Abstract:
A method for processing display data includes: storing an image data in a plurality of first-type memories by taking scanning line data as a unit; providing one of the scanning line data stored in a particular memory of the first-type memories to one of a plurality of second-type memories, the particular memory being one of the first-type memories, which are not receiving and storing the image data; and outputting the scanning line data stored in the second-type memories. Time periods for outputting the scanning line data of the image data from the second-type memories are not overlapped.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is based upon and claims the benefit of priority from the prior Taiwanese Patent Application No. 097113373, filed Apr. 11, 2008, the entire contents of which are incorporated herein by reference. 
       BACKGROUND 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a method for processing display data, and more particularly, to a method for processing display data, which employs scanning lines as processing units. 
         [0004]    2. Description of the Related Art 
         [0005]    With wide use of various displays in daily life, users are not satisfied to transmit information only by images. There is a further need to improve the quality of the images. To improve the quality of the images, it should increase scanning frequencies of the displays. However, with increasing the scanning frequencies of the displays, data needed to be processed in a predetermined time period are increased doubly. Thus it will largely increase the amount of data memories for the images. 
         [0006]    Generally, there should be more input ports than output ports when processing images (for example the amount of input ports is double that of the output ports, that is including four input ports and two output ports), such that a time period for receiving data is double that for sending out the data. Because of the time relation between inputting/outputting, a conventional technology employs three groups of double data rate random access memories (DDRRAM) as a storing space for display data. 
         [0007]    Referring to  FIG. 1 , a sequence diagram of a conventional method for processing image data is provided. As shown in  FIG. 1 , the image data are continuously inputted into DDRRAM of an image buffer. Time periods are in relation to the DDRRAM and the sequence for the data in here. For example, DDR 1 _W 1  are first image data written into a first group of DDRRAM; DDR 2 _W 1  are first image data written into a second group of DDRRAM; and DDR 3 _W 1  are first image data written into a third group of DDRRAM. Furthermore, DDR 1 _W 2  are second image data written into the first group of DDRRAM; DDR 2 _W 2  are second image data written into the second group of DDRRAM; and DDR 3 _W 2  are second image data written into the third group of DDRRAM. 
         [0008]    As shown in  FIG. 1 , in the time period DDR 1 _W 1 , a group of image data are written into the first group of DDRRAM. After the time period DDR 1 _W 1 , that is, after the first group of DDRRAM receives the group of image data, the first group of DDRRAM begins to output the image data stored therein to another buffer (called as display buffer in following) for being displayed in a display. The output performance operates in the time period DDR 1 _R 1  as shown in  FIG. 1 . Similarly, in the time period DDR 2 _W 1 , another group of image data are written into the second group of DDRRAM. After the time period DDR 2 _W 1 , the second group of DDRRAM outputs the image data stored therein to the display buffer in the time period DDR 2 _R 1  as shown in  FIG. 1 . In addition, in the time period DDR 3 _W 1 , other group of image data are written into the third group of DDRRAM. After the time period DDR 3 _W 1 , the third group of DDRRAM outputs the image data stored therein to the display buffer in the time period DDR 3 _R 1 . 
         [0009]    From  FIG. 1 , it is obvious that three groups of DDRRAMs must be employed to successfully input and output the data in the condition that the amount of the input ports is double that of the output ports. Thus the manufacturers seek methods for decreasing the manufacturing cost in the modern society with the keen competition and the gradual increasing material cost. However, the manufacturers are limited by the above design, and cannot find an excellent reformative method. 
         [0010]    What is needed, is providing a method for processing image data, which can solve the above problems. 
       SUMMARY OF THE INVENTION 
       [0011]    A method for processing display data in accordance with an exemplary embodiment of the present invention is provided. The method is adapted into a display to scan a plurality of scanning lines just one time for displaying an image data. The image data comprises a plurality of scanning line data, and each scanning line data is configured for displaying on one corresponding scanning line. The method comprising: storing the image data in a plurality of first-type memories by taking one scanning line data as a unit; providing one of the scanning line data stored in a particular memory of the first-type memories to one of a plurality of second-type memories, the particular memory being one of the first-type memories, which are not receiving and storing the image data; and outputting the scanning line data stored in the second-type memories. Time periods for outputting the scanning line data of the image data from the second-type memories are not overlapped. 
