RA8835A
Version 1.0
Dot Matrix LCD Controller
7-11 Cursor Control
7-11-1 Cursor Register Function
The RA8835A series cursor address register functions as both the displayed cursor position
address register and the display memory access address register. When accessing display
memory outside the actual screen memory, the address register must be saved before accessing
the memory and restored after memory access is complete.
Figure 7-17: Cursor Addressing
Note that the cursor may disappear from the display if the cursor address remains outside the
displayed screen memory for more than a few hundred milliseconds.
7-11-2 Cursor Movement
On each memory access, the cursor address register changes by the amount previously
specified with CSRDIR, automatically moving the cursor to the desired location.
7-11-3 Cursor Display Layers
Although the RA8835A series can display up to three layers, the cursor is displayed in only one of
these layers: Two-layer configuration: First layer (L1) Three-layer configuration: Third layer (L3)
The cursor will not be displayed if it is moved outside the memory for its layer. Layers may be
swapped or the cursor layer moved within the display memory if it is necessary to display the
cursor on a layer other than the present cursor layer.
Although the cursor is normally displayed for character data, the RA8835A series may also
display a dummy cursor for graphical characters. This is only possible if the graphics screen is
displayed, the text screen is turned off and the microprocessor generates the cursor control
address.
Figure 7-18: Cursor Display Layers
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