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Epson Research and Development
Vancouver Design Center
8 Hardware Cursor/Ink Layer
8.1 Introduction
The S1D13506 supports either a Hardware Cursor or an Ink Layer for the LCD, and either
a Hardware Cursor or an Ink Layer for the CRT/TV. The LCD and CRT/TV are supported
independently, so it is possible to select combinations such as a Hardware Cursor on the
LCD and an Ink Layer on the CRT/TV.
A Hardware Cursor improves video throughput in graphical operating systems by off-
loading much of the work typically assigned to software. For example, consider the actions
which must be performed when the user moves the mouse. On a system without hardware
support, the operating system must restore the area under the current cursor position, save
the area under the new location, and finally draw the cursor shape. Contrast that with the
hardware assisted system where the operating system must simply update the cursor X and
cursor Y position registers.
An Ink Layer is designed to support stylus or pen input. Without an ink layer, the operating
system must save the area of the display buffer (possibly all) where pen input is to occur.
After the system recognizes the characters entered, the display would have to be restored
and the characters redrawn in a system font. When an Ink Layer is present, the stylus path
is drawn in the Ink Layer where it overlays the displayed image. After character recognition
finishes the display is updated with the new characters and the ink layer is simply cleared.
Saving and restoring the display data is not required providing faster throughput.
The S1D13506 Hardware Cursor/Ink Layer supports a 2 bpp (four color) overlay image.
Two of the available colors are transparent and invert. The remaining two colors are user
definable.
The Hardware Cursor uses many of the same registers as the Ink Layer. Additionally, the
cursor has positional registers for movement. The cursor resolution is 64x64 at a color
depth of 2 bpp. The Ink Layer resolution is the width of the display by the height of the
display at a color depth of 2 bpp. Both the Hardware Cursor and the Ink Layer use the same
pixel values to select colors. The Hardware Cursor requires 1024 bytes of display buffer
and the Ink Layer requires (display width x display height ÷ 4) bytes of display buffer.
S1D13506
X25B-G-003-03
Programming Notes and Examples
Issue Date: 01/02/06
EPSON [ EPSON COMPANY ]
