JPH10136186A - Image forming device and data transfer method for the image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain the performance at a high speed by conducting DMA transfer between an external I/O with low performance and a memory of high speed CPU built in memory controller control. SOLUTION: A DMA controller 100a built in a system CPU 100 and a memory controller 100b control DMA transfer of data among a main memory 104 and buffers 341, 342, 343. Then an external controller controls the DMA transfer of data among the buffers 341, 342, 343, a facsimile interface 331, a printer interface 332, and an extension interface 333.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital copying machine having, for example, a copying function, a scanner function, a printer function, a facsimile transmission / reception function, an image processing function, and a transfer function for transferring data by being connected to an external device. And the like, and a data transfer method of the image forming apparatus.

[0002]

2. Description of the Related Art In recent years, an image forming apparatus such as a digital copying machine having a copying function, a scanner function, a printer function, a facsimile transmission / reception function, an image processing function, and a communication function connected to an external device for communicating information has been developed. It is spreading rapidly.

In such a digital copying machine, in a built-in high-speed CPU having a DMA controller for controlling the entire control and a memory controller function, a DMA transfer cycle is controlled by a built-in controller in order to improve performance (performance). Then, the end of the transfer is internally transmitted to the CPU.

However, D with built-in high-speed CPU
The DMA transfer cycle controlled by the MA controller is subject to the following restrictions in order to increase the performance. 1. Does not accept a wait (WAIT) signal from an external device. 2. The number of wait cycles that can be inserted is limited by the DMA controller with a built-in CPU. 3. The DMA transfer cycle is controlled based on the system clock of the high-speed CPU.

[0005] Due to these three points, under the control of the DMA controller with a built-in CPU, DMA transfer of an external device having low performance is impossible. External I / O and CP
The following restrictions are also imposed on the DMA transfer with the memory under the control of the U built-in memory controller. 1. Does not accept wait signals from external devices. 2. The number of wait cycles that can be inserted is limited by the memory controller with a built-in CPU. 3. The DMA transfer cycle is controlled based on the system clock of the high-speed CPU.

Due to these three points, the external I / O and C, which have low performance under the control of the DMA controller with a built-in CPU,
DMA with memory under control of PU built-in memory controller
Transfer is not possible.

[0007]

As described above, in a DMA transfer cycle controlled by a DMA controller with a built-in high-speed CPU in order to speed up the performance, the control of the DMA controller with a built-in high-speed CPU is difficult. DMA transfer of an external device having a low performance is not possible due to limitations in achieving high-speed performance, and a memory under the control of a memory controller with a built-in high-speed CPU and a DMA in an external I / O having a low performance There was a problem that transfer was impossible.

Accordingly, the present invention provides an image forming apparatus and an image forming apparatus capable of achieving high-speed performance by enabling DMA transfer between an external I / O having low performance and a memory controlled by a memory controller with a built-in high-speed CPU. It is intended to provide a data transfer method.

[0009]

An image forming apparatus according to the present invention has a function of transferring data by being connected to an external device, and forms an image based on the transferred data. Storage means for temporarily storing data transferred from the device or data to be transferred to the external device; first control means for controlling transfer at a first speed between the storage device and the external device; Storage means for storing data transferred from the storage means or data to be transferred to the storage means, and transfer at a second speed higher than the first speed between the storage means and the storage means; And second control means for controlling.

[0010] The image forming apparatus of the present invention is connected to an external device to control data transfer at a second speed higher than the first speed and to have a first control means for performing overall control. In an image forming apparatus that forms an image based on data to be transmitted, a storage unit for temporarily storing data transferred from the external device or data to be transferred to the external device, and a second unit performed between the storage unit and the external device. Data transferred from the storage means or data transferred to the storage means by the second control means for controlling the transfer at the first speed and the transfer control at the second speed by the first control means. And storage means for storing

An image forming apparatus according to the present invention includes a DMA controller which is connected to an external device and controls data transfer at a second speed higher than the first speed, and a CPU which has a memory control function and performs overall control. An image forming apparatus that forms an image based on the transferred data,
A buffer for temporarily storing data transferred from the external device or data to be transferred to the external device; an external controller for controlling transfer at a first speed between the buffer and the external device; DMA provided
A controller and a memory for storing data to be transferred from the buffer or data to be transferred to the buffer by the transfer control at the second speed by the memory control function.

An image forming apparatus according to the present invention includes a DMA controller for controlling data transfer at a second speed higher than a first speed via an interface to which an external device is connected, and a memory control function to control the entire system. Do C
An image forming apparatus having a PU and forming an image based on data to be transferred, a buffer for temporarily storing data transferred from the interface or data to be transferred to the interface, and a buffer between the buffer and the interface. Data transferred from the buffer or transferred to the buffer by an external controller which controls transfer at a first speed and a transfer control at a second speed of a DMA controller and a memory control function of the CPU. And a memory for storing data.

