INTRODUCTION
Graphic LCDs are nice to play
with. I have a Powertip PG 12864-D . It is a 128*64 graphics LCD with
two Samsung KS0108 controllers (one for the left and the other for
the right half of the display). So, the
info presented will cover
LCDs with KS0108 and compatible controllers (Hitachi HD61202 and others,if
any).
If you have ever worked with
HD44780 controlled character type LCDs, you will find the KS0108 easy
to work with. They have a similar interface, and you may easily change
your HD44780 code to suit the KS0108. I will assume that you know
how the HD44780 interface works. This means that basic things like
reading from/writing to DDRAM, checking the busy flag, and etc. will
not be covered here. You may find such info elsewhere on my LCD
pages.
You can think of a 128*64 LCD
as a 1024 bayt memory , every bit of which is visible. The display
is split logically in half. It contains two controllers with controller#1(Chipselect1)controlling
the left half of the display and controller#2 (Chipselect2) controlling
the right half. Each controller must be addressed independently. Each
half consists of 8 horizontal pages which are 8 bits (1 byte) high.
The page addresses, 0-7, specify one of the 8 pages. That is illustrated
in the drawing below.