Abstract:
To design an integrated circuit device, i.e., a main ASIC, that can easily be used for both communications and image data processing. To use the ASIC for the purpose of image data processing, the ASIC is set to a first operation mode, wherein a printer engine and a laser scanner are controlled via a printer engine controller and laser scanner controller. To use the ASIC for the purpose of communications, it is set to a second operation mode, wherein communications data is received from a remote device connected to a network chip via a network. In this manner, the ASICs with the same hardware configuration can be used in different purposes while switching operation modes.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to integrated circuit devices capable of controlling an image data processing device and a network connection device.  
           [0003]    2. Description of the Related Art  
           [0004]    Printers and other image forming devices can be connected to the Internet, LAN and other networks and be used to form images from data received via such networks. Japanese Patent Application Publication No. 11-53139 proposes equipping two separate sets of integrated circuit devices to such an image forming device, one for mainly performing communications and another for mainly performing image formations. Such a configuration would enable parallel processing and improve processing speed.  
           [0005]    A recent trend in semiconductor technology is to use an ASIC (Application Specific Integrated Circuit) in which integrated are a CPU and a hardware (ports, buses and controllers that control the ports and the buses) connected to the CPU. ASIC simplifies control board manufacture and improves manufacturing efficiency of image forming devices.  
           [0006]    However, when the integrated circuit devices used specifically for communications and those used specifically for image formation coexist, as described above, the communications ASIC and the image forming ASIC need to be separately designed. The same problem also applies to scanners that scan images concurrently with performing communication tasks.  
         SUMMARY OF THE INVENTION  
         [0007]    In view of the foregoing, it is an object of the invention to provide an integrated circuit device that can be commonly used for both communications and image formation.  
           [0008]    To achieve the above and other object, there is provided an integrated circuit device that includes a first terminal portion, a second terminal portion, a third terminal portion, an operation mode setting device, and a processing device. The integrated circuit device has such a structure that one of a first external device and a second external device is selectively connectable to the first terminal portion, one of a third external device and a fourth external device is selectively connectable to a second terminal portion, and an image forming device is connectable to the third terminal portion. The operation mode setting device sets the integrated circuit device to either a first operation mode or a second operation mode. The processing device controls the first terminal portion, the second terminal portion and the third terminal portion, and further controls data transmission/reception via each of the first terminal portion, the second terminal portion and the third terminal portion. When at least one of the first external device and the third external device is connected to relevant terminal portion, the first operation mode is set by the operation mode setting device. In this case, the processing device controls the image forming device connected to the third terminal portion to form images based on data supplied from one of the first external device and the third external device. On the other hand, when the second external device is connected to the first terminal portion, the second operation mode is set by the operation mode setting device. In this case, the processing device controls the first terminal portion to perform transmission/reception of first data to and from the second external device. When the second external device is connected to the first terminal portion and the fourth external device is connected to the second terminal portion, the second operation mode is set by the operation mode setting device. In this case, the processing device controls the first terminal portion to perform transmission/reception of the first data to and from the second external device and also controls the second terminal portion to perform transmission/reception of second data to and from the fourth external device. The second data corresponds to the first data.  
           [0009]    According to another aspect of the invention, there is provided a communication interface device that includes a first terminal portion, a second terminal portion, and a processing device. A network chip is connected to the first terminal portion and an image data processing device is connected to the second terminal portion. The processing device controls the first terminal portion and the second terminal portion, and further controls data transmission/reception via each of the first terminal portion and the second terminal portion. The processing device controls the first terminal portion to upload/download first data to and from a remote device connected to the network chip via a network, and also controls the second terminal portion to perform transmission/reception of second data to and from the image data processing device. The second data corresponds to the first data.  
           [0010]    According to still another aspect of the invention, there is provided an image data processing device that includes a first integrated circuit device. The image data processing device may further include a second integrated circuit. The first integrated circuit device includes a first terminal portion to which a first external device is connected, a second terminal portion to which a second external device is connected, a third terminal portion to which an image forming device is connected, and a first processing device. The first processing device controls the first terminal portion and the second terminal portion and further controls data transmission/reception via each of the first terminal portion, the second terminal portion and the third terminal portion. The first processing device controls the image forming device to form images based on data supplied from the at least one of the first external device and the second external device.  
