JPH0222928A - Input circuit for processor - Google Patents

Abstract

PURPOSE:To improve the activity efficiency of an A/D input port by enabling plural kinds of signals to be inputted from one A/D input port by using an existing output port. CONSTITUTION:When a digital signal is outputted from one arbitrary port of plural output ports 101 with a prescribed voltage selectively, the voltage of a digital signal is voltage-divided by a voltage division means 106 equipped with a first resistor 104 and a second resistor 105 having prescribed resistance values corresponding to the output ports 101, and is inputted to the A/D input port 102 as an analog signal. Therefore, it is possible to input the plural kinds of signals from one A/D input port 102 to a processor 103 by using the existing output port 101. In such a way, the activity efficiency of the A/D input port 102 can be improved.

Description

Detailed Description of the Invention (a) Industrial Application Field Does this invention output digital signals? The present invention relates to a processor input circuit having a JIl output port and an A/D input port capable of inputting an analog signal.

(b) Prior Art Generally, a processor, mainly called a microprocessor, is provided with an input port and an output port.

For example, in a processor used to control the temperature of an air conditioner, etc., there is an output port that outputs a digital signal that takes a value of either 0 volts or 5 volts, and an 8-bit signal that outputs a digital signal that takes a value of either 0 volts or 5 volts. In A/D conversion, depending on the resolution of A/D conversion, the hex value is 00~
Give the voltage changed in 256 ways from FF (0 to 255 in decimal value) as an analog signal, and
A that can be accepted as 6 types of digital signals
/D input port is turned off.

Therefore, in the input circuit of this type of processor, especially in a circuit that does not use a dedicated external input circuit or a dedicated output port, and only has a resistor, the processor lO's A/D person Kaika port P
When inputting an analog signal to +n, the first resistor R++-Rn+ and the second resistor R are connected to each A/D port P1 to Pn.
The voltage is divided and input using a voltage dividing resistor consisting of 1t-Rn2.

That is, a signal as data S is inputted to the A/D input port P by the voltage dividing resistor from the first resistor R1 and the second resistor R1, and then the A/D input port P is input to the A/D input port P. Similarly, signals from data S to data Sn are input to the D input port Pn, and the input data S+-Sn are transferred to data memories a and b for constants of the processor IO.

The information is transferred to C1, . . . , and X for storage.

(c) Problems to be Solved by the Invention However, in the conventional input circuit of such a processor IO, one A/D input port can only give a signal as one type of data. In order to provide multiple different types of signals to the processor IO, a dedicated A/D input port is required for each signal to be provided, and as the number of signal types increases, the number of A/D input ports becomes necessary and the system It becomes a design obstacle.

The present invention has been made in consideration of such circumstances, and provides an input circuit for a processor that can input multiple types of signals to one A/D input port by using existing output ports. It is something.

(d) Means to solve the problem FIG. 1 is a block diagram showing the configuration of the present invention.

In this figure, 101 is a plurality of output ports that selectively output digital signals at a predetermined voltage from any one port, and 102 is an 'A/
A D input port, 103 is a processor equipped with an output port 101 and an A/D input port 102, and when an analog signal is input from the A/D input port 102, the signal is sequentially converted into a digital signal and taken in, and 104 is a plurality of output ports. 101 and a single A/D input port 102, a plurality of first resistors 105 for voltage division having different predetermined resistance values;
106 includes a second resistor for voltage division connected to the A/D connector port 102, a first resistor 104 and a second resistor 105, and is selectively output from any one of the plurality of output ports 101. This is a voltage dividing means that divides the voltage of a digital signal according to its output port and inputs it to the A/D input port as a lO2 analog signal.

Note that the output port 101 in the present invention does not refer to an output port specifically reserved for inputting the A/D input port 102, but refers to an existing output port for outputting various signals from the processor +03. do.

Further, the digital signal from this output port 101 is output as a binary voltage of 0 or 5 volts depending on the presence or absence of a certain voltage set in advance by the processor 103.

(E) Effect In FIG. 1, when a digital signal is selectively outputted from any one of the plurality of output ports 101 at a predetermined voltage, the voltage of the digital signal is changed to a predetermined voltage corresponding to that output port. A voltage is divided by a voltage dividing means 106 comprising a first resistor 104 having a resistance value and a second resistor 105.
/D input port 102 is input as an analog signal.

Therefore, without using a special dedicated output port, by using the existing output port 101, it is possible to input a plurality of types of signals to the processor 103 between one A/D input port and the A/D input port. The efficiency for port 102 is greatly improved.

(f) Examples Hereinafter, the present invention will be described in detail based on examples shown in the drawings. Note that this invention is not limited to this.

FIG. 2 is an input circuit diagram showing an embodiment in which the present invention is applied to an input circuit of a processor of an air conditioner.

In this figure, 0. ~On is a plurality of output ports that are provided in the processor l and output digital signals, and when the air conditioner is powered on, after completing the initial settings of each part inside the processor l, various signals for air conditioning, e.g. , the fan rotation speed for setting the air volume, or the current temperature setting.

