Overview - Oki ML63611 User Manual

13. LCD Driver (LCD)
13.1

Overview

The ML63611 has built in it a segment type LCD driver (LCD) with 64 outputs.
The LCD driver section consists of a segment register, the display control register 0 (DSPCON0), the display
control register 1 (DSPCON1), the display contrast register (DSPCNT), the LCD driver circuits for 64 outputs,
and the bias generator circuit (BIAS).
The OPTION B and OPTION D use a voltage regulator circuit for the LCD, but the OPTION A and OPTION C
do not use a voltage regulator.
The segment register is a register that can be used by selecting with the mask option. Even when using the
segment register as the data area, it is necessary to specify that segment register in the mask option table. The
pins of the part of the segment register used as the data area will still be outputting the segment waveforms, and
hence should be left open. The allocation of the segment drivers of the different bits of the segment register can
be specified freely by the mask option. For details of the mask option settings, refer to Section 1.3, "Mask
Options" and the "MOGTOOL Mask Option Generator User's Manual".
DSPCON0 is the register for selecting the bias mode, power down mode, all-ON mode, and the display mode.
DSPCON1 is the register for selecting the duty ratio (1/1 to 1/4).
DSPCNT is the register for selecting the contrast value. However, this will not be effective in the OPTION A
and OPTION C.
The LCD driver circuits consist of the segment driver circuits and the common driver circuits, with a total of 64
outputs L0 to L63. Among these driver circuits, a total of 64 circuits, L0 to L3 and L36 to L39, can be selected
to be COM pins (COM1 to COM4) by making mask option settings for each bit. In addition, the four bits L32 to
L35 can be selected to form an output port in 4-bit unit. The relationship among the duty ratio, bias value, and
the maximum number of segments is as follows:
During 1/4 duty and 1/3 bias: 240 segments
During 1/2 duty and 1/2 bias: 124 segments
The OPTION B and OPTION D use a voltage regulator circuit (V/R3) that generates the bias generation reference
voltage for the LCD driver. BIAS is a circuit that multiplies the output voltage (V
generates the different bias voltages when external capacitors are connected.
The OPTION A and OPTION C do not use the voltage regulator circuit (V/R3) that generates the bias generation
reference voltage for the LCD driver. BIAS is a circuit that multiplies the power supply voltage and generates
the different bias voltages when external capacitors are connected. In the OPTION A, short the pin V
in the OPTION C, short the pin V
!
Note:
The OPTION B and OPTION D can keep the display density of the LCD panel constant even if the battery voltage
decreases, while in the case of the OPTION A and OPTION C the display density thins down as the battery voltage
decreases.
OPTION A (C): 1.5 V (3.0 V), Without regulator
circuit for LCD bias
to V .
DD2 DD
13 – 1
ML63611 User's Manual
Chapter 13 LCD Driver (LCD)
= 0.95 V) of V/R3 and
DD1
OPTION B (D): 1.5 V (3.0 V), With regulator
circuit for LCD bias
to V ;
DD1 DD