JP2803552B2 - Data receiving device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data receiving device used for a printer or the like.

[0002]

2. Description of the Related Art Generally, in a data receiving apparatus used in a printer or the like, reception processing is performed by interruption in order to operate image and character data reception processing and other control processing asynchronously. Store in the receive buffer.

However, the normal interrupt processing has a problem that it takes a long time to save and restore registers, so that the transfer speed cannot be increased, and it takes a very long time to receive a large amount of images or character data to be printed. .

Conventionally, as a method for solving this kind of problem, a data receiving apparatus in which hardware such as a direct memory access circuit (hereinafter, referred to as a DMA circuit) is added, for example, as disclosed in 63-29111
As described in Japanese Patent Application Laid-Open No. 4 (1999) -2004, there is a device that performs special processing by software.

[0005] A data receiving apparatus using a DMA circuit is a known technique and is widely used, and thus will not be described in detail.

On the other hand, in the data receiving method described in Japanese Patent Application Laid-Open No. 63-291114, data is received in an interrupt routine of a CPU, and a large number of data are received at one time in this interrupt routine in accordance with the data transfer speed. This solves the above problem.

[0007]

However, the above-mentioned conventional data receiving apparatus has the following problems.

In a data receiving apparatus to which a DMA circuit is added, the cost of a hardware circuit increases.

On the other hand, in the data receiving method described in Japanese Patent Application Laid-Open No. 63-291114, the time for performing the data reception interrupt processing is limited due to other interrupt processing, and there is a possibility that sufficient reception speed cannot be expected. is there.

The present invention has been made in view of the above problems, and has as its object to realize a high-speed data receiving apparatus without adding hardware such as a DMA circuit.

[0011]

In order to achieve the above object, the present invention provides a CPU built in a data receiving apparatus main body.
And a data receiving circuit for receiving data transmitted from the external terminal device, wherein the data receiving circuit detects the reception of the transmitted data from the external terminal device and generates an interrupt to the CPU. Data reception detection means, reception data storage means for receiving the interrupt, acquiring the transmission data from the data reception circuit and storing the transmission data in the reception buffer, and analyzing the reception data stored in the reception buffer. Receiving data analyzing means for acquiring valid data or control commands for the data receiving device; data string processing means for processing a data string whose data amount is specified by the data or control commands; and Reception monitoring means for monitoring reception of the data sequence from the terminal device. That it is constituted.

[0012]

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

FIG. 1 is a block diagram showing the configuration of a printer according to one embodiment of the present invention.

As shown in FIG. 1, the printer 1 includes a data receiving circuit 3, an interrupt controller 4, an interrupt processing unit 5, a main processing unit 6, and an image memory 7.

The data receiving circuit 3 detects the transmission of data from the external terminal device 2 and requests the interrupt controller 4 to generate a reception interrupt 80 to the interrupt processing unit 5.

When the interrupt processing unit 5 receives the reception interrupt 80, the reception buffer control unit 51 acquires the reception data A from the data reception circuit 3, sends a reception completion signal 81 to the external terminal device 2, and A is stored in the ring-shaped reception buffer 52.

The reception data analysis unit 61 includes a reception buffer 5
2 is obtained and analyzed, and if it is determined that this is valid data or a control command for the printer, processing corresponding to the received data A 'is performed. At this time, the analyzed received data A ′ is
If the control command is a control command accompanied by (for example, character data or image data) and the amount of the data string B can be specified from the control command, a function of issuing an instruction 81 to prohibit the reception interrupt 80 to the interrupt controller 4; The function of issuing the processing request command 82 for the specified data string B to the processing section 62 and the function of issuing the reception permission 80 generation enable command 83 to the interrupt controller 4 after the data string processing section 62 is completed. Have. In the present invention, if the data string B continues after the interruption is prohibited, the data string B is directly taken into the image memory 7 without passing through the reception buffer 52.

The data string processing section 62 acquires the data string B 'stored in the reception buffer 52 from the data string B after the interruption is inhibited, performs appropriate processing, and transfers the data string to the image memory 7. At this time, when all of the data strings B whose amount has been specified cannot be obtained from the reception buffer 52, a function of issuing a reception monitoring command 84 for the remaining data strings B ″ to the reception monitoring unit 63 is provided. , A function of issuing a reception monitoring cancellation command 85 to the reception monitoring unit 63 after the processing of the data string B ″ is completed.

The reception monitoring unit 63 receives the reception monitoring command 84 from the data sequence processing unit 62 and monitors the data receiving circuit 3. The data receiving circuit 3 receives the remaining data sequence B ″ received from the external terminal device 2. It has a function of acquiring and delivering the acquired data to the data string processing unit 62. The remaining delivered data B ''
Is transferred to the image memory 7.

Next, the operation of the data receiving apparatus in the printer according to the present embodiment will be described with reference to FIGS. 1, 2 and 3. In a normal reception operation, when the data reception circuit 3 receives the reception data A from the external terminal device 2, a reception interrupt 80 is generated from the interrupt controller 4.

When the interrupt processing section 5 receives the reception interrupt 80, the process proceeds to step 100.