         [0012]    A method for processing display data in accordance with another exemplary embodiment of the present invention is provided. The method is adapted to a display having an image buffer and a scanning line data buffer. The image buffer includes a plurality of first-type memories, and the scanning line data buffer includes a plurality of second-type memories. The method comprises: storing a first scanning line data in a first particular memory of the first-type memories; storing a second scanning line data in a second particular memory of the first-type memories; providing the first scanning line data from the first particular memory of the first-type memories to a first particular memory of the second-type memories; providing the second scanning line data from the second particular memory of the first-type memories to a second particular memory of the second-type memories; and, when the first scanning line data and the second scanning line data are included in a same frame, outputting the first scanning line data stored in the first particular memory of the second-type memories and the second scanning line data stored in the second particular memory of the second-type memories such that the output first scanning line data and second scanning line data are not overlap. 
         [0013]    A method for processing display data in accordance with other exemplary embodiment of the present invention is provided. The method is adapted to a display having an image buffer and a scanning line data buffer. The method comprises: storing a first scanning line data and a second scanning line data in the image buffer; reading out the first scanning line data from the image buffer in a first time period, and starting to write the first scanning line data into the scanning line data buffer in the first time period; outputting the first scanning line data form the scanning line data buffer in a second time period; and reading out the second scanning line data from the image buffer in a third time period, starting to write the second scanning line data into the scanning line data buffer and starting to output the written second scanning line data from the scanning line data buffer synchronously when the second scanning line data being written into the scanning line data buffer. 
         [0014]    A method for processing display data in accordance with other exemplary embodiment of the present invention is provided. The method is adapted to a display having an image buffer and a scanning line data buffer. The image buffer includes a plurality of first-type memories. The method comprises: storing a first scanning line data in a first particular memory of the first-type memories; storing a second scanning line data in a second particular memory of the first-type memories; storing the first scanning line data of the first particular memory in the scanning line data buffer, and starting to output the first scanning line data from the scanning line data buffer after reading out completely the first scanning line data from the first particular memory; and storing the second scanning line data of the second particular memory in the scanning line data buffer, and outputting the second scanning line data from the scanning line data buffer synchronously when the second scanning line data start to be stored in the scanning line data buffer. 
         [0015]    The present invention employs only two groups of memories in the image buffer to display normally images. Compared with the conventional arts which employ at least three groups of memories as the image buffer, the present invention can obviously decrease the amount of memory usage. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which like numbers refer to like parts throughout, and in which: 
           [0017]      FIG. 1  is a sequence diagram of a conventional method for processing display data; 
           [0018]      FIG. 2A  and  FIG. 2B  are sequence diagrams of a method for processing display data, in accordance with an exemplary embodiment of the present invention; 
           [0019]      FIG. 3  is a detailed sequence diagram of the method for processing display data, in accordance with the exemplary embodiment of the present invention; 
           [0020]      FIG. 4A  to  FIG. 4C  are sequence diagrams of a method for processing display data, in accordance with another exemplary embodiment of the present invention; and 
           [0021]      FIG. 5  is a sequence relation diagram between an original blanking period of a display system and a time for DDRRAM processing a scanning line data. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0022]    Reference will now be made to the drawings to describe exemplary embodiments of the present driving circuit, in detail. The following description is given by way of example, and not limitation. 
         [0023]    Referring to  FIG. 2A and 2B , a sequence diagram of a method for processing image data in accordance with an exemplary embodiment of the present invention, is provided. It should be noted, the exemplary embodiment employs scanning lines as processing units to process image data. Briefly speaking, current displays display the image data thereon in a sequence from left to right and from up to down, to form a whole image. Each line from left to right is called as a scanning line in this processing method. Therefore, the display data are composed of a plurality of frames of image data, and each frame of image data may be divided into a plurality of scanning line data. Each scanning line data is configured as data when a scanning line of an image is displayed. Furthermore, since the speed of inputting the image data is generally quicker than that of outputting the image data to be displayed, this exemplary embodiment employs two groups of double data rate random access memories (DDRRAM) as image buffers for receiving the image data, and four groups of static random access memories (SRAM) as scanning line data buffers when outputting the image data. In the present invention, DDRRAM may have a same operation frequency to that of SRAM. Alternatively, the operation frequency of DDRRAM can be larger than that of SRAM, but the amount of the input ports of SRAM is increased correspondingly to make the time period for reading the image data from DDRRAM be the same as that for writing the same image data into SRAM. 
         [0024]    The following will explain the means of signs as shown in  FIG. 2A ,  2 B, and  4 A to  4 C. DDR 1 _W represents data written into the first group of DDRRAM, and following panes represent corresponding operations in corresponding time periods, such as written scanning line data. Signs indicated in the panes represent operated objects. For example, L 1 (N- 1 ) represents the first scanning line data of the N- 1  frame of the image data; L 3 (N) represents the third scanning line data of the N frame of the image data. Similar signs are adapted in DDR 2 _W (data written into a second group of DDRRAM), DDR 1 _R (data read from the first group of DDRRAM), DDR 2 _R (data read from the second group of DDRRAM) and SRAM 1 ˜ 4  (data read from the 1˜4 groups of SRAM). 
