JPH0537308Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a printing device that receives print data from a computer and prints.
The present invention relates to a printing device equipped with the above interface circuit.

(Prior art) Various host computers,
Alternatively, it is equipped with multiple interface circuits to enable connection with a personal computer.

In such a case, for example, what is normally installed is a Centronics-compliant standard interface circuit and an RS-232C standard serial interface circuit. The former has a higher data transfer rate than the latter but only has the ability to transfer data in one direction, while the latter has a slower data transfer rate than the former but has the ability to transfer data in both directions.

Furthermore, although both of the above interface circuits are installed, when using the interface circuit, for example, one of the interface circuits to be used is selected by a switch circuit corresponding to the other party's computer, and the unselected interface circuit is used as a switch circuit. The configuration was such that it could not be used until it was selected.

(Problem that the invention aims to solve) Therefore, even if multiple interface circuits are installed as in the example above, only one interface circuit is used, and the other interface circuits cannot be selected. The problem was that all you had to do was wait for it to be done.

Further, if an interface circuit is selected incorrectly and an interface circuit that does not correspond to the input data is selected, there is a problem that no printing is performed at all.

An object of the present invention is to provide a printing device that solves the above-mentioned problems.

(Means and operations for solving the problems) In order to solve the above problems, the system was constructed as shown in the functional block diagram shown in FIG.

It is equipped with a plurality of interface circuits 1 and 2 (hereinafter, for the sake of explanation, the plurality will be referred to as "2") to which signal data including print data is supplied from the outside, and a printing means 3 that performs printing in accordance with the print data. In the printing device 4, a first determining means 5 determines through which interface circuit 1 or 2 signal data is supplied first, and a circuit other than the interface circuit determined by the first determining means 5 is provided. It has stop means 6, 7 for substantially stopping the supply of signal data via the interface circuit.
Therefore, when signal data is first supplied via the interface circuit 1, this is determined by the first determining means 5, and the stopping means 7 stops the supply of signal data from the interface circuit 2. is substantially stopped, input signal data is supplied via the interface circuit 1, the substantially open stopping means 6, and the first determining means 5, and the printing means 3 prints in accordance with the print data. will be done. Furthermore, it is provided with a discriminating means 8 for discriminating that the input signal data is page break command data, and a canceling means (not shown) for canceling the stoppage of signal data supply by the stopping means 6 and 7 when the page break command is executed. , when the input signal data supplied via the first determining means 5 is page break command data, the second determining means 8 determines that fact, and after the page is broken by the page break command data, the canceling means causes the stopping means to The suspension of supply of signal data from 7 is substantially canceled. As a result, the stopping means 6
In both cases 7 and 7, the output of signal data is not substantially stopped. In this state, signal data will be supplied to one of the interface circuits again. Note that although the above description has been made by taking as an example the case in which signal data is supplied to the interface circuit 1 first, the same applies to the case in which signal data is supplied to the interface circuit 2 first.

Therefore, there is no possibility of selecting the wrong interface circuit.

(Example) The present invention will be explained below with reference to examples.

FIG. 2 shows a configuration diagram of equipment using an embodiment of the present invention, and FIG. 3 is a block diagram showing the configuration of the first embodiment of the present invention.

Signal data from an external device 16 consisting of a microcomputer is supplied to the printing device 15 via a Centronics-compliant interface circuit, and input data from an external device 17 is supplied via an RS-232C standard serial interface circuit. Ru.

The printing device 15 includes a Centronics-compliant parallel interface circuit 18 that receives signal data from an external device 16, an RS-232C standard serial interface circuit 19 that receives signal data from an external device 17, and an interface circuit 18 or A CPU 20 that receives and processes signal data supplied through the ROM 19, and a character generator ROM.
(hereinafter referred to as CGROM) 21, working area 22A
RAM 2 with external character registration area 22B
2. Program ROM2 that stores programs
3. Deep switch 24 for setting the startup mode when the power is turned on, interface circuit 1
8 or 19 to which the signal data is supplied.
Interrupt controller 25 transmits to CPU 20
and a printing section 26, and is configured to perform printing in accordance with print data supplied via interface circuits 18 and 19. That is, the printing device 15 has an interface circuit 1.
8, 19, receiving interface circuit 1
It is configured to select 8 or 19.

The operation of the printing device 15 in one embodiment of the present invention constructed as described above will be explained with reference to FIG. 4 along with the program stored in the ROM 23.

When power is supplied to the printing device 15, initial settings including initial settings of the interface circuits 18 and 19 are performed (step a), and the external device 1
It waits for signal data to be input from 6 and 17. The initial settings in step a also include setting the start-up mode using the dip switch 24. In this state, interface circuit 1
8 and 19 are both ready to receive signal data.

Next, signal data is supplied via either interface circuit 18 or 19. As a result of this supply, an interrupt signal is supplied to the CPU 20 from the interface circuit that previously received the signal data via the interrupt controller 25 (step b). Upon receiving the interrupt signal, the CPU 20 determines which interface circuit the interrupt signal is from (step c), and masks the interrupt signal from the interface circuit that did not generate the interrupt signal (step d). In this example, step c
At step d1, it is determined whether or not signal data is supplied from the interface circuit 18, and when an interrupt signal is supplied from the interface circuit 18, interrupts from the interface circuit 19 are prohibited (step _d1 ), and the interface circuit If it is not supplied from interface circuit 18,
Interrupts from are disabled (step _d2 ). As a result of step d being executed, from then on until step k described later, signal data can only be input from the interface circuit whose interrupt signal is not masked, and the signal data can only be input from the external device that originally supplied the data. Data from will be accepted.

