ra8835 Topway Display, ra8835 Datasheet - Page 37

• Manufacturer Part Number: ra8835
• Description: Dot Matrix Lcd Controller
• Manufacturer: Topway Display

RA8835
Version 1.7
Dot Matrix LCD Controller
Read Status Flag
NO
D6=0?
Yes
Data Input
Data Input?
Yes
Figure 7-7: Flowchart for Busy Flag Checking
• Precaution on the write timing to VRAM
LP
XSCL
5x9xtosc
Display memeory write
timex9xtosc
The allowable writing duration is since “5 x 9 x t
” has elapsed (t
= 1/f
: a cycle of the oscillation
OSC
OSC
OSC
frequency) from the positive going edge of LP up to {(TCR) – (C/R) – 7} x 9 x t
.
OSC
Currently employed D6 status flag reading method does not identify the timing when the read D6 =
Low took place. Thus, negative going edge of LP should be used as the interrupt signal when
implementing the writing in above timing. If you try to access the display memory in other timing than
the above, flickering of the display screen will result.
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