23 lCD DRiVeR (lCD)
S1C17624/604/622/602/621 TeChniCal Manual
Seiko epson Corporation
23-1
LCD Driver (LCD)
23
lCD Module Overview
23.1
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
S1C17604/602/621: 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 adjustment
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.
COM
x
SEG
x
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
V
C1
–V
C3
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
LHVLD
VCSEL
LCKEN
LCKDV[2:0]
LCKSRC
1.1 LCD Driver and Driver Power Supply Configuration
Figure 23.
lCD Power Supply
23.2
The LCD drive voltages V
C1
to V
C3
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.