         [0025]    In this exemplary embodiment, each frame of image data includes eight scanning line data to describe the related technology of the present invention. This exemplary embodiment employs two groups of DDRRAM to receive each frame of image data. The scanning line data L 1 (N- 1 ), L 3 (N- 1 ), L 5 (N- 1 ), L 7 (N- 1 ), L 2 (N), L 4 (N), L 6 (N) and L 8 (N) are written into the first group of DDRRAM, and the scanning line data L 2 (N- 1 ), L 4 (N- 1 ), L 6 (N- 1 ), L 8 (N- 1 ), L 1 (N), L 3 (N), L 5 (N) and L 7 (N) are written into the second group of DDRRAM. 
         [0026]    Time periods t 1 ˜t 18  as shown in figures, have same time lengths. From figures, in the time period t 1 , the scanning line data L 1 (N- 1 ) are written into the first group of DDRRAM. Next, in the following time period t 2 , the scanning line data L 2 (N- 1 ) are written into the second group of DDRRAM. Orderly, the eight scanning line data of the N- 1  frame of image data are stored into the two groups of DDRRAM respectively. 
         [0027]      FIG. 3  is a sequence diagram of the method for processing display data in accordance with an exemplary embodiment of the present invention. After the scanning line data L 1 (N- 1 ) are written into the first group of DDRRAM (DDR 1 _W 1  as shown in  FIG. 3 ), the scanning line data L 1 (N- 1 ) are read out in the time period t 2  (DDR 1 _R 1  as shown in  FIG. 3 ) and stored into the first group of SRAM (S 1 _W 1  as shown in  FIG. 3 ) of the scanning line data buffer. The first group of SRAM receives the scanning line data L 1 (N- 1 ) in the time period t 2 , and outputs the scanning line data L 1 (N- 1 ) to be displayed (S 1 _R 1  as shown in  FIG. 3 ) in the time periods t 3  and t 4  (assuming the speed for inputting the image data is double that for outputting the image data). The scanning line data L 1 (N- 1 ), L 3 (N- 1 ), L 5 (N- 1 ) and L 7 (N- 1 ) for the odd scanning lines of the N- 1  frame of the image data are processed by the above mode, and are outputted to be displayed after the scanning line data are completely written into the SRAM. The difference in processing the odd scanning lines in the N- 1  frame is using different SRAM, thus the processing mode for the other odd scanning lines is not described. 
         [0028]    Referring to  FIGS. 2A ,  2 B and  3 , from another aspect, the scanning line data L 2 (N- 1 ) are written into the second group of DDRRAM (DDR 2 _W 1  as shown in  FIG. 3 ) in the time period t 2 . Next, the scanning line data L 2 (N- 1 ) are read out (DDR 2 _R 1  as shown in  FIG. 3 ) from the second group of DDRRAM in the time period t 5 . The scanning line data L 2 (N- 1 ) read from the second group of DDRRAM are written into another group (defined as the second group) of SRAM (S 2 _W 1  as shown in  FIG. 3 ) in the time period t 5 . Different from the mode of processing the odd scanning lines data, the scanning line data L 2 (N- 1 ) are read out from the second group of SRAM to be displayed (S 2 _R 1  as shown in  FIG. 3 ) when being written into the second group of SRAM. However, because of the limitation of the speed for outputting, the operating time for outputting the scanning line data L 2 (N- 1 ) from the second group of SRAM includes the two time periods t 5  and t 6 . Similarly, the scanning line data L 2 (N- 1 ), L 4 (N- 1 ), L 6 (N- 1 ) and L 8 (N- 1 ) for the even scanning lines of the N- 1  frame of the image data are processed substantially by the above mode, and are outputted to be displayed when the scanning line data are written into the SRAM. The difference in processing the even scanning lines in the N- 1  frame is using different SRAM, thus the processing mode for the other even scanning lines is not described. 
