JPH04330515A - Printer controller - Google Patents

Abstract

PURPOSE:To realize emulation switching free from data disappearance even when a specific memory is not used. CONSTITUTION:At the time of receiving effective data following an emulation switching instruction received from a host device in the case of processing the instruction, the effective data are saved in an address previously set up in a buffer memory, and when switched emulation has control right by the emulation switching instruction, an input buffer initialized at the time of initializing the buffer memory and then the effective data saved in the address are returned to the input buffer.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer control device connected to a host device and a printer engine in a printer such as a laser printer.

0002

[Prior Art] For example, in a printer control device for a laser printer, print data and control commands received from a host device such as an office computer, a personal computer, a word processor, a data processing device, an image processing device, etc. are temporarily stored in an input buffer. Based on the stored print data and control instructions, a data processing means (emulation) using a microcomputer (CPU) and its control program creates image data, and transfers it to the printer engine for printing. The image is output.

[0003] In such a printer control device,
Some devices are equipped with multiple emulations and can create various types of image data by switching to the emulation specified by a data processing switching command (emulation switching command) in a control command received from the host device. .

By the way, the data that the printer receives includes print data and various control commands including immediate processing commands and emulation switching commands. Immediate processing instructions refer to reset and status request instructions. Received data other than immediate processing instructions are stored in the input buffer through the preprocessor, but the immediate processing instructions are separated from other received data by the preprocessor, are not stored in the input buffer, and are immediately processed.

[0005]

[Problems to be Solved by the Invention] However, in such a printer control device, various initializations including clearing the RAM area including the input buffer are performed when switching the emulation.
In particular, when switching emulation is performed by an emulation switching command from the host device, if other data is subsequently sent immediately after that command and is stored in the input buffer, during the initialization process described above, There is a problem in that this received valid data is lost.

[0006] Therefore, the present applicant first proposed that when switching processing of data processing means is performed by a data processing switching command from a host device, if there is valid data in the input buffer, that data is saved in a non-volatile memory. After letting
After switching the data processing means and initializing the memory, the data saved in non-volatile memory is returned to the input buffer, so that valid data sent from the host device following the data processing switching command is not lost. has proposed a data processing switching system in a printer control device (Japanese Patent Application No. 1-325314).

However, with this method, it is necessary to prepare a non-volatile memory as a save destination for valid data, and there is a problem in that it increases the cost of the printer because it uses expensive memory in addition to ordinary RAM. .

On the other hand, emulation switching instructions that process a specific instruction set have conventionally been sequentially stored in an input buffer along with other received data, and data received after the emulation switching instruction is processed by that instruction. These are emulation control commands and print data after switching.

Therefore, the immediate processing command received at that point is the immediate processing command of the emulation after switching,
It should be processed immediately when control is passed to the emulation, but since the preprocessor only determines the instruction set of the emulation before switching, this immediate processing instruction is stored in the input buffer as data. It didn't make much sense as an immediate process.

[0010] That is, the emulation switching instruction is also F
Because it is stored once in the IFO structure input buffer and then processed, before the emulation switching instruction is processed (when the emulation switching instruction exists in the input buffer), the command for the emulation after switching is When an immediate processing instruction is sent, this instruction is stored in the input buffer like other instructions or data, so even if the emulation is switched to a new emulation using the emulation switching instruction,
Immediate processing was sometimes not performed using an immediate processing command.

[0011] Furthermore, even if the immediate processing instructions of each emulation before and after switching are the same code,
Immediate processing is performed at the time the command is received, that is, before the switched emulation has control authority. Alternatively, in order to perform processing under the control of the emulation before switching from receiving an emulation switching command until switching to a new emulation, data from the emulation after switching is processed as an immediate processing command for the emulation before switching. This has the disadvantage that the results may not be what you intended.

The present invention has been made in view of the above points, and it is possible to realize emulation switching without data loss without using a special memory, and to receive an emulation switching command from a host device. Another purpose is to enable the immediate processing command to be processed immediately by the emulation after the switching processing even if an immediate processing command is received from the host device between the time when the emulation switching processing by that command is completed. shall be.

