JPH04248590A - Data transfer equipment - Google Patents

Abstract

PURPOSE:To offer a data transfer equipment which can display bit map data, specially, in the control of window system and can be utilized for transfer control over moving picture data as for the transfer device for still and moving picture data. CONSTITUTION:The data transfer equipment is equipped with an address generating means 11 which generates corresponding memory addresses according to two-dimensional rectangular coordinate values, a data control means 12 which controls the input and output of data, a rectangle transfer control means 13 which performs transfer flow control over data to respective means, a parameter storage means 2 stored with plural rectangle transfer parameters, and a plural- rectangle transfer control means 3 which transfers plural rectangle data in the parameter storage means by controlling the rectangle transfer means 13 or address generating means 11.

Description

Description: [0001] The present invention relates to a data transfer device for transferring still image data and moving image data, particularly for controlling bitmap data transfer under a window system. . 2. Description of the Related Art In recent years, it has become common for personal computers and workstations to implement graphical user interfaces for the purpose of improving operability. These are supported by software called window systems, allowing them to run on different machines. [0003] The characteristics of such a window system are as follows.
It is highly portable. However, the emphasis on portability led to software overhead, which slowed down the drawing processing speed. Recently, graphics processing such as line drawing has become faster due to faster CPUs, but it is slow when it comes to displaying bitmap data such as natural images, making it almost unusable when handling full-color images. To solve this problem, hardware support is essential. On the other hand, recently, there has been an active development of systems for education and training that handle not only still images but also video data (multimedia systems). These are generally realized with a system configuration as shown in FIG. 12 under a window system. Functionally, it has a separate memory dedicated to moving image data, and performs video compositing processing with frame buffer data at the time of display readout, thereby realizing moving image data display. [0005] However, this method requires high speed in the video synthesis part (for pixel-by-pixel synthesis control, a processing speed of 100 MHz or more is required for a frame buffer of 1280 x 1024 pixels, for example), and the hardware requires high speed. It is difficult to realize. Furthermore, in terms of software, there are many specialized aspects for handling moving images, such as the management of the display area of moving image data and the management of moving image memory on the window system side. Therefore, in consideration of software consistency, it is desirable that moving image data be transferred to a frame buffer and displayed in the same way as still image data. [0006] As hardware that supports high-speed display of bitmap data, there is a dedicated data transfer device (DMA [Direct Memory
[Access]) or a graphics processor. However, these current hardware have the following problems. First, many conventional DMAs only support transfer using continuous linear addresses that specify only the start address and the number of data to be transferred, and realize two-dimensional address transfer using X-Y coordinates like a window system. required CPU intervention for each line. In addition, DM supports data transfer using two-dimensional addresses of X-Y coordinates.
Even in A, there was no transfer that took clipping areas into consideration, that is, there was no support for transfer of multiple rectangular areas. As shown in FIG. 13(b), under the window system, each window is often displayed in an overlapping manner, and in the figure, when the window system (host CPU) controls data transfer to Window B, , DMA that does not support two-dimensional address transfer of X-Y coordinates requires processing instructions in the flow shown in FIG. [0009] Typically, the window system is
The clipping area of wB is calculated to obtain three area parameters. Next, line parameters for each rectangle are set for the DMA. The host CPU is D per line.
After waiting for the completion of MA transfer, the next line parameter set is sequentially controlled. Also, these steps must be repeated for three rectangles. Furthermore, even in DMA that supports transfer using two-dimensional addresses, a parameter set for each rectangle is essential, and moving image data transfer, which requires transfer control 30 times per second, is virtually impossible. [0011] On the other hand, graphics processors that exclusively perform drawing processing require writing in a dedicated program interface language, making it much more difficult to port window systems than DMAs, and are currently not widely used. . Furthermore, graphics processors support a wide range of functions such as 2D/3D graphics and data transfer, so their individual specifications are as follows:
One of the reasons why it is not used is that it does not have much of an advantage in processing speed compared to a CPU, and it is difficult to differentiate it from a CPU.
