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1、1-4244-0216-6/06/$20.00 2006 IEEE Design and Implementation of a Table-based GUI for MP3 Players Ying-Wen Bai and Fu-En Tsai Abstract In addition to the two present methods for system control programming mechanism of MP3 players, due to the marketing competition of MP3 players, there is a need for a
2、 fast GUI design for various customers. The first method stores only the boot code in the ROM of the controller. The main program is stored in the NAND flash which includes the initializing program code. As long as the initialization is completed, the program code will be loaded into the system from
3、 the NAND flash. The advantages of this method are that the main program can update the GUI anytime and provide more flexibility. However, the chip area will increase due to the need of RAM for storing the program. The second method is to store the main program into the ROM of the controller, by whi
4、ch this design does not need to use an extra RAM in order to save the chip area. However, when the main program is once stored into the ROM, the function of the MP3 player can not change any more. In this paper, we propose a table based GUI design which provides a fast way to obtain the different pr
5、ogrammable GUI from the prestored NAND flash. A couple of tables are used to support various customer GUIs, such as, a command table for the basic operational procedure, a display table for the basic display components, a manual table for the basic function of the MP3 player and a key table for the
6、key function used with the MP3 operation. These tables can be prestored in the NAND flash module. When users turn on the MP3 player, the main program of the MP3 player will load in the customer required tables. Hence, by using our design, a different set of these tables will provide users with diffe
7、rent GUIs even if the same chip set in the hardware modules is utilized1. Index Terms Table-based GUI, MP3 Player. I. INTRODUCTION According to marketing reports, the portable compressed audio (MP3) player market continues to surge, led by the portable flash player category which is expected to incr
8、ease from 26.4 million units shipped worldwide in 2004 to nearly 124 million units in 2009 1. Hence, a lot of companies are actively involved in the MP3 industry, but now the difference in making products is becoming more and more important. The products differ in their “ functions” , “ appearance”
9、and “ user interface” How can a MP3 player 1 Ying-Wen Bai is with the Department of Electronic Engineering, Fu Jen Catholic University, Taipei, Taiwan, 242, R.O.C.(e-mail : baiee.fju.edu.tw) Fu-En Tsai is a graduate student of Fu Jen Catholic University, Taipei, Taiwan, 242, R.O.C. (e-mail : ) appea
10、r to have a different user interface? How can an engineer quickly and efficiently reach the different user interfaces? Usually, a MP3 player design of reaching different user interfaces can be classified into three methods as shown in Fig. 1. The first method uses an inside ROM preserves boot code i
11、n controlling the chip, and leaves the main program in NAND Flash. The program controls and only preserves and initializes necessary the procedure yard systematically within the chip. The procedure is divided into when it will reach the NAND Flash. After initializing and finishing, the block is writ
12、ten into the system. The major advantage of this method it is update the user interface at any time for the main program. Also, the function elasticity is very great. But the shortcoming is the program needs to use RAM to preserve the procedure within the chip, resulting in an increased chip area 2.
13、 The second method is to plant the whole procedure into a controller in the main chip, which does not need to use RAM to preserve the procedure externally, thus saving the chip area as the ratio between the RAM and ROM is 8. However, the shortcoming is planting the control code into the ROM chip, wh
14、ich is unable to upgrade again. That is to say that this method can only support a certain specific function, namely pictures or a button. Functions shown are all unable to be modified again after chip fabrication 3. Method 1 MP3 controller Boot ROM NAND Flash Main program + Font Method 2 MP3 contro
15、ller Main program NAND Flash Font Method 3 MP3 controller Main program NAND Flash Specialize table + Font Fig. 1. The three design methods of MP3 players for realizing the GUI. This paper proposes a third method, which has the advantages of a combination of the two present methods. This method regar
16、ds the procedure structure of the ROM base as the prerequisite, and utilizes the NAND Flash to pass the USB renewable characteristic at any time, so the designer can leave the information content as a picture shown in NAND Flash, which can make specific display information by using NAND Flash after
17、the system starts the machine, which then reconfigures into a new operation interface. Thus, even by planting the control procedure into a controller chip, one can still load the differently designed GUI tables from the NAND Flash. Hence, the designer can provide a different display interface, the d
