JPH09259079A - Communication controller, communication control method, and memory - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set whether or not to actually use respective supported modes in a communication protocol provided with the plural modes by providing a responding means for responding whether or not the mode inquired from a host device is supported to the host device according to a setting means for setting whether or not to use the plural modes for communication with the host device or the like. SOLUTION: A laser beam printer(LBP) 1 is composed of a printer controller 3, an engine 4, panel device 5 and a disk device 6 and is connected to an external host 2. A CPU 7 performs control based on the respective kinds of control programs stored in a PROM 8 and a program or the like referred to by the CPU 7 in the scene of deciding by using which mode the communication is to be performed is stored in the PROM 8. When whether or not a certain mode is supported is inquired from the host 2 to the LBP 1, interruption-informing is performed to the CPU 7 for instructing to respond whether or not the mode is supported is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication control device, a communication control method, and a memory for communicating with a host device using a communication protocol having a plurality of modes.

[0002]

[Prior Art] Centronics I / F (Centro)
Is one of the main I / Fs that send and receive data between the host computer (hereinafter, host) and the printer. In the Centro, there has been a communication protocol for transmitting data from a host to a printer, and it has been widely used as a means for transmitting data from a personal computer (PC) to the printer. However, this communication protocol only supports one-way from the host to the printer, and there is a drawback that data transfer from the printer to the host is not possible.

Therefore, in order to improve the fact that the data cannot be transferred from the printer to the host, the Centro bidirectional communication protocol is defined by IEEE in the form of upward compatibility of the existing transmission protocol from the host to the printer by the Centro. It is defined (IEEE P1284). The Centro's two-way communication protocol is one of the traditional host-to-printer communication protocols.
(This is called a compatible mode), and a plurality of communication modes such as a nibble mode, a byte mode, and an ECP mode are newly added and defined. Since both the host and printer are equipped with the Centro I / F, it can be said that at least the compatible modes are supported.

The nibble mode is a protocol for communication from the printer to the host, and bidirectional communication between the host and the printer is possible by alternately using the compatible mode. That is, bidirectional communication can be performed by transmitting data from the host to the printer in the compatible mode and transmitting data from the printer to the host in the nibble mode.

Like the nibble mode, the byte mode is a protocol for communication from the printer to the host.
By alternately using the compatible mode, bidirectional communication between the host and the printer is possible. That is, bidirectional communication can be performed by transmitting data from the host to the printer in the compatible mode and transmitting data from the printer to the host in the nibble mode.

The ECP mode is a protocol for both communication from the host to the printer and communication from the printer to the host. Internally, the Forward Phase
By switching between (Host to Printer) and Reverse Phase (Printer to Host), bidirectional communication is possible in the same ECP mode.

That is, as a method of communication from the host to the printer, it is possible to select and use one of at least two types of protocols: compatible mode and ECP mode (Forward Phase).

As a method of communication from the printer to the host, at least one of Nibble mode, Byte mode, and ECP mode (Reverse Phase) can be selected and used. Of the plurality of modes, which mode is actually used for communication can be proposed from the host to the printer. However, not all printers support all modes, so if the printer doesn't support the mode suggested by the host, then it doesn't, and so on. The printer may refuse to use the proposed mode. That is, the mechanism is such that communication is performed using a mode supported by both parties under the initiative of the host.

For the sake of clarity, the host processing and the printer processing in the scene of deciding which mode to use will be described.

First, an example of processing of a host that supports all of the ECP mode, Byte mode, Nibble mode, and compatible mode will be described using the flowchart shown in FIG.

First, in step 201, the host asks the printer if it supports the ECP mode. Here, control is known according to the response of the printer. That is, if the printer replies that it supports the ECP mode, it proceeds to step 202 and decides to use the ECP mode for bidirectional communication.

