
S1C6P466 TECHNICAL MANUAL
EPSON
49
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (LCD Driver)
VCCHG: LCD regulated voltage switching register (FF60HD1)
Selects the reference voltage for the LCD drive voltage.
When "1" is written: VC2
When "0" is written: VC1
Reading: Valid
When "1" is written to the VCCHG register, the LCD system voltage circuit generates the LCD drive
voltage as VC2 standard. When "0" is written, it becomes VC1 standard.
In the S1C6P466, either can be selected regardless of the supply voltage level since the minimum operat-
ing voltage is 2.7 V.
The VC2 standard improves the display quality and reduces current consumption, note, however, the VC1
standard must be set in the mask ROM model (S1C63454/63458/63466) if the power supply voltage VDD
is 2.6 V or less. Pay attention when using the S1C6P466 as a development tool for these models.
At initial reset, this register is set to "0".
LDUTY0, LDUTY1: LCD drive duty switching register (FF60HD2, D3)
Selects the LCD drive duty.
Table 4.7.7.2 Drive duty setting
LDUTY1
1
0
LDUTY0
1
0
Drive duty
1/8
1/16
1/17
Common terminal used
COM0–COM7
COM0–COM15
COM0–COM16
Maximum segment number
480 (60
× 8)
960 (60
× 16)
1,020 (60
× 17)
At initial reset, this register is set to "0".
ALON: LCD all ON control register (FF61HD1)
Displays the all LCD dots ON.
When "1" is written: All LCD dots displayed
When "0" is written: Normal display
Reading: Valid
By writing "1" to the ALON register, all the LCD dots goes ON, and when "0" is written, it returns to
normal display.
This function outputs an ON waveform to the SEG terminals, and does not affect the content of the
display memory.
ALON has priority over ALOFF.
At initial reset, this register is set to "0".
ALOFF: LCD all OFF control register (FF61HD2)
Fade outs the all LCD dots.
When "1" is written: All LCD dots fade out
When "0" is written: Normal display
Reading: Valid
By writing "1" to the ALOFF register, all the LCD dots goes OFF, and when "0" is written, it returns to
normal display.
This function outputs an OFF waveform to the SEG terminals, and does not affect the content of the
display memory.
At initial reset, this register is set to "1".