18、ifferent button assignments and functions, and also offer the multiple GUIs of a MP3 player even using the same chip set 4, 5. Section 2 introduces the data structure and the operating detail of the command table, the display table, the key table and the menu table. In addition, these five tables pr
19、ovide the basic guidelines of the system operation including the kind of key functions and how to change the display. Section 3 shows the implementation results which include the different GUIs, the table sizes and the accessing speed for our design. Section 4 draws a conclusion. II. DESIGN AND IMPL
20、EMENTATION In order to provide a user interface with different ways and characteristics, the button assignments and the button functions, we create a mechanism based on the Table interpretation to create various kinds of user interfaces and to set the function definitions of the buttons. Table I sho
21、ws the basic functions of the command table, the display table, the key table, the menu table and the system table 6. TABLE I THE BASIC FUNCTIONS OF THE COMMAND TABLE, THE DISPLAY TABLE, THE KEY TABLE, THE MENU TABLE AND THE SYSTEM TABLE Table Types Functions Command table Show command selections. D
22、isplay table Support the different size of the screen. Offer different information to show the position of the figure. Offer different holding/shut-down picture. Menu table Offer different functions to select the single order to adjust. Key table Offer different quantity of buttons. Offer different
23、button function associations. System table Support different LCMs and driver ICs. Offer multi-language selections. Establish systematic initial value. Through the combination of both a display table and a command table, Fig. 2 shows the control procedure for showing a GUI on the screen. Decode the r
24、ecord Display Next record of display table Stop Y N Get command offset Get 1st record of display table Get next record of display table Fig. 2. The flow chart for showing a GUI picture The main program will access the display command first, and then find the first record of the display table from th
25、e command table. The record content, 8 Byte, taken out from the display table is decoded, and show on the screen. Every entry of the display table will tell whether the procedure will connect to the next display table. If the connection of the display table exists, the connection will be repeated ba
26、sed on the previous procedure. Other the other words, if the connection of the display table does not exist, the display information of the screen will be terminated. A. Command Table Table II shows the order of collection to start the picture displays; each one of the commands likes a painting brus
27、h to draw a block of the pictures. Each command defines the position expressed with 2 Byte of its affiliated first display table well in advance, after starting in order, the procedure will read the content of the first field of the display table (8 Bytes), decoded by this content, the control progr
28、am can know which kind of picture information will be shown and will be connected to the next display table. The control program can draw the whole picture in a connection order of blocks. A certain mapping relationship will be verified between the block information and the possible picture displayi
29、ng 6. TABLE II THE COMMAND GROUPS MP3 command group GUI command group MP3_PLAY_FILE_NAME MENU_MAIN_MENU MP3_PLAY_LYRICS MENU_MP3_ SETTING MP3_PAUSE_FILE_NAME MENU_VOC_ SETTING MP3_PAUSE_LYRICS MENU_FM_ SETTING MP3_PAUSE MENU_EQ MP3_STOP MENU_CONTRAST MP3_FORWARD MENU_REPEAT MP3_BACKWARD MENU_BACKLIG
30、HT MP3_NEXT MENU_LANGUAGE MP3_PREVIOUS MENU_SLEEP MP3_UPDATE_TIME MENU_SD_FLASH MP3_REVERSE_TIME MENU_DELET MP3_HORSE A typical MP3 player provides the selection of the songs shown on the screen including, the song quantity, the playing time, the song name, the lyrics, the singer, the sample frequen
31、cy, and the sound of environment. In addition, the battery capacity and the circulation way will be set, so we need express the operation contents of each selection in the display table. The display tables show how to build and construct a set of methods to display the picture effectively. Some info
32、rmation in the display table used by the control program control the action in order to show all the blocks in the whole screen. Example: MP3_PLAY_FILE_NAME: This operation order of the MP3 player shows a set of blocks by the program name With this connection order, the control program will show the
33、 information from left to right. In this example, the system shows the state of the battery, the SD cards, the circulation way, the A-B circulation, the locking with button, the function way, the file name, the compression ratio, and the sample frequency. Fig. 3 shows 13 pieces of information which