[0013]

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned problems, and provides a printer control device equipped with a plurality of data processing means and a data processing switching means for switching between them as described above. When the data processing switching means processes a data processing switching command from the host device, it subsequently determines whether data for the data processing means after switching has been received by the data processing switching command. means for saving the data to a preset address in the memory when the data is determined to have been received by the data processing means, and the data processing means after switching is controlled by the data processing switching command. When initializing the memory, which is performed when the input buffer has the right, there is a means for determining whether the input buffer area has been initialized, and if it is determined by the means that the area has been initialized, it is saved to the above address. A means for returning the data to the input buffer is provided.

[0014] The present invention also includes means for determining whether or not the received data is a data processing switching instruction immediately before temporarily storing the data received from the host device in the input buffer; means for changing the means for interpreting the subsequent data to the means for interpreting the commands of the data processing means after switching, when the data processing switching command is determined, and the immediate processing command for the data processing means after switching. means for determining whether or not an immediate processing instruction has been received; and when it is determined by the means that an immediate processing instruction for the switched data processing means has been received, the immediate processing instruction is temporarily stored at a preset address in the memory; It is preferable to provide a preprocessor having means for first retrieving the immediate processing command stored at the address when the data processing means after switching has control authority due to the data processing switching command.

[0015]

[Operation] According to the printer control device of the present invention, when processing a data processing switching command from a host device, and subsequently receiving data for the data processing means after switching due to the data processing switching command, In the initialization of the memory, which is performed when the data is saved to a preset address in the memory and the data processing means after switching has control authority by the data processing switching command,
After the input buffer area is initialized, the data saved at the above address is returned to the input buffer, so when the data processing switching command is sent from the host device during the initialization processing that is performed together with the switching processing of the data processing means, Even if valid data is subsequently received, the data can be prevented from being lost. Furthermore, since a part of the normal RAM is used as the save destination for valid data, there is no need to increase costs.

[0016] Immediately before data received from the host device is temporarily stored in the input buffer, it is checked whether the received data is a data processing switching command, and if it is a data processing switching command, the subsequent data is interpreted. The means for interpreting the command of the data processing means after switching is changed by the data processing switching command to a means for interpreting the command of the data processing means after switching, and when an immediate processing command of the data processing means after switching is received, the immediate processing command is stored in the memory. If the data processing means is temporarily stored in a preset address of the host, and when the data processing means after switching has control authority by the data processing switching command, the immediate processing command stored in the above address is retrieved first. Even if an immediate processing command for emulation after switching is sent by that command between the time a data processing switching command is received from the device and the time when the data processing means is switched by that command, the above-mentioned There is no possibility of various problems occurring.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 2 is a block diagram showing the configuration of a printer control device for a laser printer embodying the present invention.

This printer control device (printer controller) 1 includes interface circuits such as a host interface 2, a panel interface 3, and an engine interface 4, a microcomputer (hereinafter abbreviated as "CPU") 5, a program ROM 6, a font ROM 7,
Buffer memory 8, output buffer 9, and connector 10~
12. Note that each part except the connectors 10 to 12 is interconnected by a bus line 13 consisting of an address bus, a control bus, and a data bus.

The host interface 2 is a connector 10
It is an interface circuit for managing the transmission and reception of various control commands and data with the host computer (host device) 14 via the host computer (host device), and selects various serial interfaces or parallel interfaces according to the host computer to be connected. The panel interface 3 transmits display control data to and from the operation display panel 15 via the connector 11 and receives each key information. The engine interface 4 is in charge of sending and receiving data such as commands and status information to and from the printer engine 16 via the connector 12.

The CPU 5 is a general-purpose 16 or 32-bit central processing unit, and is in charge of overall control of the printer control device 1 as a whole. This CPU 5 is a program R to be described later.
By using the programs stored in the OM 6, it is possible to create various types of image data based on control commands and print data received from the host computer 14. The combination of this CPU 5 and each program constitutes a plurality of emulations (data processing means).