         [0029]    The key of the method of this exemplary embodiment is that because the DDRRAM cannot be written and read synchronously, the scanning line data should be read when the DDRRAM is in the non-writing condition. Furthermore, each scanning line data of a same frame of image data must be linked and not overlapped with the above scanning line data thereof when being outputted for being displayed, such that the images are linked smoothly. Therefore, after one odd scanning line data are outputted to the SRAM from the DDRRAM, the next scanning line data of the same frame of the image data are outputted to the SRAM from the DDRRAM after two time periods. Oppositely, after one even scanning line data are outputted to the SRAM from the DDRRAM, the next scanning line data of the same frame of the image data are outputted to the SRAM from the DDRRAM in the next time period. For example, the scanning line data L 1 (N- 1 ) are displayed in the time periods t 3  and t 4 ; the scanning line data L 2 (N- 1 ) are displayed in the time periods t 5  and t 6 ; the scanning line data L 3 (N- 1 ) are displayed in the time periods t 7  and t 8 ; the scanning line data L 4 (N- 1 ) are displayed in the time periods t 9  and t 10 , and so on. The N- 1  frame of image data finish to be displayed after the scanning line data L 8 (N- 1 ) are displayed in the time period t 17  and t 18 . 
         [0030]    Please return to  FIGS. 2A and 2B , the method for processing the scanning line data L 1 (N), L 2 (N) . . . L 8 (N) of the N frame of image data is similar to the method for processing the scanning line data L 1 (N- 1 ), L 2 (N- 1 ) . . . L 8 (N- 1 ) of the N- 1  frame of image data, except that the odd scanning line data of the N frame of image data are stored into the second group of DDRRAM, and the even scanning line data thereof are stored into the first group of DDRRAM. Similarly, the scanning line data (the even scanning line data, such as the scanning line data L 2 (N) and L 4 (N)) stored into the first group of DDRRAM are displayed after being completely written into the SRAM. The scanning line data (the odd scanning line data, such as the scanning line data L 1 (N) and L 3 (N)) stored into the second group of DDRRAM are displayed at the same time of being written into the SRAM. 
         [0031]    Referring to  FIGS. 4A to 4C , sequence diagrams of a method for processing display data in accordance with another exemplary embodiment of the present invention are provided. The method for processing each frame of image data in this exemplary embodiment is similar to that as shown in  FIGS. 2A and 2B , except that a blanking period of this exemplary embodiment has a different time length. However, from the  FIGS. 4A to 4C , it is known that the method of this exemplary embodiment can be adapted to display systems have blanking periods with different time lengths. It should be noted that, although the present invention writes the scanning line data into the first group of DDRRAM as a start, the start may be writing the scanning line data into the second group of DDRRAM. Various changes can be made obviously from the above embodiments and the description, thus they are not described in following. 
         [0032]    From the embodiments as shown in  FIGS. 2A to 2B  and  4 A to  4 C, it is known that the method for processing display data provided by the present invention can be operated no matter which group of DDRRAM do the scanning line data start to be written into, if the time lengths of the blanking periods, such as the time period t 9  and t  18  as shown in  FIGS. 2A and 2B  or the time periods t 8 ˜t 12  as shown in  FIGS. 4A to 4C , are integer times as the time period for the DDRRAM reading/writing one scanning line data. 
         [0033]    However, there are not all display systems having blanking periods which have the time lengths integer times as the time for the DDRRAM reading/writing one scanning line data. Thus the time lengths of the blanking periods should be adjusted in some conditions. The present invention adjusts the blanking periods according to the time for processing the scanning line data directly. Referring to  FIG. 5 , a sequence relation diagram between an original blanking period of the display system and the time for DDRRAM processing one scanning line data is provided. From  FIG. 5 , the original blanking period (from a time point tf to a time point tr) is substantially equal to one and a half time period for processing the scanning line data (DDR_SP). To adjust the original blanking period to have a suitable length, after starting the original blanking period (the time point tf), the image data of the next frame start to be processed after take count of a suitable amount of DDR_SP forcedly. Therefore, the time point tf is delayed suitably to fit the present invention. Alternatively, the data stored in the SRAM are properly output to adjust the blanking period between the two frames, such that the blanking period between the two frames are adjusted to be integer times as the time for displaying each scanning line data. For example, image data that are to be shown on an area that cannot be seen by the users are partially or repeatedly output from the SRAM such that blanking period between the two frames can be adjusted. 
         [0034]    From the above, the method for processing display data of the present invention employs only two groups of DDRRAM in the image buffer to display normally images. Compared with the conventional arts which employ at least three groups of DDRRAM as the image buffer, the present invention can increase the memory elements. 
         [0035]    The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the invention disclosed herein, including configurations ways of the recessed portions and materials and/or designs of the attaching structures. Further, the various features of the embodiments disclosed herein can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the scope of the claims is not to be limited by the illustrated embodiments.