HD44780 LCD Display Interfacing with Altera FPGA & VHDL

HD44780_LCD_DISPLAY_01My latest project involves programming an Altera Cyclone II FPGA for direct control over the popular HD44780 LCD Display controller.
I am using the ALTERA DE2 development board for testing and debugging my VHDL code as this board also uses the HD44780 LCDDisplay unit.
Altera_DE2Using VHDL, we’ll be able to encode various Finite State Machines which are used to produce the specific signal timing requirements to initialize the LCD.

LCD_DISPLAY_Controller_VHDL_001

LCD_DISPLAY_Controller_VHDL_002

HD44780_LCD_DISPLAY_Write-Signal_TimingOnce initialized, we can then send HEX information over its DATA_BUS to display various ASCII characters on the display area one character at a time depending on which State is shifted and thus placing a specific Binary sequence onto the LCD’s DATA_BUS logic vector.
-==== SEND the Letter “R” to Display =====-
LCD_DATA_BUS <= X”52″;      — This Hex code displays the letter R
EDIT: I have just posted a full Video Tutorial on my website for this project, and will soon have the written procedures and VHDL code posted. Check out the Blog Post link shown below to access the Instructional video.

http://www.digital-circuitry.com/Wordpress/hd44780-lcd-video-tutorial-using-vhdl-altera-de2/

You can also check out the Hitachi HD4478 LCD controller datasheet for more info on the signal control requirements and functional commands.
https://www.sparkfun.com/datasheets/LCD/HD44780.pdf
Fun Stuff!!
Cheers!
-Gerry

HD44780_LCD_DISPLAY_02