On the other hand, in step 201, the printer E
If it responds that it does not support CP mode, it proceeds to step 203 and asks the printer if it supports Byte mode. Here, control is known according to the response of the printer. That is, the printer is By
If you respond that it supports te mode, step
Proceed to 204, and decide to perform bidirectional communication using a combination of Byte mode and compatible mode.

On the other hand, in step 203, the printer B
If it responds that it does not support yte mode, it proceeds to step 205 and asks the printer if it supports Nibble mode. Here, control is known according to the response of the printer. That is, when the printer responds that it supports the Nibble mode, the process proceeds to step 206, and it is determined to use the Nibble mode and the compatible mode in combination to perform the bidirectional communication.

On the other hand, in step 205, the printer
If the response is that the ibble mode is not supported, the process proceeds to step 207, and it is decided to perform communication in the compatible mode. In this way, one-way communication from the host to the printer is possible with a printer that supports only the minimum compatible mode, and at least one of ECP mode, Byte mode, and Nibble mode is supported. Bidirectional communication is possible with the printer. Also, ECP mode, Nibble mode, Byt
Even if the host does not support one or more of the e-modes, it will only query the printer for the modes that the host itself supports, so the printer does not support it but the printer does. It does not decide to communicate in the current mode.

Next, using the flowchart shown in FIG. 3, when the host inquires about the mode to be used, the processing of the printer that supports all of the ECP mode, the Nibble mode, the Byte mode, and the compatible mode is performed. An example will be described. When the host asks which mode to use, the printer is interrupted.

First, in step 301, the printer
Check if the host asked if it was in Nibble mode. Also check to see if it supports Nibble mode. Here, if the host asks you for Nibble mode and it supports Nibble mode,
Proceed to step 302, and if it is supported, reply to the host. Then, the interrupt processing ends.

On the other hand, in step 301, if the inquired is not the Nibble mode, or if the Nibble mode is not supported, the process proceeds to step 303 and it is checked whether or not the host inquires is the Byte mode. Also, By
Check if te mode is supported. here,
Byte mode was asked by the host, and By
If the te mode is supported, proceed to step 302, and if it supports it, respond to the host. Then, the interrupt processing ends.

On the other hand, if it is determined in step 303 that the Byte mode is not inquired, or if the Byte mode is not supported, the process proceeds to Step 304 and it is checked whether or not the host inquires is the ECP mode. Also check to see if it supports ECP mode. Here, when the host asks the ECP mode and the ECP mode is supported, the process proceeds to step 302, and the host responds that it is supported. Then, the interrupt processing ends.

On the other hand, if it is determined in step 303 that the ECP mode is not asked, or if the ECP mode is not supported, the process proceeds to step 305 and a response is made that it is not supported. Then, the interruption ends.

In this way, the printer responds that it supports the mode supported by the host when asked by the host, and does not support the mode when asked for other modes. Is working to respond.

The processing of the host and the printer in the scene of deciding which mode to use has been described above with reference to the flowcharts of FIGS. 2 and 3. Then, the host and the printer communicate with each other using the mode thus determined.

[0022]

However, in the I / F between the host and the printer, even if the same mode is used in the same printer due to a timing difference,
There were rare cases where a problem such as normal data communication with a certain host but normal data communication with another host did not occur. When investigating such a host and printer that can not communicate normally,
There was a case where communication was possible in a specific mode but not in another mode. In many cases, the host always asks the printer for supported modes in the same order. Normal communication is not possible in the mode in which the host inquires first, but normal communication in the mode inquired later. In such a case, there is a problem that communication is always performed in a mode in which normal printing cannot be performed.

In order to solve the above problems, the present invention provides
An object of the present invention is to provide a communication control device, a communication control method, and a memory capable of setting whether or not to actually use each supported mode among communication protocols having a plurality of modes.