An image forming apparatus according to the present invention has a function of transferring data by being connected to an external device, and in an image forming apparatus for forming an image based on the transferred data, the data transferred from the external device. Control means for controlling transfer of data at a first speed, storage means for temporarily storing data to be transfer-controlled by the first control means, and data stored in the storage means at a first speed. It comprises second control means for performing transfer control at a high second speed, and storage means for storing data to be transfer-controlled by the second control means.

An image forming apparatus according to the present invention has a function of transferring data by being connected to an external device, and in an image forming apparatus for forming an image based on transferred data, storage means for storing data to be transferred. First control means for controlling transfer of data stored in the storage means at a first speed, storage means for temporarily storing data to be transfer-controlled by the first control means, and storage means And second control means for controlling the transfer of the data stored in the external device to the external device at a second speed lower than the first speed.

A data transfer method for an image forming apparatus according to the present invention is a data transfer method for an image forming apparatus having a function of transferring data by being connected to an external device and forming an image based on the transferred data. The data transferred from the external device or the data transferred to the external device.
And the transfer at a second speed higher than the first speed is controlled separately.

According to the data transfer method of the image forming apparatus of the present invention, the first control means is connected to an external device to control data transfer, and the second control means controls data transfer and performs overall control. A data transfer method of an image forming apparatus for forming an image based on data transferred with the first control means, wherein the data transferred from the external device or the data transferred to the external device is The transfer control is performed at a speed of 1 and the transfer control is performed at a second speed higher than the first speed by the second control means.

A data transfer method for an image forming apparatus according to the present invention comprises a DMA controller connected to an external device for controlling data transfer at a second speed higher than a first speed, and a memory control function to control the entire system. A data transfer method for an image forming apparatus that forms an image based on data to be transferred, the data being transferred from the external device or the data to be transferred to the external device at a first speed. DM that is transferred and temporarily stored, and the temporarily stored data or the data to be temporarily stored
The transfer control is performed at the second speed by the A controller and the memory control function.

According to the data transfer method of the image forming apparatus of the present invention, the data transfer is controlled at a second speed higher than the first speed via an interface to which an external device is connected.
What is claimed is: 1. A data transfer method for an image forming apparatus, comprising: a CPU having an MA controller and a memory control function for performing overall control; and forming an image based on transferred data. The data to be transferred to the CPU is transferred at a first speed and temporarily stored, and the temporarily stored data or the data to be temporarily stored is transfer-controlled at a second speed by a DMA controller and a memory control function of the CPU. It is characterized by the following.

A data transfer method for an image forming apparatus according to the present invention is a data transfer method for an image forming apparatus having a function of transferring data by being connected to an external device and forming an image based on the transferred data. Controlling the data transferred from the external device at a first speed and temporarily storing the data;
The stored data is transferred and stored at a second speed higher than the first speed.

A data transfer method for an image forming apparatus according to the present invention is a data transfer method for an image forming apparatus which has a function of transferring data by being connected to an external device and forms an image based on the transferred data. Transfer control of the stored data at a first speed to temporarily store the stored data; and transfer control of the stored data to the external device at a second speed lower than the first speed. And

[0021]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows the entire configuration of a digital copying machine as an image forming apparatus according to the present invention. The digital copying machine 1 includes a scanner 2 as an image reading unit and a printer 3 as an image printing unit, and has an automatic document feeder (ADF) 4
Is installed.

In the automatic document feeder 4, the rear end of the cover main body 21 as a housing is attached to the rear end of the upper surface of the apparatus main body via a hinge device (not shown) so as to be freely opened and closed. In response, the entire automatic document feeder 4 is pivotally displaced to open the document table 5. A document feed table 22 capable of holding a plurality of documents collectively is provided on the upper surface of the cover main body 21 in a slightly rightward direction. At one end of the apparatus, there is provided a feeding means 23 for sequentially taking out the originals one by one and supplying the originals to one end (the left end in the figure) of the original table 5. The feeding means 23 includes a pickup roller 27 for taking out the document, a weight plate 28 for pressing the document against the pickup roller 27, an empty sensor 29 as a document detection sensor for detecting a setting state of the document on the document feed table 22, and the like. Are arranged. Further, a paper feed roller 32 is arranged in the direction of taking out the document by the pickup roller 27, so that the document is fed one by one without fail. On the upper surface of the document table 5, a document conveying belt 3 covering the document table 5
7 is installed. The document conveying belt 37 is formed of a white wide endless belt whose outer surface stretched over a pair of belt rollers 40, 40, and is configured to be able to run in both forward and reverse directions by a belt driving mechanism (not shown). A plurality of belt pressing rollers 41 for pressing the belt surface onto the document table 5 and a set switch for detecting the open / close state of the automatic document feeder are provided on the back side of the inner peripheral portion of the document conveying belt 37. (Not shown). Then, the document fed by the feeding means 23 is transported from one end (left end) of the document table 5 to the other end (right end). A paper discharging means 38 is provided on the right side of the apparatus. The paper discharging means 38 detects a conveying roller 44, a pinch roller 45 for pressing the document against the conveying roller 44, and a trailing end of the document sent in the paper discharging direction. A paper discharge sensor 46 or the like is provided as document detecting means for detecting the original. On the downstream side of the document discharge path,
A discharge roller 48 is provided. A gate 8 is provided in the document discharge path to guide the document upside down to the document table 5.
2 is provided so that the document can be copied on both sides.