The program ROM 6 is a read-on memory that stores a control program including a preprocessor, and the font ROM 7 is a read-on memory that stores font data. Here, the preprocessor is a part of the control program and is a program for identifying which data of which emulation is currently being received.

The buffer memory 8 is composed of a RAM, and includes a working memory of the CPU 5, an input buffer for temporarily storing control commands (excluding immediate processing commands) such as emulation switching commands received from the host computer 14, and print data; It is used as a page buffer for storing page data created based on control commands and print data temporarily stored in the input buffer, a font file for storing downloaded font data received from the host computer 14, and the like. The output buffer 9 is a memory that temporarily stores image data (video data) created page by page based on the data on the page buffer of the buffer memory 8 and the font data on the font file.

The host computer 14 is a host computer such as an office computer, a personal computer, a word processor, a data processing device, an image processing device, etc., and corresponds to the printer control device 1 in order to print document information etc. created in these devices. control commands and print data to be sent. The operation display panel 15 is
It is equipped with various operation keys and displays for inputting and outputting various information.

The printer engine 16 is an image forming unit consisting of a laser writing unit that optically scans a photoconductor with a laser beam modulated in accordance with image data, and a photoconductor and various process devices surrounding the photoconductor. It consists of a mechanism section consisting of a paper transport section, etc., which is made up of rollers such as , registration rollers, etc., and an engine driver that is its control section.The engine driver performs image formation according to commands and image data from the printer controller 1 Printing is executed by controlling the sequential operations of the unit and paper transport section and the video modulation signal to the laser writing unit.

Next, the operation of this embodiment configured as described above will be explained. FIG. 1 is a flowchart showing the processing according to the present invention by the CPU 5 in FIG. 2. This routine starts when data is received from the host computer 14 and stored in the input buffer on the buffer memory 8. It reads each byte and determines whether it is a control command or not.

[0026] If the data is not a control command but print data, after executing print processing, that is, data processing for creating image data according to the print data, the process returns to the step of determining whether it is a control command or not. Go back and repeat this process. If it is a control command, it is determined whether the control command is an emulation switching command or not, and if not, it executes each process according to the control command, and returns to the step to determine whether it is a control command. repeat.

If the control command is an emulation switching command, it is determined whether or not there is valid data in the input buffer, and if so, the valid data and its size are stored at a preset address in the buffer memory 8 (hereinafter referred to as (simply referred to as the "setting address"). Here, the valid data refers to the control command or print data received from the host computer 14 following the emulation switching command. Further, the setting address is set between the current emulation and the new emulation in an area other than the input buffer for the new emulation after switching.

Next, the emulation is switched, and after control is handed over to the new emulation, initialization of the buffer memory 8 is started, and then it is determined whether or not there is valid data at the set address, and the control is transferred to the new emulation. For example, during initialization, it is determined whether the area of the new input buffer has been initialized or not, and if it has been initialized, valid data is retrieved from the set address where the size has been saved, and it is returned to the input buffer.

FIGS. 3 and 4 are flowcharts showing processing performed by the CPU 5 of FIG. 2 that is different from that shown in FIG. (which determines the instruction set of) determines whether the data is an immediate processing instruction, and if it is an immediate processing instruction, immediate processing is started.

If the data is not an immediate processing instruction, then it is determined whether the data is an emulation switching instruction, and if it is not an emulation switching instruction, the data is directly transferred to the input buffer secured in the buffer memory 8. If it is an emulation switching instruction, the emulation switching instruction is temporarily stored in the input buffer after switching to the processor Y which determines the instruction set of the emulation after switching based on the instruction.

The data stored in the input buffer is read by a normal program, and it is interpreted whether the data is a control command or print data.If the data is a control command, various processes are performed, and if it is print data, print processing is performed. A combination of this control command and its corresponding processing constitutes emulation.

After switching to preprocessor Y, it is checked whether all previous emulation processing has been completed, and when it has been completed, it is time for emulation switching processing to be performed, so the emulation switching routine is entered. In addition, if the processing of the previous emulation has not been completed, the received data is sequentially received, and if an immediate processing command is received, the immediate processing command and its size are stored at a preset address A in the buffer memory 8.
If data other than an immediate processing instruction is received, that data is temporarily stored in the input buffer.