[0024]

In order to achieve the above object, a communication control device of the present invention is a communication control device having an interface section for communicating with a host device using a communication protocol having a plurality of modes. Setting means for setting whether or not to use the plurality of modes for communication with the host device, and whether or not the mode inquired by the host device is supported according to the contents set by the setting means. It is characterized by having a judging means for judging and a responding means for responding to the upper apparatus whether or not the mode inquired by the upper apparatus is supported according to the judgment of the judging means.

Further, the communication control method of the present invention is a communication control method for communicating with a host device using a communication protocol having a plurality of modes, and whether or not the plurality of modes are used for communication with the host device. Setting process to set or
In accordance with the contents set in the setting step, a judgment step for judging whether or not the mode inquired by the host apparatus is supported, and in accordance with the judgment in the judgment step, the mode inquired by the host apparatus is supported. And a response step of responding to the higher-level device whether or not it is.

The memory of the present invention is a memory accessed by a microprocessor that stores a program for communicating with a host device using a communication protocol having a plurality of modes. A setting program for setting whether or not to use for communication with, and a determination program for determining whether or not the mode inquired from the host device is supported according to the contents set by the setting program, According to the judgment of the judgment program, a response program for responding to the upper device whether or not the mode inquired by the upper device is supported is stored.

According to the present invention, whether or not each of the supported modes is actually used is judged according to a preset value, and the host operates in response.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram for explaining the configuration of a printing apparatus showing an embodiment of the present invention.
For example, the case of a laser beam printer is shown, and it can be applied to other types of printers such as an inkjet printer.

In FIG. 1, reference numeral 1 denotes a laser beam printer (hereinafter referred to as LBP), which comprises a printer controller 3 (hereinafter referred to as controller), an engine 4, a panel device 5, and a disk device 6. Further, it is connected to an external host 2 and is configured to receive print data and the like from the host 2 and execute print processing.

In the controller 3, the CPU 7 controls each part based on various control programs stored in the PROM 8. Further, the PROM 8 also stores a program related to a later-described flowchart referred to by the CPU 7 when deciding which mode to use for communication.

The host interface 11 (hereinafter, the interface is referred to as I / F) is an I / F that communicates with the host 2 such as print data.

The engine I / F 12 is an I / F that communicates with the engine 4 that actually prints.

The panel I / F 13 is an I / F that communicates instructions and status with the panel device 5 for indicating the status of the LBP 1 to the operator and for designating the change of the printing environment to the LBP 1 by the operator. It is F. The disk I / F 14 is an I / F for communicating with the disk device 6.

The optional memory 9 is a removable memory for storing fonts, etc.
M, FLASH memory, etc.

Reference numeral 10 denotes a RAM, which is set by a frame buffer 10a for storing image data developed based on print data, a receive buffer 10b for temporarily storing data such as print data input from the host 2, and a panel device 5. Areas such as a usage mode setting value 10c for storing whether to use each Centro mode are reserved. The RAM 10 is also used as a work area for the CPU 7.

The panel device 5 has a liquid crystal panel display for displaying information such as the status of the LBP1 as a character string, various operation buttons for the operator to perform various operations on the LBP1, a paper feeding place and an online / online It is equipped with an LED to inform the operator of offline conditions. Further, the operator can specify, via the panel device 5, whether to use each of the Centro modes.

The disk device 6 is an external storage device for storing various data, and is a hard disk device, a magneto-optical disk device, a floppy disk device, or the like.

The engine 4 is a device that actually prints image data on a recording medium.

The LBP1 is supplied with electric power from a power source unit (not shown).

From the host 2 via the host I / F 11
When an inquiry is made as to whether or not a certain mode is supported in LBP1 (see FIG. 2), an interrupt notification is issued to the CPU7 to instruct a response as to whether or not the mode is supported. . The response process executed by the controller 3 in this case will be described with reference to the flowchart shown in FIG.