The scanner 2 includes an exposure lamp 6 as a light source, a first carriage 7 provided with a mirror 15, a second carriage 9 provided with mirrors 8a and 8b for bending optical paths,
A lens 10, a CCD sensor 11 for receiving reflected light, a drive system (not shown) for changing the positions of these components, and an A / A for converting the output of the CCD sensor 11, ie, image data (information) from analog data to digital data. It is composed of a D conversion unit (not shown). The first and second carriages 7 and 9 are connected to each other by a timing belt (not shown), and the second carriage 9 moves in the same direction at half the speed of the first carriage 7. ing. Thus, scanning can be performed so that the optical path length to the lens 10 is constant. The lens 10 has a fixed focal length and is moved in the optical axis direction during zooming. In the CCD sensor 11, one pixel of the document corresponds to one element of the CCD sensor. CCD
The output of the sensor 11 is output to an A / D converter. First and second carriages 7, 9 and mirror 12
The movements of a and 12b are each performed by a stepping motor (not shown). The first and second carriages 7 and 9 are used for the operation of a timing belt (not shown) suspended between a drive pulley (not shown) and an idle pulley (not shown) connected to the rotation shaft of the stepping motor. It will be moved accordingly. The spiral shaft (not shown) of the lens 10 is rotated by a corresponding stepping motor (not shown), and is moved in the optical axis direction by the movement of the spiral.

Numeral 60 denotes a laser diode, which corresponds to the collimator lens 62, polygon mirror (polyhedral reflecting mirror) 64, lens 66, and reflecting mirror 6 corresponding to the laser diode 60.
The exposure device 52 irradiates the photosensitive drum 50 with a laser beam.

The printer 3 combines, for example, a laser optical system and an electrophotographic system capable of forming an image on transfer paper. That is, the printer 3 includes a photosensitive drum 50 as an image carrier rotatably supported at a substantially central portion in the apparatus.
The exposure device 5 is provided around the photosensitive drum 50.
2, a developing device 54, a transfer charger 55, a peeling charger 56, a PCC charger 57, a static elimination lamp 58, and a charging charger 59 are arranged in this order. The photosensitive drum 50 is configured to be uniformly charged by the charging charger 59, and outputs a laser beam from the scanner 2 to form an image of a document on the photosensitive drum 50, thereby forming an electrostatic latent image. An image is formed.

The electrostatic latent image formed on the photosensitive drum 50 is developed by a developing device 54 and fed from a paper feed cassette 30 as a paper feeding means to be described later.
0, a copy fed through the aligning roller 25
The developed image is transferred onto the paper P by the transfer charger 55. The copy paper P transferred by the transfer charger 55 is separated by the separation charger 56 by the AC corona discharge, and is conveyed to the fixing device 71 via the conveyance belt, and the developed image is fused and fixed by the fixing device 71. The copy paper P is discharged from the discharge tray 7 by the discharge roller pair 73.
4a. Unit 74
Has a roller pair 74b that faces down the copy paper P discharged from the paper discharge roller pair 73,
A stapler 74c for stapling one copy at a time in the staple sort mode is provided at the upper part of the stapler 74.

On the other hand, the developer remaining on the photosensitive drum 50 after the transfer and peeling of the developed image onto the copy paper P is
The cleaning is performed by the PCC charger 57, and the potential on the photosensitive drum 50 is reduced to a certain level or less by the charge removing charger 58, thereby enabling the next copy operation.

In the case of a double-sided copy for printing on both sides of the copy paper P, the copy paper P on which the developed image has been fused and fixed by the above-described fixing device 71 is transported via the transport path 75a. , Are accumulated in the tray 75b. The single-sided printed paper P stored in the tray 75b is transferred to the transport path 7
5c to the transfer charger 55 described above,
The developed image is transferred to the other side not printed. A light reflection type paper sensor 75 is provided below the tray 75b.
d is provided, and the presence or absence of sheets stacked on the tray 75b is detected.