In the reception amount check in step 100, the free space of the reception buffer 52 is checked, and if there is free space, the process proceeds to step 101; otherwise, the process ends.

In storing the received data in step 101, the received data A is written to the address of the receive buffer 52 indicated by the write pointer, and the process proceeds to step 102.

In the update of the write pointer in step 102, the value obtained by incrementing the current write pointer by 1 is divided by the size of the reception buffer 52, and the remainder is entered in the write pointer, thus ending the processing.

Next, in FIG. 3, in the reception buffer check in step 200, it is checked whether or not data is stored in the reception buffer 52. If there is received data A 'already stored in the reception buffer 52, the process proceeds to step 201.

In the received data analysis process in step 201, the received data A 'is analyzed. If it is determined that the data sequence B is followed by the data sequence B whose data amount can be specified, the process proceeds to step 202; After performing the process corresponding to A ′, the process ends.

In the interrupt prohibition processing of step 202,
An interrupt prohibition instruction 81 for the reception interrupt 80 is issued to the interrupt controller 4 to prohibit the operation of the interrupt processing unit 5 and then the process proceeds to step 203.

In the data string acquisition processing of step 203,
The data string B ′ stored in the reception buffer 52 is obtained. If the amount of the data string B 'is equal to the amount of the data string B, that is, if all of the data string B can be obtained from the reception buffer 52, the process proceeds to step 207; otherwise, the process proceeds to step 204.

In the reception monitoring start process at step 204,
A reception monitoring command 84 for the remaining data sequence B ″ is issued to the reception monitoring unit 63, and the process proceeds to step 205.

In the reception monitoring process in step 205, the data reception circuit 3 is constantly monitored by the reception monitoring unit 63, and the data reception circuit 3 is connected to the external terminal device 2 and the remaining data string B ″.
It is checked whether or not it has been received. If it has been received, the process proceeds to step 206.

In the data amount check in step 206, it is checked whether or not all of the data string B ″ has been received by receiving the received data from the data receiving circuit 3. If all of the data strings B ″ have been received, the process proceeds to step 207, otherwise. In this case, the process returns to step 205.

In the reception monitoring termination processing of step 207,
A reception monitoring end command is issued to the reception monitoring unit 63, and the process ends.

As described above, according to the present embodiment, when the data sequence B that can specify the data amount is received, the reception processing is performed by the main processing unit 6 without passing through the reception interrupt 80 and the interrupt processing unit 5. Therefore, the reception processing time is not limited in relation to other interrupt processing. Therefore, a sufficiently high-speed data receiving device can be realized.

Since no additional hardware is required, the cost of the product can be reduced.

The data receiving apparatus of the present invention is not limited to the printer as in the present embodiment, but can be implemented by various apparatuses.

[0036]

As described above, according to the data receiving apparatus of the present invention, when a data string such as image data is received, the data is directly received without a time-consuming interrupt process. Can be received at a high speed, and the waiting time can be greatly reduced. Further, since it is not necessary to add hardware such as a DMA circuit, the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a data receiving device of a printer according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an operation of a reception buffer control unit according to one embodiment of the present invention.

FIG. 3 is a flowchart illustrating an operation of a main processing unit according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Printer 2 External terminal device 3 Receiving circuit 4 Interrupt controller 5 Interrupt processing part 51 Reception buffer control part 52 Reception buffer 6 Main processing part 61 Reception data analysis part 62 Data string processing part 63 Reception monitoring part 7 Image memory A Reception data A ' Received data stored in the receive buffer B Data string B 'Data string stored in the receive buffer B''Remaining data string not stored in the receive buffer

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41J 5/30 G06F 3/12

Claims (4)

(57) [Claims] 1. A CPU built in a data receiving apparatus main body.
And a data receiving circuit for receiving data transmitted from the external terminal device. The data receiving circuit detects that the data receiving circuit has received the transmitted data from the external terminal device and generates an interrupt to the CPU. Data reception detection means, reception data storage means for receiving the interrupt, acquiring the transmission data from the data reception circuit, and storing the transmission data as reception data in a reception buffer, and analyzing the reception data to obtain an effective data for the data reception device. Receiving data analysis means for acquiring data or control commands; and a data amount specified by the data or control commands.
Data string processing means for processing the data string, the data receiving apparatus the data receiving circuit and having a reception monitoring means for monitoring the reception of the data sequence from the external terminal device. 2. When the data string processing means cannot acquire all of the data strings from the reception buffer,
2. The data receiving apparatus according to claim 1, wherein the remaining data string is obtained by the reception monitoring means without passing through the data reception detection means and the reception data storage means. An information processing device including a CPU for performing a series of control operations; a data receiving circuit for generating an interrupt to the information processing device when receiving data from the outside; A receiving buffer for receiving and storing data; determining means for determining whether the data is a control command and having a predetermined data amount; and wherein the determining means is the control command; and A data receiving apparatus comprising: a reception monitoring unit that prohibits the interrupt when it is determined that the data amount has a predetermined amount and receives external data without passing through the reception buffer. 4. The data receiving apparatus according to claim 3, further comprising a memory for storing data stored in said reception buffer and data received by said reception monitoring means.