When the host 2 issues an interrupt notification instructing a response as to whether or not the mode is supported, the CPU 7
In step 401, the host asked N
Check if it is in ibble mode. Also check to see if it supports Nibble mode. Here, if the host asks for the Nibble mode and it supports the Nibble mode, the process proceeds to step 402, and it is checked whether the use mode setting value 10c is a setting for using the Nibble mode. Here, the control is known depending on whether the setting uses the Nibble mode. That is, if the setting is to use the Nibble mode, proceed to step 403 and respond to the host if it is supported. Then, the interrupt processing ends.

On the other hand, if it is determined in step 402 that the Nibble mode is not used, the process proceeds to step 404. If the Nibble mode is not supported in step 401, or if the Nibble mode is not inquired, the process proceeds to step 404.

In step 404, it is checked whether or not the host inquires is the Byte mode. Also, check whether Byte mode is supported. Here, when the host asks for the Byte mode and supports the Byte mode, the process proceeds to step 405, and it is checked whether the use mode setting value 10c is a setting for using the Byte mode. Here, the control is known depending on whether or not the setting uses the Byte mode. That is, when the setting is to use the Byte mode, the process proceeds to step 403, and if the setting is supported, a response is sent to the host. Then, the interrupt processing ends.

On the other hand, if it is determined in step 405 that the Byte mode is not used, the process proceeds to step 406.
If the Byte mode is not supported in Step 404, or if the inquired is not the Byte mode, the process proceeds to Step 406.

In step 406, it is checked whether or not the host inquires is the ECP mode. Also check to see if it supports ECP mode. Here, when the host asks the ECP mode and the ECP mode is supported, the process proceeds to step 407 and it is checked whether the use mode setting value 10c is a setting to use the ECP mode.
Here, control is known depending on whether or not the ECP mode is used. That is, if the setting is to use the ECP mode, proceed to step 403 and respond to the host if it is supported. Then, the interrupt processing ends.

On the other hand, if it is determined in step 407 that the ECP mode is not used, the process proceeds to step 408. Also, in step 406, if ECP mode is not supported, or if it was not ECP mode that was asked,
Proceed to step 408.

Then, in step 408, the host is replied that it is not supported. Then, the interrupt processing ends.

In this way, the printer does not support the mode inquired by the host if it is the mode supported by itself and the mode set by the use mode setting value. Is working to respond to the host, otherwise it does not support it. This determines which mode is used for communication between the host and the printer.

As described above, after the mode to be used for communication is determined, data is actually transmitted from the host to the printer and the operation until the printing process is performed,
This will be explained below.

When data is input from the host 2 to the LBP1 via the host I / F 11, the CPU 7 is notified of an interrupt instructing storage of the input data. The process of storing the input data executed by the controller 3 in this case will be described with reference to the flowchart shown in FIG.

When an interrupt notification is issued from the host 2 to store the input data, the CPU 7 stores the input data in the receive buffer 10a via the host I / F 11 in step 501. When all the input data have been stored, the interrupt process ends. As a result, every time data is input from the host 2, an interrupt causes a reception buffer 10a.
Input data will be stored in.

Next, an outline of the printing process performed by the LBP1 when the input data from the host 2 is stored in the reception buffer 10a by the above input data storage interrupt will be described with reference to FIG.

When the CPU 7 recognizes that the input data is stored in the reception buffer 10a, it refers to the print data analysis program stored in the PROM 8 and refers to the reception buffer 10a.
It interprets the print data stored in a and converts it into image data. The image data converted by the CPU 7 is stored in the frame buffer 10c.

The CPU 7 continues the processing by referring to the print data analysis program as described above, but when it finds the paper discharge command in the print data, it outputs the frame buffer 10c.
The image data stored in is sent to the engine 4 via the engine I / F 12.

When the engine 4 receives the image data sent from the CPU 7 via the engine I / F 12, it prints out the image data on an actual recording medium.

As described above, when the data is input from the host 2, the LBP 1 performs the printing process and the image data is actually output to the recording medium.