Further, the transport path 75a, the tray 75b, the transport path 75c, and the paper sensor 75d constitute an automatic duplexing device (ADD) 75 as an automatic duplex reversing mechanism. In the figure, reference numeral 30 denotes a paper feed cassette as a paper feeding means which is detachably mounted on a plurality of upper and lower stages from the front side of the apparatus main body 1. The paper feed cassette 30 is composed of a cassette case 31 which is a housing in which copy paper P is stored, and has a configuration in which a take-out end of the cassette case 31 is inclined in a paper take-out direction. The copy paper P stored in the cassette case 31 of the paper feed cassette 30 is picked up by the pickup roller 81 from the uppermost layer and taken out. The copy paper P taken out by the pickup roller 81 and fed to the take-out end of the cassette case 31 is fed to a paper feed roller 84 and a separation roller ( Alternatively, the sheet is separated one by one by a sheet separation unit including a separation pad (85) and transported to the printer 3.

Next, a control system of the digital copying machine 1 will be described with reference to FIGS. 2 shows the overall configuration of the control system of the digital copying machine 1 having a facsimile function and a printer function. FIG. 3 shows the scanner 2, FIG. 4 shows the system unit 311, FIG. 5 shows the printer 3, and FIG.
12 is shown.

The control system of the digital copying machine 1 is generally composed of two blocks. The image processing unit 314 connects the scanner 2 and the printer 3 with each other, and the digital copier 1 has a facsimile (FAX) 312 as a facsimile function. A basic unit 301 constituting the copying machine 1 and the basic unit 30
Page memory unit 302 as a storage unit for realizing a memory copy by receiving and storing the image data from No. 1 and transferring the stored image data to the basic unit 301 again.
It is composed of

The basic unit 301 and the page memory unit 302 are connected by a basic unit system interface 316 for exchanging control data and a basic unit image interface 317 for exchanging image data.

Next, the basic unit 301 includes a scanner 2 as an input unit, a printer 3 as an output unit, an image processing unit (image processing unit) 314, a facsimile 312, and a control unit (system unit) 311 for controlling these units. Be composed.

Control means (system part) as shown in FIG.
The ISA bus 330 is provided to the system CPU 311.
, A main memory (RAM) 104 as a storage means, an image memory 106, a timer memory 1
08, a PIN code memory 110, a timer 112, an internal interface 122, a unit 74, a facsimile interface (FAX I / F) 331, a printer interface (printer I / F) 332, and an extension interface (EX I / F) 333. Have been.

A control panel 114 is connected to the internal interface 122.
, A message display 93, a numeric keypad 105, a start key 101 and the like are arranged.

Facsimile interface (FAX I
/ F) 331 is connected to a telephone line, a printer interface (printer I / F) 332 is connected to a personal computer (not shown), and an external device interface (EX I / F) 333 is connected to additional equipment (not shown).

The system CPU 100 is connected to an engine CPU 190 and a facsimile (FAX) 312. The engine CPU 190 controls the scanner 2 and the printer 3. further,
As will be described in detail later, the system CPU 1 as control means
00 incorporates a DMA controller 100a and a memory controller 100b.

Next, a detailed configuration of the scanner 2 will be described with reference to FIG. The engine CPU 190 is a lamp control unit 1 that controls the exposure lamp 6 in the scanner 2.
64, a motor driver 16 for controlling the scanning motor 166
8. A sensor including a document size detection sensor 169, a switch, and a driving unit 172 for driving and controlling the solenoids 170 are connected to and controlled by a driving unit 172.
An A / D conversion circuit 176, a resolution conversion circuit 178, a shading correction circuit 179, an image quality improvement circuit 180, and a binarization circuit 182 for image processing of image information from the D sensor 11 are connected and controlled.

Next, the printer 3 will be described in detail with reference to FIG. The engine CPU 190 controls a main motor driver 194 for driving the main motor 192 of the printer 3, a sensor including a paper size detection sensor 195, a switch, a driving unit 198 for driving and controlling solenoids 196, and a fixing lamp 200 of the fixing unit 71. Lamp controller 202, charging charger 59, transfer charger 55, peeling charger 56, PCC charger 5
7, a high-voltage output control unit 212 for controlling the discharge roller 58, a discharge lamp control unit 216 for controlling the discharge lamp 58, a feed control unit 224 for controlling the feed roller 222, a feed motor 222 for the pickup roller 81, the laser diode 60, and A modulation circuit 232 for controlling the laser drive circuit 230 for the polygon motor 228 is connected. Engine CPU 190
Controls each connected unit. High voltage output control section 212, charging charger 59, transfer charger 5
5, between the peeling charger 56 and the PCC charger 57, high-voltage transformers 59a, 55a, 56a,
57a are provided.

