16 SEVEN-SEGMENT LED CONTROLLER (LEDC)
S1C17M12/M13 TECHNICAL MANUAL
Seiko Epson Corporation
16-5
(Rev. 1.2)
16.4.6 Display Data Registers
Writing data to the LEDCDAT
xy
.COM
x
[7:0] bits (or LEDCDAT
xy
.COM
y
[7:0] bits) lights the seven-segment LED
connected to COM
x
(COM
y
). The data bits from D0 to D7 of the written data correspond to a, b, c, ... g, and dp of
the seven-segment LED. Setting a data bit to 1 when the LEDCCTL.DSPON bit = 1 lights the corresponding seg-
ment and setting 0 turns it off.
Figure 16.4.6.1 shows a data setting example to display “123.45” on a five-digit seven-segment LED module.
a
g
d
dp
D7
D0 D7
D0 D7
D0 D7
D0 D7
D0
b
f
c
e
a
g
d
dp
b
f
c
e
a
g
d
dp
b
f
c
e
a
g
d
dp
b
f
c
e
a
g
d
dp
b
f
c
e
COM4
dp
0
g
0
f
0
e
0
d
0
c
1
b
1
a
0
COM3
dp
0
g
1
f
0
e
1
d
1
c
0
b
1
a
1
COM2
dp
1
g
1
f
0
e
0
d
1
c
1
b
1
a
1
COM1
dp
0
g
1
f
1
e
0
d
0
c
1
b
1
a
0
COM0
dp
0
g
1
f
1
e
0
d
1
c
1
b
0
a
1
Figure 16.4.6.1 Correspondence between Display Data and LED Segments
16.4.7 Drive Waveform
Figure 16.4.7.1 shows a drive waveform example to display the pattern shown in Figure 16.4.6.1. It assumes that
other control bits have been set as follows:
LEDCCTL.CMOFFMOD bit = 0: COM OFF state = L
LEDCCTL.SGOFFMOD bit = 1: SEG OFF state = Hi-Z
LEDCCTL.COMMOD bit = 0:
Anode common
LEDCCTL.BRITCNT[1:0] bits = 0: Maximum brightness (COM lighting period = maximum)
COM0
COM1
COM2
COM3
COM4
SEG0 (a)
SEG1 (b)
SEG2 (c)
SEG3 (d)
SEG4 (e)
SEG5 (f)
SEG6 (g)
SEG7 (dp)
V
DD
V
SS
Hi-Z
V
SS
LC
LP
Start display (DSPON = 1)
Figure 16.4.7.1 Drive Waveform Example