Next, signal data is input from an interface circuit in which interrupts are not inhibited (step e), and it is determined whether the input signal data is command data, such as page feed command data, font switching data, etc. (step f). If the input signal data is not command data, i.e., if it is print data, normal print processing is performed (steps g, e). If it is determined to be command data, it is determined whether the command data is page feed command data (step h), and if it is command data other than page feed command data, processing corresponding to the command is performed (steps i, e). If it is determined to be page feed command data, a page feed is executed (step j), and then the interrupt inhibition is released (step k), and then step b is executed. Therefore, it is possible to receive signal data from the interface circuit that was masked in step d.

In this example, after a page break, signal data from the interface circuits 18 and 19 is awaited, and signal data from the interface circuit to which signal data was supplied earlier is accepted until the next page break. Become.

Next, a second embodiment will be explained with reference to FIG.

The block diagram showing the configuration of the second embodiment is the same as that in FIG.

In the second embodiment, steps a to d are the same as in the first embodiment, and their explanation will be omitted.

Following step _d1 , it is determined whether the signal data is page break command data (step _m1 ).
If the signal data is not determined to be page break command data in step _m1 , the signal data is stored in a buffer area (I) corresponding to the interface circuit 18 and provided in the working area 22A of the RAM 22 (step n ₁ ), it is determined whether there is any remaining storage capacity in the buffer area (I) (hereinafter referred to as whether the buffer area (I) is full) (step p ₁ ).

When it is determined in step _m1 that the signal data is page break command data, printing is performed following step _m1 in accordance with the print data in the signal data stored in the buffer area (I). q ₁ ), buffer memory (I)
is initialized (step r ₁ ). When the buffer memory (I) is initialized, the interrupt signal is unmasked (step s ₁ ), and step b is executed again. Therefore, when page break command data arrives, printing is performed along with the print data currently stored in the buffer area (I), and interrupt signals from the masked interface circuit can also be accepted. , and waits for the arrival of signal data from the interface circuits 18 and 19.

When it is determined in step _p1 that the buffer area (I) is full, steps _q1 , _r1 , _s1 , and b are sequentially executed following step _p1 . Therefore, in this case, after printing is performed in accordance with the print data in the signal data fully stored in the buffer area (I), the buffer area (I) is placed in a state of waiting for the arrival of signal data from the interface circuits 18 and 19. Ru.

When it is determined in step _p1 that the buffer area (I) is not full, steps _s1 and b are sequentially executed following step _p1 . Therefore, in this case, after the incoming signal data is stored in the buffer memory (I), it is put into a state of waiting for the incoming signal data from the interface circuits 18 and 19. This state is repeated until page break command data arrives or the buffer memory (I) becomes full.

Note that when signal data is first supplied to the interface circuit 19 instead of the interface circuit 18, that is, when step d2 is executed, step _d2 is followed by step _d2 in the same way as above.
m ₂ , n ₂ , p ₂ to s ₂ will be executed. In this case, the buffer area () corresponds to the interface circuit 19 and is provided within the working area 22A of the RAM 22. The operation in this case is the same as above, and the explanation will be omitted.

Furthermore, in the second embodiment described above, steps d ₁ , d ₂ , s ₁ and s ₂ may be omitted.

In the embodiment described above, the user of the printing device does not have to change the interface circuits 18 and 19 at all by means of switch circuits. moreover,
In the above, the interface circuit 18 is a Centronics compliant parallel interface circuit, and the interface circuit 19 is an RS-232C standard serial interface circuit.
Although the case of an interface circuit is shown, there is no need to be limited to this, and any type of interface circuit can be used. Furthermore, a plurality of interface circuits of the same type may be used.

(Effect of the invention) As explained above, according to the invention, a first determining means is provided for determining which interface among a plurality of interface circuits is supplied with signal data first, and the first determining means is provided. Since the supply of signal data from the interface circuits other than the interface circuit determined by the means has been substantially stopped by the stopping means, the interface circuit to which the signal data was supplied first is selected, and the manual There is no need to switch between the interface circuits and the interface circuits that should be selected by mistake.

Further, the second determining means determines that the page break command data has been supplied, and at least after the page break by the determined page break command data, the stopping of the supply of signal data by the stopping means is released. When a page is created, all the multiple interface circuits are again in a state of waiting for the arrival of signal data, and a specific interface circuit is not always selected, and the interface circuit to which the signal data was supplied first is This has the effect of selecting the ace circuit.

Furthermore, when a page break is executed using the page break command data, the stoppage of the signal data supply by the stop means is released, so that the print data that is sent next can be printed, and the data that is sent immediately after the page break data can be printed. This also has the effect that the waiting time until the incoming print data is printed is reduced, and the time required to print all the incoming print data is shortened.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram showing the configuration of the present invention.
FIG. 2 is an equipment configuration diagram using an embodiment of the present invention. FIG. 3 is a block diagram showing the configuration of the first embodiment of the present invention. FIG. 4 is a flowchart for explaining the operation of the first embodiment of the present invention. FIG. 5 is a flowchart for explaining the operation of the second embodiment of the present invention. 1, 2, 18 and 19...interface circuit, 3...printing means, 4 and 15...printing device, 5...first discrimination means, 6 and 7...stopping means, 8...second discrimination means .

Claims (1)

[Claims for Utility Model Registration] A plurality of interface circuits that receive signal data including print data supplied from an external device;
In a printing device including a printing means for printing in accordance with the print data supplied via the interface circuit, it is determined through which interface circuit the signal data is supplied first. a first determining means for determining, a stopping means for substantially stopping the supply of signal data from an interface other than the interface circuit determined by the first determining means, and an interface circuit determined by the first determining means. a second determining means for determining whether the signal data supplied from the circuit is page break command data; and supplying the signal data by the stopping means after the page break command determined by the second determining means is executed. 1. A printing device comprising: a release means for substantially releasing the stoppage.