S1D13700F01 Epson Electronics America, Inc., S1D13700F01 Datasheet - Page 84

• Manufacturer Part Number: S1D13700F01
• Description: Embedded Memory Graphics Lcd Controller
• Manufacturer: Epson Electronics America, Inc.

Page 84
12.3 Cursor Control
12.3.1 Cursor Write Register Function
12.3.2 Cursor Movement
12.3.3 Cursor Display Layers
S1D13700F01
X42A-A-002-04
Note
The Cursor Write register (REG[1Ch] - REG[1Dh]) functions as both the displayed cursor
position address register and, in indirect addressing mode, the display memory access
address register. When accessing display memory outside the actual visible screen
memory, the Cursor Write register should be saved before accessing the memory and then
restored after the memory access is complete. This is done to prevent the cursor from
visibly disappearing outside the display area.
On each memory access, the Cursor Write register (REG[1Ch] - REG[1Dh]) is changed by
the amount specified by the CSRDIR command (see REG[17h] bits 1-0) which automati-
cally moves the cursor to the desired location.
Although the S1D13700F01 can display up to three layers, the cursor is displayed in only
one of these layers. For a two layer configuration (REG[18h] bit 4 = 0), the cursor is
displayed in the first layer (L1). For a three layer configuration (REG[18h] bit 4 = 1), the
cursor is displayed in the third layer (L3).
The cursor is not displayed if the address is moved outside of the memory for its layer. If it
is necessary to display the cursor in a layer other than the present one, the layers may be
swapped, or the cursor layer can be moved within the display memory.
The cursor may disappear from the display if the cursor address remains outside the dis-
played screen memory for more than a few hundred milliseconds.
REG[1Ch], REG[1Dh]
Figure 12-8 Cursor Addressing
Revision 4.05
Cursor display
address register
Address pointer
Epson Research and Development
Hardware Functional Specification
Vancouver Design Center
Issue Date: 2005/12/13