           [0011]    The second integrated circuit device is identical in a hardware structure to the first integrated circuit device but can be used in different purposes. The second integrated circuit device includes a fourth terminal portion corresponding to the first terminal portion, to which a network chip is connected, a fifth terminal portion corresponding to the second terminal portion, to which the first integrated circuit device is connected, and a second processing device. The second processing device controls the fourth terminal portion and the fifth terminal portion, and further controls data transmission/reception via each of the fourth terminal portion and the fifth terminal portion. The second processing device controls the fourth terminal portion to upload/download first data to, and from a remote device connected to the network chip via a network, and also controls the fifth terminal portion to perform transmission/reception of second data to and from th first integrated circuit device. The second data corresponds to the first data. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    In the drawings:  
         [0013]    [0013]FIG. 1 is a block diagram showing a configuration of a printer in accordance with an embodiment of the present invention;  
         [0014]    [0014]FIG. 2 is a block diagram showing a configuration of a main ASIC incorporated in the printer shown in FIG. 1;  
         [0015]    [0015]FIG. 3 is a block diagram showing a configuration of a printer in accordance with a first modification of the embodiment shown in FIG. 1;  
         [0016]    [0016]FIG. 4 is a block diagram showing a configuration of a printer in accordance with a second modification of the embodiment shown in FIG. 1; and  
         [0017]    [0017]FIG. 5 is a block diagram showing a configuration of a printer in accordance with a third modification of the embodiment shown in FIG. 1. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0018]    Preferred embodiments of the invention will be described while referring to the accompanying drawings. FIG. 1 is a block diagram showing a configuration of a so-called network printer to which the present invention is applied. In use, the network printer is connected to the Internet, LAN or other network and capable of receiving data via the networks and printing images based on the data received.  
         [0019]    As shown in FIG. 1, the printer in this embodiment includes an image data processing board serving as a main controller  1 , and a communications interface board serving as a network printed circuit board  2  (hereinafter referred to as “network PCB  2 ”). Note that the network PCB  2  is provided as an option so it can be removed if unnecessary.  
         [0020]    The main controller  1  includes an IEEE1284 port  4  that can be connected to a personal computer (PC)  3   a  using a parallel cable, a USB port  5  that can be connected to a PC  3   b  using a USB cable, and a modem  7  that is connected to the telephone lines via an NCU (network control unit)  6  to enable facsimile communication.  
         [0021]    The main controller  1  further includes an integrated circuit device in the form of a main application-specific integrated circuit (ASIC) BA containing a CPU  80  (to be described later). The main ASIC  8 A governs the operations of the main controller  1  together with a sub ASIC  15  to be described later. Connected to the main ASIC  8 A are the IEEE1284 port  4 , the USB port  5 , a printer engine  11  for forming images on a print paper (not shown), a laser scanner  12  for forming an electrostatic latent image on a photosensitive drum (not shown) provided in the printer engine  11 , and an operation panel  13 .  
         [0022]    The sub ASIC  15  is connected to the main ASIC  8 A via a PCI bus  14   a.  Also, a ROM  18 , a RAM  19  and the modem  7  are connected via an external system bus  17   b  to the main ASIC  8 A. The sub ASIC  15  controls a document scanner  20  that scans document images and transfers the corresponding image data to the sub ASIC  15 . The ROM  18  stores an image forming program that drives and controls the printer engine  11  and other devices.  