As described above, regarding the mode in which the host asks if the printer supports it,
When responding whether or not it is supported, the user operates by referring to the use mode setting value 10c preset by the user.

Here, a specific example of the use mode set value 10c will be described.

The use mode set value 10c takes any value from 0 to 15 as follows. The user operates the panel device 5
Any of the numerical values can be set by the operation of.

Specifically, when the use mode setting value 10c is 0, all modes are not used, when it is 1, only compatible mode is used, and other modes are not used. Only Nibble mode is used, other modes are not used. In case of 3, compatible mode, N
Use only ibble mode, do not use other modes, if 4, use only Byte mode, do not use other modes, if 5, use compatible mode, Byt
Use only e mode, do not use other modes, use 6 only use Nibble mode, Byte mode, use no other mode, use 7 use compatible mode, Nibble mode, Byte mode only , Other modes are not used, in case of 8, only ECP mode is used,
Other modes are not used, 9 is compatible mode and ECP mode only, other modes are not used, 10 is Nibble mode and ECP mode only, other modes are not used, 11 In case of, use compatible mode, Nibble mode, ECP mode only, other modes are not used, in case of 12, only Byte mode, ECP mode are used, other modes are not used, in case of 13, compatible Mode, Byte mode,
Only use ECP mode, no other modes, 1
In case of 4, only Nibble mode, Byte mode and ECP mode are used and other modes are not used. In case of 15, compatible mode, Nibble mode, Byte mode and ECP mode are all used. By setting a value from 0 to 15, compatible mode, Nibble mode, By
You can set whether to use for each of te mode and ECP mode.

Also, when the setting of "Saw-nosed swordfish" is selected by the panel device, 1 is set,
If you select the setting "Sourcing
If 15 is set, “Short-snowed sea urchin” is set, and further, “ECP sea urchin” is set,
The format may be such that 7 is set.

As described above, when normal communication cannot be performed in one mode but normal communication can be performed in another mode, communication is performed in another mode by setting the mode in which normal communication cannot be performed. By doing so, normal communication becomes possible.

(Other Embodiments of the Invention) In the embodiment of the invention described above, an example in which whether or not each mode is used individually can be set as the use mode setting value has been shown. The mode may be set so that only the mode is not used. For example, if the use mode set value 10c is 0, only compatible mode is used, other modes are not used.If the use mode set value 10c is 1, compatible mode, Nibb
Only the le mode and the Byte mode are used, the other modes are not used, and when the use mode setting value 10c is 2, the compatible mode, the Nibble mode, the Byte mode, and the ECP mode may be used. Similarly, for example, when the use mode setting value 10c is 0, only compatible mode is used, other modes are not used, when the use mode setting value 10c is 1, only compatible mode and Nibble mode are used. , The other modes are not used, and when the use mode setting value 10c is 2, only the compatible mode, the Nibble mode, and the ECP mode are used, and the other modes are not used. This can be set relatively easily as compared with the case of setting whether or not to use for all modes as in the above-described embodiment. This is particularly effective when the communication results differ depending on the mode.

For example, a mode having a considerable communication record (compatible mode), a mode having a certain record of communication (Nibble mode), a mode having little record of communication (E
If there is a situation such as (CP mode), it is most likely that a failure will occur in a mode that has almost no track record, and the possibility that a failure will occur next in a mode that has some communication history is the next This is because it can be said that there is almost no possibility of a malfunction occurring in a certain mode.

Further, in the embodiment of the present invention described above, an example in which the mode to be used is set from the panel is shown, but the setting means is not limited to this, and any means may be used. For example, you may specify on the display screen on a host computer.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of a single device. Further, it goes without saying that the present invention can be applied to the case where it is implemented by supplying a program to a system or an apparatus. In this case, the storage medium storing the program according to the present invention constitutes the present invention. Then, by reading the program from the storage medium to the system or device, the system or device functions in a specific mode.