Next, the page memory unit 302 will be described with reference to FIG.
This will be described with reference to FIG. The page memory unit 302 controls access to the page memory 323 from the basic unit 301, and includes a system control unit 30 having a built-in communication memory 305.
4. Storage means for temporarily storing image data (P
M: page memory) 323, an address control unit 306 for generating an address of the page memory 323, and an image bus 3 for transferring data between devices in the page memory unit 302.
20, a control bus 321 for transferring a control signal between each device in the page memory unit 302 and the system control unit 304, and a data transfer between the page memory 323 and another device via the image bus 320. Data control means 307 for controlling data transfer; image data I for interfacing image data when transferring image data with basic unit 301 via basic unit image interface 317
/ F means 308, when transmitting image data to a device with a different resolution, converts the image data to a resolution of another device, or converts image data received from a device with a different resolution to the resolution of printer 3 of basic unit 301 Resolution conversion / binary rotation means 325 for performing 90-degree rotation processing of binary image data, for devices that compress and transmit or store image data such as facsimile transmission and optical disk storage A compression / expansion means 324 for expanding input image data or expanding image data in a compressed form for visualization printing, and image data I / F means 3
08, a multi-value rotation memory 309 used when outputting image data from the printer 3 by rotating the image data by 90 degrees or -90 degrees.

Next, the facsimile 312 will be described with reference to FIG. The facsimile 312 is connected to a telephone line, and has a modem 242 as a modem for connection to an analog line, a CODEC 244 and 246 as an encoding / decoding device for binary image data, an EPROM 248 for a communication control program, and an image ROM for image data. Pseudo SRAM 25 as storage means backed up in battery 250
2, a work RAM 254, an additional memory 256, and an interface ASIC 258 for outputting facsimile reception data to the image processing unit 314, which are used when performing various processes of image data.

FIG. 7 shows the structure of the control panel 114. That is, the control panel 11
Reference numeral 4 denotes a finisher key 82, a status indicator 83, and a cassette selection key 8 as means for selecting the sheet cassette 30.
6, HELP key 87, automatic paper selection key 88, automatic magnification selection key 89, zoom / 100% key 90, original size key 91, paper size key 92, message display 9
3, automatic density key 94, manual density key 95, preheat key 96, interrupt key 97, all clear key 98,
It comprises a clear / stop key 99, a start key 101, a timer key 103, a numeric keypad 105, and a communication start key 120.

The finisher key 82 is used to select a sort mode, a group mode, or a staple mode. The display panel 83 blinks and displays various pictograms to indicate the state of the copying machine.

When the selected cassette is not the desired size, the cassette selection key 86 can be pressed to select another cassette. HELP key 87
When pressed as an operation guide key, a message indicating the operation procedure is displayed, and when pressed after setting the function, the settings can be confirmed.

The automatic paper selection key 88 is normally in the automatic paper selection mode. The size of the document set on the platen (glass) 5 is automatically detected, and a sheet of the same size is automatically selected (only the same size copy).

When an automatic magnification selection key 89 is pressed to select an automatic magnification selection mode and specify a desired paper size, the size of the original set on the original platen (glass) 5 is detected, and the copy magnification is automatically set. Is calculated.

The zoom / 100% key 90 is "25%
When the <> key is pressed, the copy magnification is reduced to 25% in increments of 1%. When the “> 800%” key is pressed, the copy magnification increases to 800% in increments of 1%. "100
Press the "%" key to return to the same size (100%).

The document size key 91 is used to set a document size. When the paper size is selected and the document size is specified, the copy magnification is automatically set.
The paper size key 92 is used to select a paper size.

The message display 93 displays the state of the digital copying machine 1, the operation procedure, and various instructions to the user in characters and pictures. The message display 93 as a display means has a built-in touch panel, and can set functions.

When the automatic density key 94 is selected, the digital copying machine 1 automatically detects the density of the original and selects the optimum copy density. Manual density key 95
In the manual density, a desired copy density can be selected. The density can be reduced in five steps by pressing the "light" key, and the density can be reduced in five steps by pressing the "dark" key.

When this key is pressed, the preheating key 96 enters a preheating (power saving) state and all the display lamps are turned off. To make another copy, press this button again. The interrupt key 97 is used to make an interrupt copy during continuous copying.

When the all clear key 98 is pressed, all the selected modes are cleared and the mode returns to the standard state. The clear / stop key 99 is used to correct the number of copies or to stop the copy operation.

The start key 101 is pressed to start copying. When this key is pressed, the timer key 103
At what time the digital copier 1 is turned on and off is displayed (when a weekly timer is set).

The numeric keypad 105 is used to set the number of copies to be made. The number of copies can be set from 1 to 999. The communication start key 120 is a key for instructing the start of transmission in facsimile communication.

