JPH0744731B2 - Integrated circuit for remote control - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an integrated circuit for remote control, and more particularly to an integrated circuit for remote control (hereinafter abbreviated as remote control) of electronic equipment using infrared rays or the like.

[Conventional technology]

Conventionally, the remote control is used as an accessory of each equipment of each electric manufacturer, so the design of the remote control is also different for each company,
In particular, the output code format and carrier frequency differ depending on the manufacturer. The format can be changed by software control even in the conventional remote control integrated circuit, but it was difficult to change the carrier frequency and duty ratio with the normal remote control integrated circuit with a built-in variable frequency divider. Therefore, only the manufacturers with similar carrier frequencies can handle the same integrated circuit.

[Problems to be Solved by the Invention]

In general, remote controllers often use carrier frequencies in the range of thirty and several KHz, but the manufacturer's operating frequency and carrier duty ratio differ. These are designed in order to avoid the influence of the remote control of each company and the battery life of the remote control and the characteristics of the light receiving side. Further, carriers of 500 KHz level have been used to prevent disturbance, but conventionally, it has been difficult to satisfy these wide requirements in one integrated circuit, and it is difficult to meet this demand. An integrated circuit was needed.

An object of the present invention is to provide an integrated circuit for a remote controller which can handle a wide range of operating frequencies and duty ratios.

[Means for Solving the Problems]

The integrated circuit of the present invention comprises means for storing the first and second set values, a counter for counting the reference frequency, and means for selectively outputting the first and second set values according to the level of the selection signal. A means for comparing the selected set value and the counter value and outputting a coincidence signal when they coincide with each other; a means for resetting the counter by the coincidence signal; and a level of the selection signal by the coincidence signal. And a means for changing the selection signal, and the selection signal is used as a remote control carrier signal.

〔Example〕

 The present invention will be described with reference to the drawings.

FIG. 1 is a block diagram for explaining the first embodiment of the present invention. The binary counter 10 is a six-stage counter and its count value is input to the comparator 40. The low interval modulo value register 20 and the high interval modulo value register 30 are 6-bit registers, and their values are set by other control parts of the integrated circuit. The setting value for these two is binary F /
It is switched by the comparison switching circuit 60 composed of F and the switch 61, and one of them becomes the other input to the comparator 40. The coincidence output signal of the comparator 40 becomes the reset signal of the binary counter 10, and at the same time, the binary F /
It is the clock for F70 (flip-flop). Low interval modulo value register 2 by output of binary F / F70
Switching between 0 and the high section modulo value register 30 is performed. The output of the binary F / F 70 becomes the input of the carrier output unit 80, which modulates the code data of the digital signal, which is the other input, and outputs it to the outside. The input of the binary counter 10 is the output of the frequency divider 50, which divides the reference frequency by 1/2. The reference frequency is ANDed with the frequency divider 50 and the comparator 40
It is used as a timing for entering and comparing.

Next, the operation of each part will be described. First, when the binary F / F70 is reset by the system reset, the output signal Q of the binary F / F70 is 0, and the comparison switching circuit 60 uses it as a selection signal for the low interval modulo value. register
The 20-bit 6-bit data is selected and compared with the count value from the binary counter 10 by the comparator 40. When the count value of the binary counter 10 becomes equal to the set value of the low interval modulo value register 20, a match signal is generated from the comparator 40 with the reference frequency as timing, and the binary counter 10 is reset and at the same time the output of the binary F / F 70 is output. Becomes 1. After that, the comparator 40 compares the set value of the high interval modulo value register 30 with the count value of the binary counter. This timing is shown in FIG. 2, where 3 is stored in the low interval modulo value register 20,
The operation of each unit when 2 is set in the high section modulo value register 30 is shown. In this embodiment, the Q output of the binary F / F 70 is used as the remote control carrier signal, and the code data is modulated by this signal and output to the output terminal. In this embodiment, assuming that the fundamental frequency is f, the low interval modulo value is m, and the high interval modulo value is n, the output carrier frequency is Becomes

For example, when f = 4.19 MHz, the maximum value is m = 1 and n = 1, and an output of about 1.05 MHz is obtained. Also, m = 2 ⁶ n = 2 output carrier frequency as ⁶ to the f = 4.19MHz about 1.6KH
It becomes z, and it can be seen that a wide range of frequencies can be set. The settable combinations, including the duty change 6 bits as m, because 6 bits as n 2 ⁶
× 2 ⁶ = 2 ¹² = 4096 ways can be selected.

FIG. 3 is a block diagram for explaining the second embodiment of the present invention. The difference from the first embodiment is that it has only the modulo register 25 and whether it is directly compared with the value of the modulo register 25 by comparison switching in the comparison switching circuit 60 or the value shifted right by one bit. Is the point that is switched. In this example, the duty ratio of the high section to the low section of the first embodiment is fixed so as to be approximately doubled.
That is, in the binary counter, right shift is divided by 2, and the high section is always half of the low section. However, an error occurs when one bit is missed when shifting to the right. This example shows that the present invention can be applied even when the application set is limited to some extent, although a small change in the duty ratio cannot be made.

〔The invention's effect〕

As described above, according to the present invention, by switching between two modulo value counters and comparing the count value with a comparator, for example, a 6-bit modulo value register is set to 2 bits.
By using one of them, it is possible to select 4096 kinds of divided waveforms. Therefore, it becomes possible to generate remote control carrier signals having a wide range of frequencies and many duty ratios, and the remote control integrated circuit of the present invention can cope with many remote control devices only by changing the modulo value. effective.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a first embodiment of the present invention.
FIG. 2 is a timing chart for explaining the first embodiment of the present invention. FIG. 3 is a block diagram for explaining the second embodiment of the present invention. 10 …… Binary counter, 20 …… Low section modulo value register, 25 …… Modulo register, 30 …… High section modulo value register, 40 …… Comparator, 50 …… divider,
60 …… Comparison switching circuit, 70 …… Binary F / F, 80 …… Carrier output section.

Claims (1)

[Claims] 1. A counter for counting a reference frequency, a means for selectively outputting first and second setting values according to the level of a selection signal, and a comparison between the selected setting value and the counter value. The remote control carrier further comprises means for outputting a coincidence signal when both coincide with each other, means for resetting the counter by the coincidence signal, and means for changing the level of the selection signal by the coincidence signal. An integrated circuit for remote control, which is used as a signal.