M30222 Datasheet, PDF (150/237 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

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Specifications in this manual are tentative and subject to change
MITSUBISHI MICROCOMPUTERS
M30222 Group
Rev. G
LCD Drive Control Circuit
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Bias Control and Applied Voltage to LCD Power Input Pins
To the LCD power input pins (VL1 to VL3), apply the voltage shown in Table 1.46 according to the bias value. Select
a bias value by the bias control bit (bit 2 of the address 012016). Figure 1.120 is an example of circuit at each bias.
Table 1.46. Bias control and applied voltage to VL1 to VL3
Bias value Voltage value
1/3 bias
VL3 = VLCD
VL2 = 2/3 VLCD
VL1 = 1/3 VLCD
1/2 bias
VL3 - VLCD
VL2 =VL1= 1/2VLCD
Note: VLCD is the maximum value of supplied
voltage for the LCD panel.
VL3
VL2
C2
C1
VL1
Contrast
control
VL3
R1
VL2
C2
open
R2
C1
open
VL1
R3
Contrast
control
VL3
R4
VL2
C2
open
C1
open
VL1
R5
VL3
VL2
C2
open
C1
open
VL1
1/3 bias when using
voltage multiplier (VL1<= 2.1V)
R1=R2=R3
1/3 bias when not
using voltage multiplier
Fig. 1.120. Example of circuit at each bias
1/2 bias
R4=R5
When selecting LCDRAM data output
(not using LCD panel)
Common Pin and Duty Control
The common pins (COM0 to COM3) to be used are determined by the required duty. Table 1.47shows
the duty control and the common pins used. Select duty ratio by the duty ratio select bits (bits 0 and
1 of address 012016).
Table 1.47. Duty ratio control and common pins used
Duty ratio
Daily ratio
select bit
Bit 1 Bit 0
Common pins used
2
0
1
COM0, COM1 (Note 1)
3
1
0
COM0 to COM2 (Note 2)
4
1
1
COM0 to COM3
Note 1: COM2 and COM3 are open.
Note 2: COM 3 is open.
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