
S1C88348/317/316/308 TECHNICAL HARDWARE
EPSON
I-117
5 PERIPHERAL CIRCUITS AND THEIR OPERATION (LCD Controller)
5.12.4 LCD driver
The maximum number of dots changes according
to the drive duty selection.
When 1/32 duty is selected, the combined com-
mon/segment output terminal is switched to the
common terminal. An LCD panel with 51 segments
× 32 commons (maximum 1,632 dots) in the
S1C88348/317/316 and 41 segments
× 32 commons
(maximum 1,312 dots) in the S1C88308 can be
driven.
When 1/16 duty is selected, the combined com-
mon/segment output terminal is switched to the
segment terminal. An LCD panel with 67 segments
× 16 commons (maximum 1,072 dots) in the
S1C88348/317/316 and 57 segments
× 16 commons
(maximum 912 dots) in the S1C88308 can be driven.
When 1/8 duty is selected, the combined common/
segment output terminal is switched to the segment
terminal as when 1/16 duty is selected. An LCD
panel with 67 segments
× 8 commons (maximum
536 dots) in the S1C88348/317/316 and 57 seg-
ments
× 8 commons (maximum 456 dots) in the
S1C88308 can be driven. Furthermore, when 1/8
duty is selected, terminals COM8–COM15 become
invalid, in that they always output an OFF signal.
Table 5.12.4.1 shows the correspondence between
the drive duty and the maximum number of
displaying dots.
The drive bias is 1/5 (five potentials, VC1–VC5) for
any one of the 1/32, 1/16 and 1/8 duties. The
respective drive waveforms are shown in Figures
5.12.4.1–5.12.4.3.
Table 5.12.4.1 Correspondence between drive duty and maximum number of displaying dots
Model
name
S1C88348
S1C88317
S1C88316
Mask option
1/32 & 1/16 duty
1/8 duty
1/32 & 1/16 duty
1/8 duty
LDUTY
0
1
×
0
1
×
Duty
1/32
1/16
1/8
1/32
1/16
1/8
Common
terminal
COM0–COM31
COM0–COM15
COM0–COM7
COM0–COM31
COM0–COM15
COM0–COM7
Segment
terminal
SEG0–SEG50
SEG0–SEG66
SEG0–SEG40
SEG0–SEG56
Maximum number
of display dots
1,632 dots
1,072 dots
536 dots
1,312 dots
912 dots
456 dots
S1C88308