It is one. [0013] The present invention solves the above-mentioned problems, and speeds up bitmap data transfer under a window system by providing means for controlling two-dimensional address transfer of X-Y coordinates of a plurality of rectangles. With the goal. Another object of the present invention is to provide means for controlling continuous data transfer using the same parameters in addition to the above-mentioned functions, thereby making it usable for controlling the transfer of moving image data. Means for Solving the Problems In order to achieve the above object, the data transfer device of the present invention includes address generation means for generating a corresponding memory address from two-dimensional rectangular coordinate values, and data input/output means. rectangular transfer control means for controlling the data transfer flow for each of the means, parameter storage means for storing transfer parameters for a plurality of rectangles, and the rectangular transfer control means or the address generation means. The configuration includes a plurality of rectangular transfer control means for controlling and transferring a plurality of rectangular data stored in the parameter storage means. In addition to the above configuration, the data transfer device of the present invention stores a transfer mode parameter for selecting whether or not to continuously transfer multiple rectangular data in the parameter storage means, and synchronizes with an external signal. a transfer trigger generation means for generating a data transfer start trigger based on the transfer trigger; and a transfer mode determination device for controlling continuous data transfer at the timing from the transfer trigger generation means when the transfer mode parameter is a continuous transfer mode. It has a control means. Furthermore, in addition to the second configuration, the data transfer device of the present invention detects the scanning period of the transfer rectangular area from the display scanning period of the frame buffer in data transfer to the frame buffer, and also detects the scanning period of the transfer rectangular area from the display scanning period of the frame buffer. The transfer rectangular period detecting means generates a trigger signal at the end of the transfer rectangular period detecting means, and the trigger of the transfer rectangular period detecting means is output to the transfer trigger generating means to control continuous data transfer. [0018] In the above-described configuration, data transfer of a plurality of rectangles can be realized, and most of the bitmap data transfer processing of current window systems can be supported by hardware. In addition, the host CPU processing involves only batch setting of parameters for each window, and the load can be reduced to the maximum. Furthermore, continuous data transfer using the same rectangular parameter synchronized with an external signal is possible, and moving image data transfer under a window system is also possible. At this time, by detecting the scanning timing of the moving picture window portion, it is possible to control so as not to transfer data to the window while the moving picture window is being scanned, and it is possible to realize data transfer without disturbance on the screen. [Embodiment] FIG. 1, FIG. 5, and FIG. 9 show block diagrams of a data transfer device in each embodiment of the present invention, and each host C
It has a PU interface, a source for data transfer, and an interface with a destination memory. (Embodiment 1) A first embodiment of the present invention will be described below with reference to FIGS. 1 to 4. In FIG. 1, reference numeral 1 denotes a rectangular data transfer mechanism for transferring rectangular data at a two-dimensional address of X-Y coordinates;
2 is a parameter storage means for storing parameters necessary for transferring multiple rectangles, and 3 is a multiple rectangle transfer control means. Reference numerals 11 to 13 constitute the rectangular data transfer mechanism 1; 11 is address generation means for generating source and destination transfer addresses; 12 is address generation means for generating source and destination transfer addresses; , 12 is a data control means for controlling data input/output with the source and destination memories, and 13 is a rectangular transfer control means for controlling the address generation means 11 and the data control means 12 to control the transfer of one rectangular data. . The parameters stored in the parameter storage means 2 include, for example, the number of transfer rectangles and the source memory address (pSrc), as shown in FIGS. 13(a) and 13(b).
, source data width (wSrc), each rectangular coordinate value ([x1, y1l]...[x3, y3]) on the source memory side and size ([w1, h1],...[w3, h3]) destination memory address (pDst), destination data width (wDst), and each rectangular coordinate value on the destination memory side. Here, the rectangular data transfer mechanism 1 is a conventional X
- It is equivalent to DMA that supports two-dimensional address transfer of the Y coordinate, and the address generation means 11 is a circuit that sequentially calculates addresses of pixel data from two-dimensional coordinate values. The data control means 12 is a circuit that reads/writes data from and to an external memory, and in this embodiment has a data register that holds read data. The operation of the data transfer apparatus shown in FIG. 1 will be explained below using the flowchart in FIG. 2. (201) The multiple rectangle transfer control means 3 waits for a startup instruction from the host CPU. For example, the parameter storage means 2 has a register for starting processing, and the multiple rectangle transfer control means 3 makes a judgment based on the register value. If the register value is "start instruction", the process moves to the next step. (202) The plural rectangle transfer control means 3 sets the rectangle transfer control means 13 or the address generation means 11 to the
