23 LCD DRIVER (LCD)
S1C17624/604/622/602/621 TECHNICAL MANUAL
Seiko Epson Corporation
23-1
LCD Driver (LCD)23
LCD Module Overview23.1
The S1C17624/622 and S1C17604/602/621 include a dot-matrix LCD driver capable of driving an LCD panel with
up to 416 segments (52 segments × 8 commons) and 288 segments (36 segments × 8 commons), respectively.
The main features of the LCD driver are listed below.
• Number of SEG and COM outputs S1C17624/622: 52 SEG × 8 COM or 56 SEG × 4/3/2/1 COM
S1C1760
4/602/621: 36 SEG × 8 COM or 40 SEG × 4/3/2/1 COM
• Drive bias 1/3 bias (fixed)
• Display data RAM S1C17624/622: 56 bytes
S1C17604/602/621: 40 bytes
• Frame frequency configuration Adjustable with a four-bit counter
• LCD display mode Normal display mode
All on mode
All off mode
Inverted display mode
• COM and SEG pins Supports inverting memory bit assignment to the COM and SEG pins.
• LCD contrast adj
ustment Selectable from among 16 values
• Other functions LFRO signal output, frame interrupt
Figure 23.1.1 shows the LCD driver and drive power supply configuration.
COMx
SEGx
LFRO
LCLK
OSC1
HSCLK
Divider
(1/32–1/512)
Gate
LC[3:0]
DSPAR
DSPC[1:0]
LDUTY[2:0]
FRMCNT[1:0]
DSPREV
SEGREV
COMREV
To ITC
Frame interrupt request
VC1–VC3
LCD system
voltage regulator
LCD contrast
adjustment
circuit
Display memory
Driver
control circuit
Clock
control circuit
FRMIE
Interrupt
control circuit
Power supply circuit
LCD driver
LHVLDVCSEL
LCKENLCKDV[2:0] LCKSRC
1.1 LCD Driver and Driver Power Supply ConfigurationFigure 23.
LCD Power Supply23.2
The LCD drive voltages VC1 to VC3 are generated by the on-chip LCD voltage regulator. No external power supply
is needed. For more information on the LCD power supply, see the “Power Supply” chapter.
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