ra8806 RAIO Technology Inc., ra8806 Datasheet - Page 39

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

Preliminary Version 1.2
RAiO
TECHNOLOGY INC.
In which the EXT_MD means extension mode is set or not, if REG[12h] Bit[6:4] = 110b/111b,
EXT_MD = 1, or EXT_MD = 0. The “XCK_PRD” is one clock period of XCK. The XCK frequency is
base on the system clock. It depends on the setting of Bit[3:2] of REG[MISC]. As to the Frame time
and frame rate calculation. It would be:
For example, when panel size is set to 320x240, system clock frequency is 8MHz, REG[MISC]
Bit[3:2] = 10b, LCD driver data bus width is 4-bits, what the frame rate would be?
The System Clock(CLK) is 8MHz, and REG[MISC] Bit[3:2] = 10b
is 250ns.
If the ITCR = A0h(160 in decimal):
The COM number is 240, so the frame period is:
And the frame rate is:
We can see the effect that the ITCR setting to the corresponding frame rate. So we can use it to
adjust the frame rate. Please refer to Appendix B - the Table B-1 ~ Table B-3. In those tables, we
show some Frame Rate setting for difference resolution, system clock. But note the display quality is
also depends on the module design and the material of liquid crystal.
MISC
ITCR
Reg.
COM_PRD = ((SEG_NO/LD_WIDTH) x (1 + EXT_MD)) ＋ ITCR ) x XCK_PRD
FRM_PRD = COM_PRD x COM#
FRM_Rate = 1 / FRM_PRD
XCK_PRD = 1 / (CLK/2) = 1/4MHz = 250ns
COM_PRD = ( 320 / 4 ＋ ITCR) x XCK_PRD = (80+ ITCR) x 250(ns)
COM_PRD = (80+160) x 250ns = 240 x 250ns = 60µs
FRM_PRD = 60µs x 240 = 14.4 ms
Frame Rate = 1 / 14.4 ms = 69.4 Hz
Bit_Num
Bit [7:0]
Bit [3:2]
And
Define the idle time during the LP peer-to-
peer time.
Select the clock frequency of XCK.
Table 6-8
39/184
Description
Two Layers Character/Graphic LCD Controller
XCK = CLK/2, so the XCK_PRD
Reference
REG[90h]
REG[01h]
www.raio.com.tw
RA8806