) instructs to read the rectangle parameters. The parameters are the rectangular coordinate value and size of the source, and the rectangular coordinate value of the destination. (203) Next, the plural rectangle transfer control means 3 outputs a signal for instructing data transfer to the rectangle transfer control means 13. 003
0] (204) Rectangular transfer control means 13 that received the transfer instruction
instructs the address generation means 11 to generate source and destination memory addresses based on the rectangle parameters. After the address generation is completed, the address generation means 11 outputs a generation end signal to the rectangular transfer control means 13. (205) Upon receiving the address generation end signal from the address generation means 11, the rectangular transfer control means 13 first instructs the data control means 12 to read the source data. The instruction signals are the source memory address and the access control mode (read in this case). The data control means 12 reads the data at this memory address, stores it in an internal register, and outputs a read processing end signal to the rectangular transfer control means 13. (206) Upon receiving the read processing end signal,
The rectangular transfer control means 13 instructs the data control means 12 to write data to the destination address. The data control means 12 writes the internal register data to this memory address and outputs a write processing end signal to the rectangular transfer control means 13. (207) The rectangular transfer control means 13 checks whether the transfer of rectangular data has been completed, and if the transfer has not been completed, returns to step (204), and steps (204) to (
206) data transfer is repeated. After the rectangular transfer is completed, the rectangular transfer control means 13 sends a message to the plural rectangular transfer control means 3,
Outputs the indicated rectangle data transfer end signal. The end of transfer can be determined, for example, by the address generation means 11 based on the size of each rectangle. (208) The plural rectangle transfer control means 3 receives the rectangle data transfer end signal and checks whether there is a rectangle to be transferred next. This can be determined from the number of transfer rectangles in the parameter storage means 2. If there is a transfer rectangle, increment the current rectangle number by 1 (n=n+1)
Then, the process returns to step (202). If there is no transfer rectangle, the data transfer process ends. Here, if the address generation means 11 is controlled to execute the next address calculation process while the rectangular transfer control means 13 is processing the data control means 12, address generation and data transfer can be performed. Processing can be pipelined. Furthermore, although this embodiment has been described with one data register in the data control means, it is also possible to have a plurality of data registers.
Control may also be provided such that multiple pieces of data are read out from the source memory at once and written to the destination. In this case, it is possible to speed up data transfer by batch access, such as during transfer on a general-purpose bus. It is also possible to perform shift control etc. according to destination data using this data register. Next, a system application example using the data transfer device of this embodiment will be explained. FIG. 3 shows an example in which the data transfer device of this embodiment is used in a general workstation. The data transfer device shown in FIG. 3 is connected to a main control bus called a system bus, and executes data transfer between the main storage device and the frame buffer according to instructions from the CPU. In the system shown in FIG. 3, FIG.
), the control processing of the window system becomes the flow shown in FIG. 4. The window system first calculates (1) to (3) 3 regarding Window B from the window overlap.
Compute two rectangular parameters. Next, these three rectangular parameters are set in the parameter storage means 2, and the data transfer device is instructed to start the transfer process. After that, wait for the end of data transfer. In this case, the window system does not necessarily have to wait for the end of the data transfer, and the window system can move on to the next process. Therefore, in the flow shown in FIG. 4, the load on the host CPU is significantly reduced compared to the conventional flow in the data transfer apparatus shown in FIG. According to the present embodiment, by providing means for performing data transfer using two-dimensional addresses of a plurality of rectangles as a data transfer device, it is possible to realize high-speed data transfer with reduced control processing of the window system. (Example 2) Next, the second example is shown in FIGS.
This will be explained using FIG. In FIG. 5, the rectangular data transfer mechanism 1, parameter storage means 2, and plural rectangle transfer control means 3 are as shown in FIG.
This is the same as in the embodiment, and 4 is a continuous data transfer control mechanism. 41 and 42 are continuous data transfer control mechanism 4
