ra8806 RAIO Technology Inc., ra8806 Datasheet - Page 81

• Manufacturer Part Number: ra8806
• Description: Two Layers Character/graphic Lcd Controller
• Manufacturer: RAIO Technology Inc.

Preliminary Version 1.2
RA O
i
TECHNOLOGY INC.
After writing completed font code(One byte for half size font and two bytes for full-size font), it will
takes an enough time for data to be written into the DDRAM. In the mean while no data can be read
or wrote into DDRAM. (Please refer to Section 6-8 “Interrupt and Busy”, the description of “Memory
Write Busy”). The writing time is differing from the enlargement multiplier of font size. Its calculation
formula is as follows :
Here 10% is for the flexible error consideration. Please refer to the following examples: (Estimate
the system clock is 4MHz and the tc is 250ns)
In addition to calculate writing time and delay, programmer can also check the “Busy” status to know
if font characters were written into the DDRAM. Please refer to the “ Status Register” for the
description of “Busy”.
Font enlargement multiplier Standard delay time(μS) Suggested delay time(μS)
T
T
tc : System clock period
HW : Horizontal enlargement multiplier.
VH : Vertical enlargement multiplier.
fw
fw
= ( 16*tc + 32*tc x ( HW x VH ) ) x ( 1 + 10% )
: Font Write time
1 x 1
2 x 2
3 x 3
4 x 4
Table 6-29 : Delay Time for Font Enlargement
81/184
132
12
36
76
Two Layers Character/Graphic LCD Controller
145.2
13.2
39.6
83.6
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RA8806