JPS5928790A - Subscriber circuit of telephone set - Google Patents

Abstract

PURPOSE:To decrease the load of a processor, by providing a counter counting the change in a line signal in a subscriber circuit and counting the change in the signal with the hardware. CONSTITUTION:A line signal LS is inputted to an FF6 and the output of the FF6 is inputted to an FF7. Logical gates 11, 12 detect that the values of the FFs 6, 7 are the same and an FF8 is operative accordingly. For example, suppose that the period of a clock signal CK is 2ms, when the signal LS within 2ms is changed, the content of the FFs 6, 7 is not the same and no signal is outputted from the gates 11, 12. Thus, even if a short pulse due to the chattering enters the signal LS, it is eliminated. Then, the number of dial pulses is counted by inputting an output of the FF8 to a counter 9. On the other hand, a processor 1 fetches the content of the FF8 and counters 9-1-9-4 by transmitting a specific address to an address bus 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a telephone subscriber circuit for counting dial pulses.

Conventionally, this type of subscriber circuit is as shown in FIG.
The program of the processing device 1 causes the line signal L to be output frequently.
It is known to identify and count dial pulses by monitoring S and detecting changes therein.

In other words, the on-footer and off-footer signals of the telephone line are
In order to directly read the line signal LS' reflected in "0#" and ""1#, respectively, by the program of the processing device 1, a specific address is transmitted from the processing device 1 onto the address bus 2, and it is transmitted by the decoder 3. When a match is detected, gate 4 is opened and data is sent to line signal L8'.
It is sent to the tapas 5 and read by the processing device 1.

However, in such conventional circuits, the dial pulses may be more than 20 pulses per second, so 8
Scanning had to be performed at a high frequency of about ms. Therefore, the load on the processing device is so heavy that dial pulses can actually be counted only during the dialing period after a call is made. In particular, in the past, when requesting various services for calling a third party during a call, or various services for encountering a third party during a call, the user had to rely on hooking operations. This hooking operation is performed by pressing the hook of the phone for about 1 second, but if it is shorter than this, it will be ignored, and if it is too long, it will be disconnected, and it will be a problem for the user. It became difficult to operate, and the various services that had been put in place became useless.

The object of the present invention is to be able to achieve the counting of dial pulses from an M4 phone without increasing the load on the entire processing device, thereby making it possible to count dials even during a call, such as during two conversations, and eliminating the need for picking operations that often result in operational errors. Instead, it provides a powerful telephone circuit that makes it possible to request various services by dialing a number.

In order to achieve such an object, the present invention is characterized in that a counter is provided in the subscriber circuit to count the changes in the 1/C and line signals, and the changes in the signals are counted by hardware. .

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 shows an embodiment of the telephone subscriber circuit according to the present invention, in which 6.7 is a flip-flop constituting a shift register, 8 is a flip-flop, 9 is a counter, and 10 is a flip-flop.
11 to 14 are logic gates, and 15 read/write signal lines. Other symbols correspond to the same symbols in FIG.

The line signal L S fl is inputted to a seven flip-flop 6 at the front stage of the shift register, and the output of the flip-flop 6 is inputted to a flip-flop 7 at the rear stage, and this shift register can be shifted by the rising edge signal of the clock CK.

Logic gates 11 and 12, flip-flops 6 and 7
It is detected that the values of n become the same, and accordingly, the flip-flop 8 is incremented by one.

For example, if the period of the tarok signal CK is 2ms, if there is a change in the line signal LS within 2ms,
The values of flip-flops 6 and 7 are not the same and are shifted, so no signal is output from gates 11 and 12. Therefore,
Even if a short pulse due to a chattering phenomenon enters the line signal LS, it can be completely eliminated, and thereby a signal that is prevented from malfunctioning can be reflected in the flip-flop 8.

By inputting the IPL power of the flip-flop 8 to a four-stage counter 9, it is possible to count the number of times the line signal goes off-hook, that is, the number of dial pulses.

On the other hand, the processing unit 1 operates the decoder 3 by sending a constant address to the address number 2, and
A signal is sent to the read 7 convolution signal line 15. If the signal line 15 indicates bladder evacuation, the output of the logic gate 13 opens the gates 10-1 to 10-5, and the flip-flops 8,
All contents of each stage 9-1 to 9-4 of the counter are taken into the processing device 1 through the data bus 5.

Furthermore, if the signal line 15 indicates writing, the contents of the counter 9 are cleared by the output of the logic gate 14 and 0.
is written.

According to the present invention described above, the processing device only needs to read the line signal at a slow cycle of about 100 ms or more, whereas conventionally the processing device had to read the line signal at a cycle of about 8 ms.
The load on the processing device can be greatly reduced, and service requests can be made by dialing even during a single call.

The number of stages of the counter depends on the reading cycle and is not necessarily 4.
No need for a pit. Even in the case of 20 pulses per second or more, at 100 m5 it is about 2 pulses, and in this case, at most 2 pulses.
Steps are fine.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional 710 subscriber circuit, and FIG. 2 is a block diagram of a subscriber circuit according to the present invention.

Claims (1)

[Claims] 1. A means for inputting a line signal sent from a telephone, a counting means for counting the pulses of the line signal, and the contents of the counting means at a predetermined period according to a command from a processing device. A subscriber circuit for a telephone set, comprising control means for reading and inputting the information to the processing device. 2. The input means comprises means for sampling all of the line signals at predetermined timings, and means for ignoring changes in the signal within the time intervals of the timings, as set forth in claim 1. telephone subscriber circuit.