41 is a transfer trigger generation means for continuous data transfer, and 42 is a plural rectangular transfer control means for determining the transfer mode from the parameters in the parameter storage means 2 and using the trigger of the transfer trigger generation means 41. 3. This is a transfer mode determining means that controls the transfer mode. In addition to the parameters in the embodiment of FIG. 1, the parameter storage means 2 contains a transfer mode parameter for selecting whether or not to perform continuous transfer, and a status flag parameter indicating the operating state of the data transfer control device. and a stop flag parameter that instructs to stop continuous transfer. It is assumed that the transfer trigger generation means 41 generates the trigger from, for example, a vertical synchronization signal for continuous transfer of moving image data. The operation of the data transfer apparatus shown in FIG. 5 will be explained below using the flowchart in FIG. 6. (601) The transfer mode determining means 42 sets the status flag parameter (Sta) in the parameter storage means 2 as the initial setting of the data transfer device.
tus) to the waiting state (Ready). When performing data transfer, the window system checks this status flag parameter and issues a transfer instruction. This is to prevent the CPU from changing the transfer rectangle parameters while the data transfer device is continuously transferring data. If it is necessary to change parameters during continuous transfer, use the stop flag parameter shown below. (602) The transfer mode determining means 42 waits for an activation instruction from the host CPU. For example, the parameter storage means 2 has a register for starting processing, and the transfer mode determination means 42 makes a determination based on the register value. If the register value matches the "start instruction", the process moves to the next step. (603) Upon receiving the transfer instruction, the transfer mode determining means 42 sets the status flag parameter in the parameter storage means 2 to the processing state (Busy). (604) Next, the parameter storage means 2
It is checked whether or not the transfer is continuous based on the transfer mode parameter in , and if it is continuous transfer, the process moves to step (607); otherwise, the process moves to step (605). (605) If the transfer is not continuous, the transfer mode determining means 42 outputs a signal for instructing rectangular data transfer to the plural rectangular transfer means 3. Thereafter, the multiple rectangle transfer means 3 executes data transfer in the flowchart of FIG. 2 as explained in the first embodiment. (606) After receiving the transfer instruction, the transfer mode determining means 42 waits for a transfer end signal from the plural rectangle transfer means 3, and moves to step (611). (607) If it is continuous data transfer,
The transfer mode determining means 42 first uses the transfer trigger generating means 4.
Wait for the trigger signal from 1. At the timing of this trigger signal, the transfer mode determining means 42 outputs a signal for instructing the plural rectangular data transfer means 3 to transfer rectangular data. (608) Upon receiving the transfer instruction, the plural rectangle transfer means 3 executes the data transfer according to the flowchart of FIG. 2 as explained in the first embodiment. (609) The transfer mode determining means 42 waits for a transfer end signal from the plural rectangle transfer means 3 and moves to the next step. (610) After the rectangular data transfer is completed, the transfer mode determining means 42 checks based on the stop flag parameter in the parameter storage means 2 whether or not there is a stop instruction from the window system. This is used to stop continuous transfer when it is necessary to change rectangular parameters, etc. when moving a window. The transfer mode determining means 42 executes step (607) if there is no stop instruction.
) and repeat multiple rectangular data transfer at external trigger timing. If there is a stop instruction, the process moves to step (611). (611) After the transfer is completed, the transfer mode determining means 42 sets the status flag parameter in the parameter storage means 2 to the waiting state (Ready), and executes step (
Return to 602). Here, in this embodiment, the window system is used to control the status flag parameters so that the parameters are not updated during continuous transfer. (memory protection function). In this case, even if the window system erroneously updates parameters during continuous transfer, the parameters are not actually written to memory. Next, a system application example using the data transfer device of this embodiment will be explained. FIG. 7 shows an example in which the data transfer device of this embodiment is used in a workstation or the like to transfer and display moving image data. In FIG. 7, the data transfer device is controlled within the video input device and transfers data from the video buffer memory within the video input device to the frame buffer via a dedicated bus. Transfer using a dedicated bus is not particularly necessary if the system bus has the ability to transfer video data. In the system shown in FIG. 7, the Wind in FIG. 13(b)
When transferring moving image data to owB, the window system follows the flow shown in FIG. The window system first calculates (1) to (3) 3 regarding Window B from the overlap of windows.
