RA8835A
Version 1.0
Dot Matrix LCD Controller
7-13-5 Scroll Units
Table-20B: Scroll Units
Mode
Text
Graphics
Vertical
Characters
Pixels
Horizontal
Pixels or
characters
Pixels
Note that in a divided screen, each block cannot be independently scrolled horizontally in pixel
units.
7-14 CG Characteristics
7-14-1 Internal Character Generator
The internal character generator is recommended for minimum system configurations containing
a RA8835A series, display RAM, LCD panel, single-chip microprocessor and power supply. Since
the internal character generator uses a CMOS mask ROM, it is also recommended for low-power
applications.
• 5 x 7-pixel font (See Section 18.)
• 160 JIS standard characters
• Can be mixed with character generator RAM (maximum of 64 CG RAM characters)
• Can be automatically spaced out up to 8 x 16 pixels
7-14-2 External Character Generator ROM
The external CG ROM can be used when fonts other than those in the internal ROM are needed.
Data is stored in the external ROM in the same format used in the internal ROM. (See Section
11-4)
• Up to 8 x 8-pixel characters (M2 = 0) or 8 x 16-pixel characters (M2 = 1)
• Up to 256 characters (192 if used together with the internal ROM)
• Mapped into the display memory address space at F000H to F7FFH (M2 = 0) or F000H to
FFFFH (M2 = 1)
• Characters can be up to 8 x 16-pixels; however, excess bits must be set to zero.
7-14-3 Character Generator RAM
The user can freely use the character generator RAM for storing graphics characters. The
character generator RAM can be mapped by the microprocessor anywhere in display memory,
allowing effective use of unused address space.
• Up to 8 x 8-pixel characters (M2 = 0) or 8 x 16 characters (M2 = 1)
• Up to 256 characters if mapped at F000H to FFFFH (64 if used together with character
generator ROM)
• Can be mapped anywhere in display memory address space if used with the character
generator ROM
• Mapped into the display memory address space at F000H to F7FFH if not used with the
character generator ROM (more than 64 characters are in the CG RAM). Set SAG0 to
F000H and M1 to zero when defining characters number 193 upwards.
RAiO TECHNOLOGY INC.
www.raio.com.tw
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RAIO [ RAIO TECHNOLOGY INC. ]