After that, when the previous emulation processing is completed, the emulation switching routine is entered and the buffer memory (RAM) is initialized, but before the initialization processing is performed, it is checked whether there is valid data in the input buffer. If any, the valid data and its size are temporarily saved in a preset address B of the buffer memory 8. Here, the setting address B is set together with the setting address A in an area other than the input buffer for the new emulation after switching, between the current emulation and the new emulation.

[0034] After that, the emulation is switched, and after control is handed over to the new emulation, initialization of the buffer memory 8 is started, and then it is determined whether or not there is valid data at the set address B. If so, it is determined during initialization whether the area of the new input buffer has been initialized or not, and if it has been initialized, valid data corresponding to the size is taken out from the address B where it was saved and returned to the input buffer.

Next, it is determined whether or not there is an immediate processing instruction at the set address A, and if so, the immediate processing instruction is taken out for the size and immediate processing is started, and normal data processing is started by new emulation.

The embodiments in which the present invention is applied to a printer control device for a laser printer have been described above, but the present invention is applicable not only to other optical printers such as LED printers and liquid crystal shutter printers, but also to wire dot printers, thermal printers, The present invention is applicable to dot printers such as inkjet printers, and various printer control devices connected to a host device and a printer engine, such as a printer section of a digital copier, respectively.

[0037]

[Effects of the Invention] As explained above, according to the present invention, when switching emulations, valid data received following the switching command is temporarily saved to a preset address in normal memory. Therefore, emulation switching without data loss can be achieved without using special memory.

According to the second aspect of the invention, if an immediate processing command is received from the host device after the emulation switching command is received from the host device and until the emulation switching processing according to the command is completed. However, since the immediate processing command can be immediately processed by emulation after switching processing, the conventional problems described above can be solved.

[Brief explanation of drawings]

FIG. 1 is a flow diagram showing processing according to the present invention by a CPU 5 in FIG. 2;

FIG. 2 is a block configuration diagram showing a printer control device for a laser printer embodying the present invention.

FIG. 3 is a flowchart showing processing different from that in FIG. 1 according to the present invention by the CPU 5 in FIG. 2;

FIG. 4 is a flow diagram showing a continuation of the process in FIG. 3;

[Explanation of symbols]

1 Printer control device (printer controller) 5
Central processing unit (CPU) 6 Program R
OM7 Font ROM 8
Buffer memory 9 Output buffer
14 Host computer (host device) 16 Printer engine

Claims (2)

[Claims] 1. An input buffer that is connected to a host device and a printer engine and temporarily stores print data and control instructions received from the host device; A plurality of data processing means that create image data based on the data processing means, and a data processing switching command included in a control command received from the host device, perform processing of switching the plurality of data processing means and clearing the input buffer. a data processing switching means for performing initialization, and transmitting image data created by any of the plurality of data processing means to the printer engine to output a printed image, wherein the data processing switching means When the means processes a data processing switching command from the host device, subsequently determining whether data for the data processing means after switching has been received by the data processing switching command; means for saving the data to a preset address in the memory when it is determined by the means that the data has been received, and a data processing means after switching by the data processing switching command having control authority. means for determining whether the input buffer area has been initialized during memory initialization performed when the input buffer is initialized, and data saved at the address when the input buffer area is determined to have been initialized A printer control device comprising: means for returning the input buffer to the input buffer. 2. The printer control device according to claim 1, further comprising means for determining whether the received data is a data processing switching command immediately before the data received from the host device is temporarily stored in the input buffer. and means for changing the means for interpreting the subsequent data to the means for interpreting the command of the data processing means after switching by the data processing switching command, if the means determines that it is a data processing switching command; means for determining whether or not an immediate processing command of the switched data processing means has been received; and when the means determines that an immediate processing command of the switched data processing means has been received, immediate processing thereof; Means for temporarily storing an instruction at a preset address in the memory, and when the data processing means after switching has control authority due to the data processing switching instruction, first retrieves the immediate processing instruction stored at the address. 1. A printer control device comprising a preprocessor having means.