2*16 CHARACTER DISPLAY : This LCD display can acquire 40 characters in a line but only 16 are visible at a time although others can be made visible by shifting the characters. The very general LCD's has 16 pins or control lines through which bytes are R/W and controlled.
So, some of the important characteristics of HD44780 are discussed here :
DISPLAY DATA RAM (DDRAM): The memory area within the module contains the 8bit address of the element of the 2*16 display matrix so whatever character code you write is written on to the DDRAM.
CHARACTER GENERATOR ROM (CGROM): The question must be raised that even if you know where to store your 8bit coded input, still the generation of the character from a given code must be done and hence CGROM is described here. CGROM actually does the generation of the character into 5*8 dot or 5*10 dot display from the code you have given. So, CGROM will convert 00110000 into a 5*8 dot ZERO.
CHARACTER GENERATOR RAM(CGRAM): This might be very interesting memory area for the LCD users because this segment allows you to generate your own characters and you even can generate your own Facebook smileys into your LCD but this one is for an experienced user , so we will make use of it later on sometime may be.
FLAGS & REGISTERS : The most common flag that is used is busy flag and indicates the status of the process going(set for busy & vice-versa). Busy flag is read only when command and read is set & also MSB of the data pin (d7) acts as BF.
The 2 important registers INSTRUCTION REGISTER & DATA REGISTER and as the name suggests these two 8bit registers are for R/W of the command & data.
pin structure of the HD44780 controlled LCD
THIS POST INCLUDED THE BRIEF INTRODUCTION OF THE HD44780 CONTROLLED LCD & NEXT WILL BE DISCUSSING ABOUT THE BASICS OF ATMEGA8 AND FINALLY COMBINING THE TWO TO MAKE SOME INTERESTING OUTPUTS
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