Compute two rectangular parameters. Next, in order to set these rectangle parameters, the window system issues a stop instruction to the data transfer device (necessary if continuous transfer is in progress). After giving the stop instruction, it waits until the status flag parameter becomes ready, sets the rectangular parameter in the parameter storage means 2, and instructs the data transfer device to transfer in continuous mode. Thereafter, the data transfer device transfers the moving image data to Windows B without the intervention of the CPU. [0062] If the bus for transferring moving images is high-speed, it is possible to display multiple moving image windows by providing a plurality of moving image input devices. As described above, according to this embodiment, moving image data can be transferred by providing means for continuously transferring data using the same rectangle parameters. In addition, since host CPU intervention is not required during video transfer, host CPU
The PU side has the advantage that real-time control (1/30 second intervals) is not necessarily necessary. In other words, this can be easily realized even under the current general-purpose OS that does not have real-time performance. Further, like still image data, moving image data can also be transferred to one frame buffer and displayed. (Example 3) Next, the third example is shown in FIGS.
This will be explained using FIG. 11. First, when moving image data is transferred by the data transfer device shown in FIG. 5 described above, depending on the timing of the transfer, there is a possibility that display reading and data transfer will collide and the display screen will be disturbed. As shown in FIG. 10, this occurs when data is transferred to Window B while the scanning line of the frame buffer is scanning the line of Window B. To solve this problem, for example, as shown in FIG. 11, a period during which data transfer is prohibited may be detected, and moving image frames may be transferred during a period other than this period. Therefore, in the third embodiment, in addition to the embodiment shown in FIG. 5, the scanning timing of the moving image window is detected from the vertical and horizontal synchronizing signals, and data transfer is started after the scanning of the moving image window portion is completed. It is something to control. A third embodiment of the present invention will be described below with reference to FIG. In FIG. 9, the rectangular data transfer mechanism 1, parameter storage means 2, multiple rectangle transfer control means 3, and continuous data transfer control mechanism 4 are the same as in the embodiment of FIG. 5, and 5 is a transfer period for detecting the timing of video data transfer. It is a detection mechanism. Here, it is assumed that the transfer period detection mechanism 5 detects the moving image data transfer timing from the scanning line and the last line of the moving image window. Reference numerals 51 to 53 constitute the transfer period detection mechanism 5, in which 51 is a transfer rectangular line calculation means, 52 is a read line calculation means, and 53 is a line comparison means. The operation of the data transfer device of this embodiment will be explained below. First, in FIG. 9, the transfer rectangle line calculation means 51 calculates the final line of the transfer window (for example, the maximum y-coordinate value) from the coordinate values of the plurality of rectangles in the parameter storage means 2.
Calculate. This corresponds to Line A in FIG. Further, the readout line calculation means 52 calculates the display readout line from the vertical synchronization signal and horizontal synchronization signal of the screen display. This can be configured, for example, by a counter circuit that is reset by a vertical synchronization signal and counted up by a horizontal synchronization signal. The line comparison means 53 compares the line values of the transfer rectangular line calculation means 51 and the read line calculation means 52 during continuous data transfer, and when the line values match, sends a trigger signal to the transfer trigger generation means 41. This outputs the following. The continuous data transfer control mechanism 4 performs continuous data transfer control according to the flow shown in FIG. 6 based on this trigger. [0075] As a result, video data transfer is performed as shown in FIG.
It can be started after scanning ineA. However, data transfer must be completed by the next transfer prohibited section. As described above, according to this embodiment, by detecting the scanning timing of the moving image window portion and controlling the data transfer to be performed after the scanning of the moving image window portion is completed, it is possible to realize moving image data transfer without display disturbance. . [0077] As explained above, according to the present invention, a data transfer device having the following effects can be provided. In other words, high-speed display of bitmap data is possible under a window system, making it easier for users to run applications that use full-color images, and making it easier to develop and use these applications on general workstations. It can be promoted. Furthermore, by realizing data transfer of multiple rectangles in consideration of the clipping area, compatibility with the window system can be improved, and porting can be performed in a short period of time. Furthermore, support for continuous data transfer makes it possible to transfer moving image data, and since the software uses a 1-frame buffer architecture, there is no need to specialize the handling of moving images (they are treated almost the same as still images). ), the impact on window system porting and application development can be kept to a minimum.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a data transfer device in a first embodiment of the present invention.