FIG. 8 shows the configuration of the system section 311 and peripheral components in the digital copying machine 1. That is,
In the digital copying machine 1, a system unit 311 having a facsimile interface 331, a printer interface 332, and an extension interface 333 for controlling data input / output is a system CPU 100, which is an embedded high-speed CPU including a DMA controller 100a and a memory controller 100b. Is configured in the core, and each interface 331, 332, 333 has expandability,
It is controlled via a versatile ISA bus 330.

The ISA bus 330 standardizes in detail the operation of an address bus, a data bus, and each control signal on the basis of an 8.3 MHz bus clock, and the interfaces 331, 332, and 333 have specifications conforming to the standard. Designed with. Therefore, the system clock (33MH)
z), there is a large difference in the access timing between the system CPU 100 and the interfaces 331, 332, 333 of the ISA specification.
The DMA transfer control of each interface 331, 332, 333 is impossible with the built-in DMA controller 100a.

Therefore, in the present invention, the access (DMA) of the system CPU with high performance and the access (DMA) of each interface with low performance are performed.
An external controller and a buffer are provided in the conversion unit of the ISA bus in order to separate the data. For example, when performing a DMA transfer between an interface and a main memory controlled by a memory controller with a built-in system CPU, data of an interface transferred according to a low-speed ISA bus standard is used.
The data transfer of the main memory is completed before the transfer of the interface is completed due to the high-speed processing of the built-in memory controller and the setting of the cycle number of the built-in DMA controller. Therefore, DM between interface and main memory
A transfer is not controlled by the DMA controller and the memory controller built into the system CPU, but an external controller and a buffer are provided between the interface and the main memory independent of the DMA transfer of the CPU. DMA transfer is divided into inter-frame transfer, interface-buffer transfer is controlled by an external controller, and buffer-main memory transfer is controlled by a system CPU built-in DMA controller.

FIG. 9 shows the ISA bus 330 as described above.
An external controller 340 as a data transfer control unit and a buffer 34 as a data storage unit in the conversion unit
1 shows the configuration of a system unit 311 provided with 1, 342, and 343.

That is, an external controller 340 is connected to the DMA controller 100a built in the system CPU 100, and the transfer of the facsimile interface 331, the printer interface 332, and the extension interface 333 is controlled by the external controller 340. The transfer direction is determined in advance by the external controller 3.
The flag is set in a register 340a in the memory 40.

A buffer 341 is provided between the main memory 104 and the facsimile interface 331, and the main memory 104 and the printer interface 33 are provided.
A buffer 342 is provided between the main memory 1
04 and the extension interface 333 between the buffer 34
3 are provided.

Next, the operation of DMA transfer in such a configuration will be described with reference to the flowchart of FIG. First, a write cycle will be described.

First, the system CPU 100 includes the facsimile interface 331 and the printer interface 3
32, the extension interface 333 is allocated to the DMA channel (ST1), and the DMA transfer direction (write direction) is set in the register 340a in the external controller 340 (ST2).

When the external controller 340 detects that the DMA request signal (DREQ) of the interface (331, 332, or 333) has been asserted (ST3), the write cycle starts from the setting of the control register 340a. (ST4). Here, the external controller 340 transmits the DMA request signal (DREQ0) of the facsimile interface 331.
Is detected to be asserted.

The external controller 340 is connected to the system CP
A DMA request signal (DREQ) is asserted to U100 (ST5), and D100 from system CPU 100 is asserted.
It is detected that the MA acknowledge signal (DACK) is asserted (ST6), but the DMA acknowledge signal (DACK) is sent to the facsimile interface 331.
0) is not asserted.

The DMA controller 100a and the memory controller 1 built in the system CPU 100
00b under control of the main memory 104 → buffer 34
DMA transfer of data is performed between the two (ST7).

The external controller 340 controls the buffer 341
(ST6) when it is recognized that the transfer to the CPU has been completed (the system CPU 100 has become inactive in DACK).
The control of the DMA controller 100a and the memory controller 100b built in the system CPU 100 is changed to the control of the external controller 340.

Here, a DMA acknowledge signal (DACK0) and a write command are asserted from the external controller 340 to the facsimile interface 331 (ST8), and DMA transfer of data between the buffer 341 and the facsimile interface 331 is performed (ST).
10). At this time, the system CPU 100 can perform other processing regardless of the DMA transfer.

The DM of the facsimile interface 331
When the A request signal (DREQ0) becomes inactive (ST9), the facsimile interface 331
DMA transfer of data to the memory is completed (ST11).

Next, the read cycle will be described.
The system CPU 100 allocates a facsimile interface 331, a printer interface 332, and an extension interface 333 to a DMA channel (ST1),
The external controller 34 sets the DMA transfer direction (read direction).
It is set in the register 340a within 0 (ST2).