In addition, these multiple output ports 0. ~On is a predetermined voltage from any one port, for example, 5 volts, and 0
It outputs a digital signal representing 0 or l depending on whether it is volt or 5 volt.

P is a single A/D input port for inputting analog signals.

D1~Dn are diodes for preventing reverse current flow, RIf~R
n, is the !th part for partial pressure that connects the output port ○I~On and the A/D input port P. is a resistor, and the first resistor R11~
Rn+ has different predetermined resistance values in order to set the input voltage V, ~Vn for inputting from each output port 01~On to the A/D input port P1 to each output port O1~On@. are doing.

R, is a second voltage dividing resistor connected in parallel to the A/D input port Pl, and the output ports 01 to On are The voltage of the digital signal selectively output from any one port of is divided according to each output port 01 to On to set the input voltages V1 to Vn, and these are converted into analog signals to the A/D input port. It is designed to be input to P.

Therefore, the analog signal inputted by each input voltage V,=Vn is sequentially converted into data S,=Sn as a digital signal inside the processor l, and is stored in the constant data memory λ,b of the processor l.

C1..., X are transferred and stored, respectively.

LED, ~LEDn are light emitting diodes, RQ, ~RQn
is a resistor, Q, ~Qn is a light emitting diode LED, ~LED
E is a power supply terminal for supplying power to a light emitting diode LED (=LEDn).

Each output port 01 to 0□ was originally set to light each light emitting diode LED, to LEDn after the initial setting as described above, and each output port 0
,=On, when a signal is output from one port, the LED drive transistor corresponding to that output port performs a switching action, and the light emitting diode LED, ~L
One of the EDn lights up.

The operation in such a configuration will be explained based on the flowchart shown in FIG.

First, when the air conditioner is powered on, after completing the initial settings of each part inside the processor 1 (step 20, only the output of IL output port 01 is set to high level (H), and the output of output ports O7 to On of the pond is set to low level). When the level is set to (L) (step 202), the voltage V divided by the resistor R+ and the resistor R2 is applied to the A/D input port P through the diode D.
, is applied.

After a waiting time that takes into account the transient characteristics until the voltage Vl stabilizes (step 203), the data SI is converted to A/D (step 204) and stored in the constant data memory a.
(step 205).

Next, output port 0. When only the output of is set to high level and the outputs of other output ports 01 and O1 to On are set to low level (step 206), resistors R7 and R8 are connected to A/D input port P through diode D.
A voltage Vt divided by is applied, and after a waiting time that takes into account transient characteristics (step 207), it is converted to A/D (step 208), and the data S is transferred to data memory b for constants. (Step 209).

Similarly, the output of output port 03 is at high level,
Output port 0. ．． 0. ．． 0. ~○n is at low level, A/D input port P1 has resistor R31 and resistor R1.
The operation is performed as shown in steps 210 to 213), in which a voltage (2) is applied by the voltage division of (210 to 213), and the A/D converted data S3 is transferred to the constant data memory C (steps 210 to 213).
By repeating the process several times, n types of voltages V1 to Vn divided by the resistors R11 to Rn+ and the resistor R1 are applied, and the corresponding n A/D conversion data Sn are converted to data for n constants. Step 21: Transfer data S, =Sn to memories a, b, c, . . . , X respectively and store them.
4 to 217), move to the main routine and save the data S.
This means that l-S n is used.

Note that the output ports O3 to On are light emitting diodes LED.
This invention is unique in that it is a port for turning on or off the l-LEDn, and the input to the A/D input port P1 is just using it, and it is not provided exclusively for this data reading work. It has the characteristics of

In this way, multiple types of signals can be input to the processor l from one A/D input port P by using existing output ports without using a special dedicated output port. The utilization efficiency of the D input port P1 can be greatly improved.

(G) Effects of the Invention According to this invention, it is possible to input multiple types of signals to a processor from one A/D input port by using existing output ports without providing a dedicated output port. Therefore, the usage efficiency of the A/D input port is greatly improved.

Furthermore, since there is no restriction on the number of input ports, the degree of freedom in system design is greatly increased and system design becomes easier.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of the present invention, Fig. 2 is an input circuit diagram showing an embodiment in which the invention is applied to the input circuit of a processor of an air conditioner, and Fig. 3 shows the operation of the embodiment. The flowchart, FIG. 4, is an input circuit diagram of a conventional processor. 1...Processor, O1~On...Output port, Pl...A/D input port, R11-RnI...First resistor for voltage division, R2・
...Second resistor for voltage division. Figure 1 2rl! 1 Figure Figure

Claims (1)

[Claims] 1. Equipped with multiple output ports that selectively output digital signals at a predetermined voltage from any one port and an A/D input port that can input analog signals, and outputs analog signals from the A/D input port. a processor that sequentially converts the signal into a digital signal and takes it in when the signal is input, and a plurality of first voltage divider circuits that connect the plurality of output ports and the single A/D input port and have different predetermined resistance values. It is equipped with a resistor and a second voltage dividing resistor connected in parallel to the A/D input port, and divides the voltage of a digital signal selectively output from any one of the plurality of output ports according to the output port. An input circuit for a processor comprising voltage dividing means for inputting an analog signal to a pressure A/D input port.