[Fig. 2] Operation flowchart of the data transfer device in the first embodiment

FIG. 3 is a block diagram showing the configuration of an application system using the data transfer device of the first embodiment.

[Fig. 4] Processing flowchart of a window system in an application system using the data transfer device of the first embodiment.

FIG. 5 is a block diagram showing the configuration of a data transfer device in a second embodiment of the present invention.

[Fig. 6] Operation flowchart of the data transfer device in the second embodiment.

FIG. 7 is a block diagram showing the configuration of an application system using the data transfer device of the second embodiment.

FIG. 8 is a processing flowchart of a window system in an application system using the data transfer device of the second embodiment.

FIG. 9 is a block diagram showing the configuration of a data transfer device in a third embodiment of the present invention.

[Figure 10] An explanatory diagram of the scan timing of the display screen when displaying a video window

[Figure 11] Timing control diagram during video data transfer

[Fig. 12] An explanatory diagram showing the configuration of a conventional video display system.

[Figure 13] Explanatory diagram of a multi-window screen example of the window system

[Figure 14] Processing flowchart of a window system when using a conventional data transfer device

[Explanation of symbols]

1 Rectangular data transfer mechanism 2 Parameter storage means 3 Multiple rectangle transfer control means 4 Continuous data transfer control mechanism 5 Transfer period detection mechanism 11 Address generation means 12 Data control means 13 Rectangular transfer control means 41 Transfer trigger generation means 42 Transfer mode determination means 51 Transfer rectangle line calculation means 52 Readout line calculation means 53 Line comparison means

Claims (3)

[Claims] 1. Address generation means for generating a memory address corresponding to the coordinate value from a two-dimensional rectangular coordinate value;
data control means for controlling input/output of data to and from the memory; rectangular transfer control means for controlling the transfer flow of the rectangular data for each of the means; parameter storage means for storing transfer parameters for a plurality of rectangles; A data transfer device comprising a transfer control means or a plurality of rectangular transfer control means for controlling the address generation means to transfer a plurality of rectangular data stored in the parameter storage means. 2. Transfer trigger generation means for storing a transfer mode parameter for selecting whether or not to continuously transfer multiple rectangular data in the parameter storage means, and generating a data transfer start trigger in synchronization with an external signal. 2. The data transfer apparatus according to claim 1, further comprising: transfer mode determining means for causing data transfer to be performed continuously at timing from said transfer trigger generating means when said transfer mode parameter is continuous transfer mode. 3. Parameter storage means for storing a rectangular transfer parameter; address generation means for generating a memory address corresponding to the coordinate value from the two-dimensional rectangular coordinate value of the rectangular parameter; and input/output of data to and from the memory. and rectangular transfer control means for controlling the transfer flow of the rectangular data for each of the means,
In data transfer to a frame buffer, the transfer rectangular period detection means detects a scanning period of a transfer rectangular area within a display scanning period of the frame buffer and generates a trigger signal at the end of the detected period. A data transfer device that transfers data at the timing of