HT46F46E/HT46F47E/HT46F48E/HT46F49E
S
Y
S
[
P
W
M
]
=
1
0
0
P
W
M
2
5
/
6
4
2
5
/
6
4
2
5
/
6
4
2
5
/
6
4
2
2
2
2
5
6
6
6
/
/
/
/
6
6
6
6
4
4
4
4
[
P
W
M
]
=
1
0
1
P
W
M
2
6
/
6
4
2
5
/
6
4
2
2
2
5
5
6
/
/
/
6
6
6
4
4
4
2
5
/
6
4
[
P
W
M
]
=
1
0
2
P
W
M
2
6
/
6
4
2
6
/
6
4
2
5
/
6
4
[
P
W
M
]
=
1
0
3
P
W
M
2
6
/
6
4
2
6
/
6
4
2
5
/
6
4
P
W
M
m
o
d
u
l
a
t
i
o
n
p
e
r
i
o
d
:
6
4
/
f
M
o
d
u
l
a
t
i
o
n
c
y
c
l
e
0
M
o
d
u
l
a
t
i
o
n
c
y
c
l
e
1
M
o
d
u
l
a
t
i
o
n
c
y
c
l
e
2
M
o
d
u
l
a
t
i
o
n
c
y
c
l
e
3
M
o
d
u
l
a
t
i
o
n
c
y
c
l
e
0
P
W
M
c
y
c
l
e
:
2
5
6
/
f
6+2 PWM Mode
b
7
b
0
P
W
M
,
P
W
M
0
,
P
W
M
1
R
e
g
i
s
t
e
r
s
(
6
+
2
)
M
o
d
e
A
D
C
v
a
l
u
u
e
C
v
a
l
e
6+2 Mode Pulse Width Modulation Register
7+1 PWM Mode
DC
Parameter
AC (0~1)
i<AC
(Duty Cycle)
Each full PWM cycle, as it is controlled by an 8-bit PWM,
PWM0 or PWM1 register, has 256 clock periods. How-
ever, in the 7+1 PWM mode, each PWM cycle is subdi-
vided into two individual sub-cycles known as modulation
cycle 0 ~ modulation cycle 1, denoted as ²i² in the table.
Each one of these two sub-cycles contains 128 clock cy-
cles. In this mode, a modulation frequency increase of
two is achieved. The 8-bit PWM, PWM0 or PWM1 regis-
ter value, which represents the overall duty cycle of the
PWM waveform, is divided into two groups. The first
group which consists of bit1~bit7 is denoted here as the
DC value. The second group which consists of bit0 is
known as the AC value. In the 7+1 PWM mode, the duty
cycle value of each of the two modulation sub-cycles is
shown in the following table.
DC+1
128
Modulation cycle i
(i=0~1)
DC
i³AC
128
7+1 Mode Modulation Cycle Values
The following diagram illustrates the waveforms associ-
ated with the 7+1 mode of PWM operation. It is impor-
tant to note how the single PWM cycle is subdivided into
2 individual modulation cycles, numbered 0 and 1 and
how the AC value is related to the PWM value.
S
Y
S
[
P
W
M
]
=
1
0
0
P
W
M
5
0
/
1
2
8
5
0
/
1
2
8
5
0
/
1
2
8
[
P
W
M
]
=
1
0
1
P
W
M
5
1
/
1
2
8
5
0
/
1
2
8
5
1
/
1
2
8
[
P
W
M
]
=
1
0
2
P
W
M
5
1
/
1
2
8
5
1
/
1
2
8
5
1
/
1
2
8
[
P
W
M
]
=
1
0
3
P
W
M
5
1
/
1
2
8
5
2
/
1
2
8
5
2
/
1
2
8
P
W
M
m
o
d
u
l
a
t
i
o
n
p
e
r
i
o
d
:
1
2
8
/
f
M
o
d
u
l
a
t
i
o
n
c
y
c
l
e
0
M
o
d
u
l
a
t
i
o
n
c
y
c
l
e
1
M
o
d
u
l
a
t
i
o
n
c
y
c
l
e
0
P
W
M
c
y
c
l
e
:
2
5
6
/
f
7+1 PWM Mode
Rev. 1.31
36
January 9, 2009
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