         [0023]    The network PCB  2  also includes a main ASIC  8 B that is identical to the main ASIC  8 A provided in the main controller  1 . A PCI bus  14   b  connects the main ASIC  8 B to a network chip  21  that serves as a communication device, while an external system bus  17   c  connects the main ASIC  8 B to a ROM  23  and a RAM  24 . The network PCB  2  is equipped with a network port  25  to connect the network PCB  2  to the above-mentioned network. The main ASIC  8 B communicates with the network via the network chip  21  and the network port  25 . Furthermore, the main ASIC  8 B in the network PCB  2  is directly connected to the external system bus  17   b  of the main controller  1  via a control parallel bus  30 . The ROM  23  stores a communications program used by the network.  
         [0024]    Next, the configuration of the main ASIC  8 A will be described in detail while referring to FIG. 2. Note that the configuration of the main ASIC  8 B provided in the network PCB  2  is identical to that of the main ASIC  8 A. As shown in FIG. 2, the CPU  80  is connected to an internal system bus  17   a  via a system bus controller  81 . The internal system bus  17   a  and the external system bus  17   b  will be referred collectively to as “system bus  17 ” provided that there are no distinctions therebetween in terms of signals passing therethrough and functions of the two buses. Connected to the internal system bus  17   a  are a DMA controller  82 , an SRAM  83 , the printer engine controller  84 , a laser scanner controller  85 , a panel controller  86 , a PCI bus controller  87 , and a USB controller  88 . The printer engine controller  84  has a port to which the printer engine  11  is connectable. Likewise, the laser scanner controller  85  has a port to which the laser scanner  12  is connectable. The panel controller  86  has a port to which an operation panel  13  is connectable. The PCI bus controller  87  has a port to which the PCI bus  14   a  is connectable.  
         [0025]    The internal system bus  17   a  is connected to a pin selector controller  92  via a second bus controller  91  and an IEEE1284 controller  92 . A mode select signal input to a mode select terminal  8   a  provided on the housing of the main ASIC  8  switches a flip-flop (F/F)  94 . The output of the flip-flop  94  determines whether the pin selector controller  92  connects the second bus controller  91  or the IEEE1284 controller  93  to a pin  92   a  (only one pin is shown in the figure, but actually there are multiple pins that are provided on a bit basis for multi-bit data output from the pin selector controller  92 ). The SRAM  83  is connected to an SRAM controller  95  that switches connections depending on the output of the flip-flop  94 . The output of the flip-flop  94  determines whether the SRAM controller  95  connects the SRAM  83  to the second bus controller  91  or to the laser scanner controller  85 .  
         [0026]    When the mode select signal input to the mode select terminal  8   a  indicates a first operation mode, the main ASIC  8 A operates to receive image data from the PC  3   a  and print images based on the image data received. Specifically, in the first operation mode, the pin selector controller  92  is switched to the IEEE1284 controller  93  and the SRAM controller  95  is switched to the laser scanner controller  85 . Then the pin  92   a  is connected to the IEEE1284 port  4  enabling reception of the image data from the PC  3   a.  The image data received therefrom is temporarily stored in the SRAM  83  serving as a buffer and printed by the printer engine  11  and the laser scanner  12 .  
         [0027]    When the mode select signal input to the mode select terminal  8   a  indicates a second operation mode, the main ASIC  8 A cooperates with the network PCB  2 . Specifically, in the second operation mode, the pin selector controller  92  is switched to the second bus controller  91  and the SRAM controller  95  is also switched to the second bus controller  91 . Then the pin  92   a  is connected to the second bus  30 . In this state, data can be sent to the main controller  1  from the network PCB  2  via the second bus  30 . The SRAM  83  is then used as a FIFO (First-In First-Out) memory to store the data transferred from the network PCB  2 .  
         [0028]    The CPU  80  provided in the main ASIC  8 B of the network PCB  2  converts data received via the network chip  21  to intermediate code for image data, and directly transfers the resulting data to the system bus  17  of the main controller  1  via the second bus  30 . The CPU  80  provided in the main ASIC  8 A of the main controller  1  converts the intermediate code to dot data to control the printer engine  11  and the laser scanner  12 .  