When the external controller 340 detects that the DMA request signal (DREQ) of the interface (331, 332, or 333) has been asserted (ST3), the read cycle starts from the setting of the control register 340a. (ST4). Here, the external controller 340 transmits the DMA request signal (DREQ0) of the facsimile interface 331.
Is detected to be asserted.

The external controller 340 asserts a DMA acknowledge signal (DACK0) and a read command to the facsimile interface 331 (ST).
12). At this time, the external controller 340 sends a DMA request signal (DRE) to the system CPU 100.
Do not assert Q).

The facsimile interface 331 → buffer 34 is controlled by the external controller 340.
DMA transfer of data is performed between the two (ST14). At this time, the system CPU 100 can perform other processing regardless of the DMA transfer.

When the DMA transfer of the data to the buffer 341 is completed (the facsimile interface 331 becomes inactive DREQ) (ST13), the external controller 340 sends the DM to the system CPU 100.
A request signal (DREQ) is asserted (ST1
5) It is detected that the DMA acknowledge signal (DACK) from the system CPU 100 has been asserted (S).
T16). Now, from the control of the external controller 340,
The control is changed to the control of the DMA controller 100a and the memory controller 100b built in the system CPU 100.

DMA built in system CPU 100
Under the control of the controller 100a and the memory controller 100b, DMA transfer of data is performed between the buffer 341 and the main memory 104 (ST17).

When the DMA acknowledge signal (DACK) of the system CPU 100 becomes inactive (ST16), the DM of the data to the main memory 104 is transmitted.
The A transfer ends (ST11).

As described above, according to the embodiment of the present invention, the DM between devices having different performances
Since the A transfer is separated into high-speed transfer and low-speed transfer by an external controller and buffer, the DMA transfer of a device with low performance such as an interface of the ISA specification also differs from the CPU performance based on the system clock by the external controller and buffer. And the transfer can be completed within the DMA cycle of the controller with a built-in CPU.

In the DMA transfer between the external controller and the buffer, the DMA controller between the device and the buffer having a low performance is controlled by the external controller. Will be controlled. Therefore, differences in performance can be absorbed by the buffer, and transfer from a device of the ISA specification within a high-speed DMA cycle of the controller with a built-in CPU becomes possible.

Also, DMA transfer is performed via an external controller and a buffer, and a device with low performance
In the DMA transfer between the buffers, the external controller performs the output control of the DMA request signal, the DMA acknowledge signal, the read / write command to the device, and the like according to the transfer direction set in the internal control register. Thus, high-speed DMA transfer control with the buffer is performed. Therefore, differences in performance can be absorbed by buffers, and ISA
By passing a buffer from a device of the specification, it is possible to transfer data within a DMA cycle of a controller with a built-in CPU.

Further, when the buffer and the external controller intervene in the DMA transfer, the external controller controls the low-speed transfer between the I / O-buffer according to the low-speed ISA specification, and the DMA controller with a built-in high-speed CPU uses the memory controller.
Since only high-speed transfer between buffers is handled, DMA transfer data can be transferred within a high-speed DMA cycle by passing through the buffer once.

[0080]

As described in detail above, according to the present invention,
It is possible to provide an image forming apparatus and a data transfer method of the image forming apparatus, which are capable of performing DMA transfer between an external I / O having low performance and a memory controlled by a memory controller with a built-in high-speed CPU to achieve high-speed performance. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a digital copying machine according to an image forming apparatus of the present invention.

FIG. 2 is a system configuration diagram of the image forming apparatus.

FIG. 3 is a block diagram illustrating a configuration of a scanner.

FIG. 4 is a block diagram showing a configuration of a system unit.

FIG. 5 is a block diagram illustrating a configuration of a printer.

FIG. 6 is a block diagram showing a configuration of a facsimile.

FIG. 7 is a diagram showing a configuration of a control panel.

FIG. 8 is a diagram illustrating a configuration of a system unit and peripheral components.

FIG. 9 is a block diagram showing a configuration of a system unit in which an external controller and a buffer are provided in a conversion unit of the ISA bus.

FIG. 10 is a flowchart for explaining the operation of DMA transfer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Digital copying machine 2 ... Scanner 3 ... Printer 100 ... System CPU 100a ... DMA controller 100b ... Memory controller 104 ... Main memory 190 ... Engine CPU 311 ... System part 312 ... Facsimile 330 ... ISA bus 331 ... Facsimile (FAX) interface 332 ... Printer interface 333 ... Extension (EX) interface 340 ... External controller 340a ... Registers 341, 342, 343 ... Buffer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G06T 1/60 H04N 1/00 107Z H04N 1/00 107 1/21 1/21 G06F 15/64 450E

Claims (12)

