ra8835a RAIO Technology Inc., ra8835a Datasheet - Page 38

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

RAiO TECHNOLOGY INC.
Version 1.0
7-6 Oscillator Circuit
7-7 Status Flag
The RA8835A series incorporates an oscillator circuit. A stable oscillator can be constructed simply by
connecting an AT-cut crystal and two capacitors to XG and XD, as shown in the figure below. If the
oscillator frequency is increased, CD and CG should be decreased proportionally. Note that the circuit
board lines to XG and XD must be as short as possible to prevent wiring capacitance from changing
the oscillator frequency or increasing the power consumption.
The RA8835A series has a single bit status flag.
D6: X line standby
The D6 status flag is HIGH for the TC/R-C/R cycles at the end of each line where the RA8835A series
is not reading the display memory. The microprocessor may use this period to update display memory
without affecting the display, however it is recommended that the display be turned off when refreshing
the whole display.
XSCL
LP
Figure 7-6: C/R to TC/R Time Difference
Figure 7-4: Crystal Oscillator
Figure 7-5: Status Flag
tm
XG
C
G
RA8835
38/88
XD
t
TC/R
C
D
Load impedance =700? (max)
t
C/R
C
C
D
G
=3 to 20 pF
=2 to 18 pF
Dot Matrix LCD Controller
RA8835A
www.raio.com.tw