34、are consists of 13 entries in the display tables. Fig. 3. MP3_PLAY_FILE_NAME picture shown according to the command table. B. Display table The display table as shown in Table III includes many elementary cells that represent the each basic part of the GUI picture. The elementary cells describe main
35、ly the position of the GUI picture on the screen, which the contents are stored in NAND Flash and the connection for the next entry of the display table. We have designed the display table to meet the demand of the GUI pictures; the control program only needs to follow the predefined rules to confir
36、m the meaning of the content of each field in the table 7. TABLE III A RECORD FORMAT OF THE DISPLAY TABLE 1 Byte 1 bit 2 Byte 1 Byte 1 Byte 3 bit 1 bit 1 bit 0= bitmap Start address Display area code name 1= text Code name Length Cell size File name Shift pixel Contrast reverse 0= non-reverse 1= rev
37、erse stop 0= next 1= end Table IV shows the record format of the display table stored in NAND flash and it takes space of 8 Bytes. TABLE IV THE FORMAT OF THE DISPLAY TABLE Display area code name Byte 0 1 Bitmap address offset/Text item low order byte Byte 1 0 Bitmap address offset/Text item high ord
38、er byte Byte 2 0 Display length Byte 3 5 Cell size Byte 4 0 B/T Shift Pixel Reverse Stop Reserve Reserve Byte 5 0 0 0 0 0 0 x x Byte 6 Reserve Byte 7 Reserve 1) Cell size We regard the whole picture as a piece of drawing paper, which we cut it into different sizes of the same cells according to the
39、demand, and entrust a serial number to each demand. As an example, the display screen of 128x64. If the GUI picture was not finished with the cutting apart of cells, the screen which will show 128*64 =8192 dots, which will be comparatively complicated when the position of each primitive component is
40、 arranged. When the whole picture is cut into a small block or, a cell with dot matrix size of 8x8, the whole picture will be turned into 128 blocks, and will be comparatively simple to manage. The information for the position of each block can consist of several cells on the screen 8. We use the le
41、ngth of 1 Byte to define the size of different cells, so our design can define 64 kinds of different cell sizes at most as shown in Table V. TABLE V AN EXAMPLE OF THE CONTENT OF THE CELL SIZE Code name Cell size Representation 0 8x8 Cell size 1 16x16 Cell size 2 16x12 For lyrics 3 16x8 For half a sh
42、ape word 4 16x16 For the whole shape word We can insert the code name in the cell size field of the display table. This control program can be used to judge the cell size and used to divide the whole picture into small blocks. 2) Display area code name The display area determines the information sho
43、wn in the block or cell position on the screen. After dividing the whole screen into cells with the same size, one can begin to define the block information showing that the block can be made up of several cells, Fig. 4 and Fig. 5 show mapping relationship between the display position and the batter
44、y symbol. Fig. 4. The battery display position C 0 C 1 C 2 C 3 C 4 C 5 C 6 C 7 C 8 C 9 C 10 C 11 C 12 C 13 C 14 C 15 P011110 0 0 0 0 0 0 0 0 0 0 0 P111110 0 0 0 0 0 0 0 0 0 0 0 P20 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 P30 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 P40 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 P50 0 0 0 0 0 0 0 0 0
45、 0 0 0 0 0 0 P60 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 P70 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Fig. 5. The battery display position In our design, if the battery block has 8 cells in the upper left corner, then we fill out the value of these 8 cells as 1 as shown in Fig. 4, and the others are all filled out as 0.
46、 Table VI lists all positions of the blocks that need to be shown one by one via such a predefined layout. We use the length of 1 Byte to define different display area code names, At most, we can define 64 kinds of different display area code names. Our design provides one display area with 32 Byte
47、in NAND Flash, but the current design only uses 16 Byte. The unused part is filled by 0. Later, we can define all kinds of display areas according to the whole picture shown on the screen. Track number Bit rate Sampling rate EQ mode Battery statusSD card Repeat mode A-B repeat Lock Function mode Pla
48、y Icon Play time File name TABLE VI DISPLAY AREA CODE NAME No. Expressing value comment 0 0 xf0,0 x00,0 xf0,0 x00,0 x00,0 x00,0 x00,0 x00, 0 x00,0 x00,0 x00,0 x00,0 x00,0 x00,0 x00,0 x00 battery We can insert the code name in the display area code name field of the display table, and the program can
49、 interpret this field and then show the information in the correct position on the screen. 3) Bitmap/text Fig. 3 shows the information with 1 bit to determine the regular appearance or the modification. Bitmap (regular): This field will vary after it is established by the users, such as, “ SD card” , “ Repeat mode” , “ A-B repeat” , “ Lock” , “ Function mode” , “ Play Icon” and “ EQ mode” , the field can be controlled from the buttons by the users. Text (modification): The program interprets this information. For example, t