[Claims] 1. An image forming apparatus which has a function of transferring data by being connected to an external device and forming an image based on the transferred data, wherein the data is transferred from the external device or transferred to the external device. Storage means for temporarily storing data to be stored; first control means for controlling transfer at a first speed between the storage means and the external device; and data transferred from the storage means or the storage Storage means for storing data to be transferred to the storage means, and second control means for controlling transfer between the storage means and the storage means at a second speed higher than the first speed. An image forming apparatus comprising: 2. An image based on data transferred having first control means connected to an external device for controlling data transfer at a second speed higher than the first speed and performing overall control. A storage unit for temporarily storing data transferred from the external device or data to be transferred to the external device; and a transfer at a first speed performed between the storage unit and the external device. And a transfer control at a second speed of the first control means.
An image forming apparatus comprising: a storage unit that stores data transferred from the storage unit or data transferred to the storage unit. 3. A DMA controller connected to an external device for controlling data transfer at a second speed higher than the first speed, and a CPU having a memory control function and performing overall control and transferring the data. An image forming apparatus for forming an image based on data, comprising: a buffer for temporarily storing data transferred from the external device or data to be transferred to the external device; and a first speed performed between the buffer and the external device. An external controller for controlling the transfer of data, and a memory for storing data to be transferred from the buffer or data to be transferred to the buffer by transfer control at a second speed of the DMA controller and the memory control function of the CPU. An image forming apparatus comprising: 4. A DMA controller for controlling data transfer at a second speed higher than the first speed via an interface to which an external device is connected, and a CPU having a memory control function and performing overall control. An image forming apparatus for forming an image based on data to be transferred, a buffer for temporarily storing data transferred from the interface or data to be transferred to the interface, and a first buffer between the buffer and the interface. An external controller that controls transfer at a high speed, a DMA controller included in the CPU, and transfer control at a second speed of a memory control function, which stores data transferred from the buffer or data transferred to the buffer. An image forming apparatus, comprising: a memory; 5. An image forming apparatus connected to an external device for transferring data and forming an image based on the transferred data, wherein the data transferred from the external device is transmitted at a first speed. First control means for performing transfer control; storage means for temporarily storing data to be transfer-controlled by the first control means; and data stored in the storage means at a second speed higher than the first speed. An image forming apparatus comprising: a second control unit for performing transfer control; and a storage unit for storing data to be transferred and controlled by the second control unit. 6. An image forming apparatus which has a function of transferring data by being connected to an external device and forming an image based on the transferred data, a storage means for storing the data to be transferred, and First control means for controlling transfer of stored data at a first speed, storage means for temporarily storing data to be transfer-controlled by the first control means, and data stored in the storage means First to the above external equipment
And a second control unit that performs transfer control at a second speed lower than the speed of the image forming apparatus. 7. A data transfer method for an image forming apparatus having a function of transferring data by being connected to an external device and forming an image based on the transferred data, the data being transferred from the external device. Wherein the data to be transferred to an external device is controlled separately from transfer at a first speed and transfer at a second speed higher than the first speed. Transfer method. 8. Based on data transferred having first control means connected to an external device and controlling data transfer, and second control means controlling data transfer and performing overall control. A data transfer method of an image forming apparatus for forming an image, wherein data transferred from the external device or data to be transferred to the external device is transfer-controlled at a first speed by the first control means, and 2. A data transfer method for an image forming apparatus, wherein transfer control is performed at a second speed higher than the first speed by the second control means. 9. A DMA controller connected to an external device for controlling data transfer at a second speed higher than the first speed, and a CPU having a memory control function and performing overall control and transferring the data. A data transfer method for an image forming apparatus that forms an image based on data, comprising: transferring data transferred from the external device or data transferred to the external device at a first speed and temporarily storing the data;
A data transfer method for an image forming apparatus, wherein transfer of temporarily stored data or data to be temporarily stored is controlled at a second speed by a DMA controller and a memory control function of the CPU. 10. A DMA controller for controlling data transfer at a second speed higher than the first speed via an interface to which an external device is connected, and a CPU having a memory control function and performing overall control. A data transfer method of an image forming apparatus for forming an image based on transferred data, wherein data transferred from the interface or data transferred to the interface is transferred at a first speed and temporarily stored, A data transfer method for an image forming apparatus, wherein transfer of stored data or temporarily stored data is controlled at a second speed by a DMA controller and a memory control function of the CPU. 11. A data transfer method for an image forming apparatus which has a function of transferring data by being connected to an external device and forms an image based on the transferred data, wherein the data transferred from the external device is provided. Transfer control of the image forming apparatus at a first speed to temporarily store the data, and transfer control of the stored data at a second speed higher than the first speed to store the stored data. Method. 12. A data transfer method for an image forming apparatus which has a function of transferring data by being connected to an external device and forms an image based on the transferred data, the method comprising: A data transfer method for an image forming apparatus, wherein transfer control is performed at a second speed to temporarily store the data, and transfer of the stored data to the external device is performed at a second speed lower than the first speed.