ra8835a RAIO Technology Inc., ra8835a Datasheet - Page 57

• Manufacturer Part Number: ra8835a
• Description: Dot Matrix Lcd Controller
• Manufacturer: RAIO Technology Inc.

8. Application Notes
RAiO TECHNOLOGY INC.
Version 1.0
8-1 Initialization Parameters
8-1-1 System Set Instruction and Parameters
The parameters for the initialization commands must be determined first. Square brackets around a
parameter name indicate the number represented by the parameter, rather than the value written to the
parameter register. For example, [FX] = FX + 1.
◎ FX
The horizontal character field size is determined from the horizontal display size in pixels [VD] and the
number of characters per line [VC].
◎ C/R
C/R can be determined from VC and FX.
Where RND(x) denotes ´ rounded up to the next highest integer. [C/R] is the number of bytes per line,
not the number of characters.
◎ TC/R
TC/R must satisfy the condition
◎ f
Once TC/R has been set, the frame frequency, f
The lower limit on the oscillator frequency f
◎ If no standard crystal close to the calculated value of f
◎ Symptoms of an incorrect TC/R setting are listed below. If any of these appears, check the value of
• Vertical scanning halts and a high-contrast horizontal line appears.
• All pixels are on or off.
• The LP output signal is absent or corrupted.
• The display is unstable.
TC/R and modify it if necessary.
OSC
used and the value of TC/R revised using the above equation.
[C/R]
f
[VD]
[VC]
and f
OSC
≤
=
≥
FR
[FX]
RND(
(
[TC/R]
[FX]
8
×
)
×
9
[VC]
+
1)
×
[L/F]
[TC/R]
×
f
≥
FR
[C/R]
OSC
57/88
+
4
is given by:
.
FR
, and lines per frame [L/F] will also have been set.
OSC
exists, a higher frequency crystal can be
Dot Matrix LCD Controller
RA8835A
www.raio.com.tw