ra8806 RAIO Technology Inc., ra8806 Datasheet - Page 104

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

Preliminary Version 1.2
RAiO
6-15 Eliminating Flicker Mode
TECHNOLOGY INC.
RA8806 also provides “Eliminating Flicker Mode” in order to eliminate display errors at scan/MPU
confliction. When the scan logic is processing scan task and at the same time the DDRAM is accessed
by the MPU, the scan data will force to get a wrong one and may experience side effects such as
“flicker”. When the flicker is too much, it will infect the display effect.
Therefore, RA8806 is designed to disable scan logic when MPU is accessing the DDRAM. And after it is
completed, the scan logic active again. The “Eliminating Flicker Mode” separate Write and Read
operating therefore no confliction will happen between scan logic and MPU cycle. That is, no data will
lose. Ideally, it will have great improvement at display effect.
In real application, sometimes the cycle time that MPU writes data will be different(font write and
memory clear), although it accesses the RA8806 periodly. On the other hand, the display performance
is still limited when operating under the eliminating-flicker mode in some conditions. The limits are :
Additionly, RA8806 also supply a method to eliminate flicker by check status. By check the status bit-
6(SCAN BUSY), user can know whether can access memory that doesn’t conflict the scan data period.
The application figure is below :
(1) The eliminating-flicker mode is suggested to operate under the graphic mode(bit-7 of register[01h]
(2) Please disable eliminating-flicker function before the memory clear mode. After the memory clear
is setting 1).
function is finished, then the eliminating-flicker function could be enable again.
MISC
Reg.
Bit_Num
Bit 7
Figure 6-74 : Eliminating Flicker Mode
The LCD Driver-Scan will auto-pending
when busy.
Table 6-38
Description
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Two Layers Character/Graphic LCD Controller
Reference
REG[01h]
www.raio.com.tw
RA8806