The 16x2 Character LCDs have their own limitations; they can only display characters of certain dimensions. The Graphical LCDs are
thus used to display customized characters and images. The Graphical
LCDs find use in many applications; they are used in video games, mobile
phones, lifts etc. as display units.
Various graphical LCDs are available in the market with different sizes. Here JHD12864E Graphical LCD has been explained. This LCD has a display format of 128x64 dots and has yellow-green colour backlight. Each LCD needs a controller to execute its internal operations. This LCD uses two KS0108 controllers.
The 128x64 LCD is
divided into two equal halves with each half being controlled by a
separate KS0108 controller. Such LCDs (using KS0108 controller) involve
paging scheme, i.e., whole LCD is divided equally into pages. The paging
scheme of the graphical LCD can be easily understood from the following table.
1. 128x64 LCD implies 128 columns and 64 rows. In total there are (128x64 = 1024) pixels.
LCD is divided equally into two halves. Each half is controlled by a
separate controller and consists of 8 pages. In above diagram, CS stands
for Controller Select.
page consists of 8 rows and 64 columns. So two horizontal pages make
128 (64x2) columns and 8 vertical pages make 64 rows (8x8).