[0067]

As described above, according to the present invention,
According to the setting, it determines whether to actually use each mode supported by the communication protocol having multiple modes, and operates to respond to the host, so normal communication cannot be performed in one mode but another mode is used. Then, when normal communication is possible, by setting not to use a mode in which normal communication cannot be performed, it becomes possible to communicate in another mode and perform normal communication.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a configuration of a printing apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a conventional example of a processing procedure of a host when deciding a mode to be used.

FIG. 3 is a flowchart illustrating a conventional example of a response processing procedure of the printing apparatus when the host inquires about a mode to be used.

FIG. 4 is a flowchart showing a response processing procedure of the printing apparatus according to the exemplary embodiment of the present invention.

FIG. 5 is a flowchart showing an interrupt process of an input data storage instruction.

[Explanation of symbols]

 1 LBP 2 host device 3 printer controller 4 engine 5 panel device 6 disk device 7 CPU 8 PROM 9 option memory 10 RAM 10a frame buffer 10b reception buffer 10c use mode setting value 11 host I / F 12 engine I / F 13 panel I / F 14 Disk I / F

Claims (15)

[Claims] 1. A communication control device having an interface section for communicating with a host device using a communication protocol having a plurality of modes, wherein whether or not to use the plurality of modes for communication with the host device is set. Setting means, judging means for judging whether or not the mode inquired by the host device is supported according to the contents set by the setting means, and an inquiry from the host device is made according to the judgment of the judging means. And a response means for responding to the upper device whether or not the supported mode is supported. 2. The communication control device according to claim 1, wherein the setting means sets whether or not to use only one or more specific modes that are not all of the plurality of modes. 3. The communication control device according to claim 1, wherein the plurality of modes are an ECP mode, a nibble mode, and a byte mode. 4. The sheet passing control device according to claim 3, wherein the upper device inquires whether or not the ECP mode, the byte mode, and the nibble mode are supported in this order. 5. The response means, even if it supports the mode inquired by the higher-level device, responds to the higher-level device that the mode is not supported by the setting means if the mode is not used. The communication control device according to claim 1, wherein: 6. The communication control apparatus according to claim 3, wherein the setting unit makes a setting to prohibit the use of the ECP mode. 7. The communication control device according to claim 1, further comprising a printing unit that prints based on print data received from the higher-level device. 8. A communication control method for communicating with a host device using a communication protocol having a plurality of modes, a setting step of setting whether or not to use the plurality of modes for communication with a host device, According to the contents set in the setting step, a judgment step of judging whether or not the mode inquired from the host device is supported, and a mode inquired from the host device is supported in accordance with the judgment of the judgment step. And a response step of responding to the host device whether or not the communication control method is performed. 9. The communication control method according to claim 8, wherein the setting step sets whether or not to use only one or more specific modes that are not all of the plurality of modes. 10. The communication control method according to claim 8, wherein the plurality of modes are an ECP mode, a nibble mode, and a byte mode. 11. The paper feed control method according to claim 10, wherein the host device inquires whether or not the ECP mode, the byte mode, and the nibble mode are supported in this order. 12. The response step responds to the higher-level device that the mode is not supported even if it supports the mode inquired by the higher-level device but is not supported by the setting means. The communication control method according to claim 8, further comprising: 13. The communication control method according to claim 10, wherein in the setting step, setting for prohibiting use of the ECP mode is performed. 14. The communication control method according to claim 8, further comprising a printing step of performing printing based on print data received from the host device. 15. A memory accessed by a microprocessor for storing a program for communicating with a host device using a communication protocol having a plurality of modes, wherein the plurality of modes are used for communication with the host device. A setting program for setting whether or not, according to the contents set by the setting program, a determination program for determining whether to support the mode inquired from the host device, according to the determination of the determination program, A memory accessed by a microprocessor, which stores a response program for responding to a higher-level device whether or not a mode inquired from the higher-level device is supported.