How to make a scrolling texr for LCD controller?

Discussion in 'Programmer's Corner' started by Jeff, Dec 12, 2004.

  1. Jeff

    Thread Starter New Member

    Dec 12, 2004
    hi guys i am currently doing a project for my school. can anyone guide me on how to do a scrolling text display on LCD controller using VHDL? The LCD i am using is a 14 pin. Please provide me with guidance or the source code as soon as possible because my due date is near. Thanks a lot
  2. cyberhehe

    Well-Known Member

    Oct 6, 2004

    Are you limited to use VHDL for that, or can you use MCU's with built in LCD drivers for you purpose?
  3. Jeff

    Thread Starter New Member

    Dec 12, 2004
    yes i can only use VHDL for my project,i am not sure about MCU, but i am implementing it onto the Xilinx board.
    by the way i found this outline on the net for scrolling text,but i am new to VHDL.
    heres the outline:

    First, create a memory array that holds the character values and treat
    it like a circular buffer from which the character values can be read.
    Use the array construct to create an array of 16 8-bit
    std logic vectors. Then use concurrent signal assignments to as-
    sign the appropriate ASCII value to each element of the array to spell
    out your name. Any blank characters should be filled in with the space
    character, 0x20.
    Create a process that implements a 0-15 counter called offset. This
    process should be clocked on the falling edge of a 1 Hz clock signal,
    and offset should be defined as an std logic vector(3 downto
    Finally, change the line that assigns lcd data to use the character
    array created earlier indexed by (addr in + offset). By truncating the
    flow bit in this summation, we can achieve the modulus operation.
    This trick, of course, only works for mod'ing by powers of 2.
    Remember to get checked-offset by the teaching assistant before continuing!
    Report for Laboratory 3