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    Please can you explain me this font 8X8 row and col adress

    hi

    can somebody explain me, how does work this
    [5:0] char_row = row_addr[8:3];
    [2:0] font_row = row_addr[2:0]; //char row 8x8
    [6:0] char_col = col_addr[9:3];
    [2:0] font_col = col_addr[2:0]; // char col 8x8

    this 8X8 font but the address [8:3] for row and adress for col [9:3], what does do this bit 4 in row and column
    thnx

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    Re: please can you explain me this font 8X8 row and col adress

    Quote Originally Posted by michael 1978 View Post
    hi

    can somebody explain me, how does work this
    [5:0] char_row = row_addr[8:3];
    [2:0] font_row = row_addr[2:0]; //char row 8x8
    [6:0] char_col = col_addr[9:3];
    [2:0] font_col = col_addr[2:0]; // char col 8x8

    this 8X8 font but the address [8:3] for row and adress for col [9:3], what does do this bit 4 in row and column
    thnx
    You are not mention the surrounding circuit so it's a bit hard do know what you want to obtain, but try to have a look here this is a good explanation of how a font are used for VGA

    https://www.fpga4fun.com/GraphicLCDpanel4.html


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    Re: please can you explain me this font 8X8 row and col adress

    Quote Originally Posted by Wiljan View Post
    You are not mention the surrounding circuit so it's a bit hard do know what you want to obtain, but try to have a look here this is a good explanation of how a font are used for VGA

    https://www.fpga4fun.com/GraphicLCDpanel4.html
    hello
    i just dont understand the
    wire [3:0] LCDdata = CounterX[0] ? raster8[7:4] : raster8[3:0]; raster8[7:4] the bit 4(5) is the ram character?



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    Re: please can you explain me this font 8X8 row and col adress

    Quote Originally Posted by michael 1978 View Post
    hello
    i just dont understand the
    wire [3:0] LCDdata = CounterX[0] ? raster8[7:4] : raster8[3:0]; raster8[7:4] the bit 4(5) is the ram character?
    This is a mux with the lower bit of CounterX being the select which is what the text above it describes
    ecause my LCD panel takes 4-pixels per clock, we need 2 clocks for 1 character width (1 character width=8 pixels). That's why "Character RAM" uses "CounterX[6:1]" instead of "CounterX[5:0]" above.
    So for 8-pixels you need 2 clocks. I'm assuming the raster8 contains the pixels and the LCD takes 4-bit data, so hence the mux. Selecting between the raster[7:4] and then raster8[3:0].



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    Re: Please can you explain me this font 8X8 row and col adress

    You will need to tell the FONT look-up ROM what character to show eg A,B,C....(ASCII) and what Row (Line) and Column(Pixel)
    To make it a bit more easy to use you will typical write your text to a RAM with the message to show like (Hello World)
    So you will also need to tell the RAM what output position you message you want to send to your FONT ROM

    There are many FPGA VGA examples on the web like here:
    https://opencores.org/projects?expan...o%20controller



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    Re: please can you explain me this font 8X8 row and col adress

    Quote Originally Posted by ads-ee View Post
    This is a mux with the lower bit of CounterX being the select which is what the text above it describes

    So for 8-pixels you need 2 clocks. I'm assuming the raster8 contains the pixels and the LCD takes 4-bit data, so hence the mux. Selecting between the raster[7:4] and then raster8[3:0].
    thank you man for time....i think i understand

    - - - Updated - - -

    Quote Originally Posted by Wiljan View Post
    You will need to tell the FONT look-up ROM what character to show eg A,B,C....(ASCII) and what Row (Line) and Column(Pixel)
    To make it a bit more easy to use you will typical write your text to a RAM with the message to show like (Hello World)
    So you will also need to tell the RAM what output position you message you want to send to your FONT ROM

    There are many FPGA VGA examples on the web like here:
    https://opencores.org/projects?expan...o%20controller
    thanks....

    - - - Updated - - -

    thnx to everyone for help
    greetings..



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