circuit 10 to initialize the control unit. Memory output 11 is REA
Input from the D / WRITE buffer 12 to the output generation circuit 13 and the end code detection gate 14. The output 15 of the detection gate 14 is input to the control circuit 10, and the outputs 16, 17, and 18 of the control circuit 10 are input to the output generation circuit 13, the READ / WRITE buffer 12, and the address counter 1, respectively. As a result, as soon as the end code is detected in the RAM output, output, RAM reading, and address counter increment stop. input signal
19 is normally input from an external keyboard (not shown) through a keyboard interface circuit (not shown) provided on the same integrated circuit.

2 (a) is a first detailed circuit diagram of the RAM 6, and similarly, FIGS. 2 (b) and 2 (c) are second and third detailed circuit diagrams of the RAM 6, respectively.

〔The invention's effect〕

As described above, the present invention has an effect that it is possible to prevent an erroneous call of a telephone dialer IC by initializing the memory with a simple configuration.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIGS. 2 (a), (b), and (c) are first, second, and third of a RAM with an initialization signal input terminal according to the present invention, respectively. 3 is a detailed circuit diagram of FIG. 6 ... RAM with initialization signal input terminal 7 ... RAM 8 ... Pulse generator circuit 10 ... Control circuit 13 ... Output generator circuit 14 ... End code detection gate

Claims (4)

[Claims] 1. A circuit for generating a pulse when the power is turned on and a rewritable storage device with an initialization signal input terminal, the contents of which are initialized by the output of the pulse generation circuit, in the first digit of each telephone number storage address. To a rewritable memory device having a plurality of first digits, a detection gate for detecting a data end code from the output of the rewritable memory device, and a control for receiving the output of the detection gate and stopping the reading of the memory device Circuit, and an output signal generation circuit controlled by the control circuit to generate an output corresponding to the data read from the storage device, and the generation of the output is stopped by the control circuit receiving the output of the detection gate And a semiconductor integrated circuit for telephones. 2. The storage device with an initialization signal input terminal is constituted by a two-input NR gate whose output is connected to another input and an inverter, according to claim 1. Telephone semiconductor integrated circuit. 3. The storage device with an initialization signal input terminal is configured by a two-input NAND gate whose output is connected to another input and an inverter, according to claim 1. Telephone semiconductor integrated circuit. 4. A storage device with an initialization signal input terminal is electrically connected between a flip-flop composed of a pair of inverters whose outputs are connected to other inputs, and between one output of the flip-flop and a certain potential. 2. The telephone semiconductor integrated circuit according to claim 1, wherein the semiconductor integrated circuit comprises a connected switching element.