JPH02280598A - Integrated circuit for remote controller - Google Patents

Abstract

PURPOSE:To allow the circuit to cope with lots of remote controllers with only the revision of modulo by switching two modulo value counters, using a comparator so as to compare the count values thereby generating a remote control carrier signal with a broad operating frequency with lots of duty ratios. CONSTITUTION:A count value of a binary counter 10 is inputted to a comparator 40. A value is set to a low period modulo value register 20 and a high period modulo value register 20 from other control part of an integrated circuit respectively. The two setting values are switched by a comparison switching circuit 60 comprising a binary F/F and a switch 61 and either of them is other input to the comparator 40. A coincidence output signal of the comparator 40 is a reset signal of the counter 10 and also a clock for a binary F/F 70 (flip-flop) of the circuit 60. An output of the F/F 70 switches the registers 20 and 30. Moreover, the output of the F/F 70 is an input to a carrier output section 80 to modulate a code data being a digital signal of other input and outputs the result to an external device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an integrated circuit for remote control, and more particularly to an integrated circuit for remote control of electronic equipment (hereinafter abbreviated as remote control) using infrared rays or the like.

[Conventional technology]

Traditionally, remote controls have been used as accessories for various devices made by various electronics manufacturers, so the design of the remote control has also been determined by each company.
In particular, the output code format and carrier frequency differ depending on the manufacturer.

Regarding the format, it is possible to change the format using software control even in conventional integrated circuits for remote controls, but it is difficult to change the carrier frequency and duty ratio with integrated circuits for remote controls that have a built-in variable frequency divider. Therefore, it was possible to use the same integrated circuit only from manufacturers with similar carrier frequencies.

[Problem to be solved by the invention]

Generally, remote controllers often use a carrier frequency in the order of 30 KHz, but the frequency used and the carrier duty ratio vary depending on the manufacturer. These are designed in order to avoid being affected by the remote controls of each company, as well as taking into account the battery life of the remote control, the characteristics of the light receiving side, etc. Furthermore, in order to prevent disturbances, carriers in the 500KHz range have been used, but conventionally it has been difficult to meet these wide requirements with a single integrated circuit, and in order to meet this requirement, another Integrated circuits were needed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a remote control integrated circuit that can be used in a wide range of frequencies and duty ratios.

[Means to solve the problem]

The integrated circuit of the present invention includes means for storing first and second set values, a counter for counting a reference frequency, and means for selectively outputting the first and second set values according to the level of a selection signal. means for comparing the selected set value and the counter value and outputting a match signal when they match; means for resetting the counter based on the match signal; and means for adjusting the level of the selection signal based on the match signal. , and the selection signal is used as a remote control carrier signal.

〔Example〕 The present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram illustrating a 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 each 6-bit registers whose values are set by other control sections of the integrated circuit. These two set values are determined by a comparison switching circuit 60 consisting of a binary F/F and a switch 61.
Either one becomes the other input to the comparator 40. The coincidence output signal of the comparator 40 becomes a reset signal of the binary counter 10, and at the same time, the binary F/F 70 (Fri, B-Flop) of the comparison switching circuit 60
The low interval modulo value register 20 and the high interval modulo value register 30 are switched by the output of the binary F/F 70, which is in the range of black and red. Also binary F
The output of /F70 becomes the input of the carrier output section 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 divider 50
This is the output of the reference frequency divided by 1/2. The reference frequency is ANDed with the divider 50 and sent to the comparator 40.
This is used as the timing for comparison.

Next, to explain the operation of each part, first, when the binary F/F 70 is reset by system reset, the output signal Q of the binary F/F 70 is O, and using it as a selection signal, the comparison switching circuit 60 is in the low range. A comparator 40 selects the data of 2006 bits of the modulo value register and compares it with the count value from the binary counter 10. When the count value of the binary counter 10 becomes equal to the set value of the low interval modulo value register 20, the comparator 4
A match signal is generated from 0, and the binary counter 10 is reset, and the output of the binary F/F 70 becomes 1 at the same time. Thereafter, the comparator 40 compares the set value of the high interval modulo value register 30 and the count value of the binary counter. This timing is shown in Figure 2, which shows the operation of each part when the low interval modulo value register 20 is set to 3 and the high interval modulo value register 30 is set to 2. The output is used as a remote control carrier signal, and the code data is modulated with this signal and output to the output terminal. In this embodiment, the fundamental frequency is f, the low interval modulo value is m, and the high interval modulo value is n. If set, the output carrier frequency will be.

For example, if f=4.19MHz, the maximum value is m=1n=
1, an output of about 1.05 MHz can be obtained. Also, m=2
When @ n = 2 @, the output carrier frequency is approximately 1.6 KHz when f = 4.19 MHz, which shows that the frequency can be set over a wide range. Also, the combinations that can be set including duty changes are 6 bits for m and 6 bits for n, so 2'X2'=2''=409
Eight choices are possible.

FIG. 3 is a block diagram for explaining a second embodiment of the present invention. The difference from the first embodiment is that only the modulo register 25 is provided, and the comparison switching circuit 60 uses comparison switching to determine whether the value of the modulo register 25 is directly compared or compared with a value shifted to the right one bit at a time. In this example, the duty ratio of the high section is fixed to be approximately twice that of the low section of the first embodiment. In other words, in a binary counter, shifting to the right means dividing by 2, and the high interval is always half the low interval. However, 1 bit that is lost when shifting to the right becomes an error.

Although this example does not allow small changes in the duty ratio, it shows that the present invention can be applied even when the application set is limited to a certain extent.

〔Effect of the invention〕

As explained above, the present invention switches two modulo value counters and compares the count value with a comparator, thereby converting, for example, a 6-bit modulo value register into two.
By using one, 4096 different frequency-divided waveforms can be selected. Therefore, it is possible to generate remote control carrier signals with a wide range of usable frequencies and many duty ratios, and the integrated circuit for remote control according to the present invention can be used with many remote control devices by simply changing the modulo value. effective.

[Brief explanation of drawings]

FIG. 1 is a block diagram illustrating a first embodiment of the present invention;
FIG. 2 is a timing diagram for explaining the first embodiment of the present invention, and FIG. 3 is a block diagram for explaining the second embodiment of the present invention. lO...Binary counter, 20...
Low interval modulo value register, 25... Modulo register, 30... High interval modulo value register, 4o... Comparator, 50...
・Frequency divider, 60... Comparison switching circuit, 70...
...Baina! jF/F, 80/old...carrier output section. Agent Patent Attorney Otoshi Uchihara tl Value Assault Mature Selection Bemo et al. 9 Roasted Memories ~ δV 1st Co.

Claims (1)

[Claims] a counter for counting a reference frequency; means for selectively outputting first and second set values in accordance with the level of a selection signal; comparing the selected set value and the value of the counter, and when the two match; The method further comprises means for outputting a coincidence signal, means for resetting the counter using the coincidence signal, and means for changing the level of the selection signal using the coincidence signal, and using the selection signal as a remote control carrier signal. Features integrated circuit for remote control.