         [0029]    The CPU  80  in the main controller  1  performs the following tasks: Copying of the original image read by the document scanner  20  with the printer engine  11  and laser scanner  12 ; FAX reception of facsimile data received via the modem  7 ; FAX transmission of original image read by the document scanner  20  that is sent as facsimile data via modem  7 ; Printing of images based on image data received from the PC  3   a  via the IEEE1284 port  4  or received from the PC  3   b  via the USB port  5 .  
         [0030]    As described above, the CPUs  80  in the main ASICs  8 A and  8 B execute different functions due to different programs stored in the ROMs  23  and  18 . The program may contain hardware requirements dictating which port, bus or controller CPU  80  should be connected to and these requirements must be met to ensure smooth program operation. Since the ports in this embodiment are switched according to operation mode as described above, the main ASIC  8 A is capable of performing the two types of operation described above.  
         [0031]    The use of the same main ASIC  8  for image data processing and communications simplifies both the design and assessment of the control system and reduces printer manufacturing costs. In this embodiment, the second bus  30  is directly connected to the system bus  17  of the main controller  1 . This makes the main ASIC  8 A free from transmission/reception of the image data to and from the second bus  30 , allowing the main ASIC  8 A to concentrate on image forming operation. Not only does this allow parallel processing of communications and image forming operation, but speeds up image forming operation.  
         [0032]    According to the embodiment described, the connection of the SRAM  83  is switched depending on the operation mode, thereby enabling highly efficient use of the SRAM  83  both in communications and image forming operations.  
         [0033]    While the preferred embodiment of the invention has been illustrated and described, it will be appreciated for a person skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. For example, as shown in FIG. 3, the network PCB  2  and its associated second bus  30  may be removed to use the main controller  1  and its associated components as a facsimile device and a PC printer. Also in this case, copying function, FAX reception function, FAX transmission function and PC printing function can be achieved as described above. As shown in FIG. 4, the modem  7 , the document scanner  20  and the sub ASIC  15  may be removed to use the device as a PC printer.  
         [0034]    As shown in FIG. 5, the configuration shown in FIG. 4 may further be modified to connect a network chip  21  to the PCI bus controller  87  (see FIG. 2) of the main ASIC  8 A via the PCI bus  14  and to connect a network port  25  to the network chip  21 . Then the device shown in FIG. 5 can be used as a network printer capable of forming images based on data received via the network. In this case, the ROM  18  must store a network communications program. Although the single CPU  80  will be used in time sharing manner to perform both communications and image forming processes, the use of a versatile main ASIC  8 A for both communications and image processing lowers costs. The main ASIC  8 A in this case is placed in the first operation mode. The main ASIC  8 A does not transmit data via the second bus  30  and therefore need not be placed in the second operation mode. Thus the use of one ASIC  8 A can implement four types of image forming devices as shown in FIGS. 1, 3,  4  and  5 , simplify design of the control system, and reduce the cost of the image forming device.  
         [0035]    In the main ASIC  8 A in the above-described embodiment, the pin selector controller  92  selectively connects the pin  92   a  to the second bus controller  91  or the IEEE1284 controller  93 . However, a set of pins for connection to the second bus controller  91  and another set of pins for connection to the IEEE1284 controller  93  could both be located on the periphery of the main ASIC  8 A. With such a configuration, the mode switching described above could be performed depending on which set of pins is connected to the external circuit. This would make it possible to further simplify internal ASIC  8 A design and lower manufacturing costs. On the other hand, provision of only one set of pins as in the described embodiment reduces the number of pins around the main ASIC  8 A and makes it more compact.  
         [0036]    Furthermore, the first and second buses can be used for miscellaneous other functions. However, since the above described embodiment uses the PCI bus  14  as the first bus, data transmission via the PCI bus  14  is extremely quick, so that the above-described processes can be implemented at a high speed. The invention can be applied to image data processing devices that are equipped with only the document scanner  20 .  
         [0037]    This invention can be applied to devices that use a communications board as the main controller and use an image data processing board as an option. The CPU  80  does not need to be a part of the integrated circuit but can be supplied from outside via the external system bus.