HT46R01A Datasheet, PDF (23/58 Pages) Holtek Semiconductor Inc – Small Package A/D Type 8-Bit OTP MCU

HT46R01A
b7
b0
P W M R e g is te r (6 + 2 ) M o d e
A C v a lu e
D C v a lu e
PWM Register for 6+2 Mode
7+1 PWM Mode
Each full PWM cycle, as it is controlled by an 8-bit PWM
register, has 256 clock periods. However, in the 7+1
PWM mode, each PWM cycle is subdivided into two indi-
vidual sub-cycles known as modulation cycle 0 ~ modula-
tion cycle 1, denoted as i in the table. Each one of these
two sub-cycles contains 128 clock cycles. In this mode, a
modulation frequency increase of two is achieved. The
8-bit PWM register 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 de-
noted 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 mod-
ulation sub-cycles is shown in the following table.
Parameter
Modulation cycle i
(i=0~1)
AC (0~1)
i<AC
i³AC
DC
(Duty Cycle)
DC+1
128
DC
128
7+1 Mode Modulation Cycle Values
The following diagram illustrates the waveforms associ-
ated with the 7+1 mode PWM operation. It is important
to note how the single PWM cycle is subdivided into 2 in-
dividual modulation cycles, numbered 0 and 1 and how
the AC value is related to the PWM value.
fS Y S /2
[P W M ] = 1 0 0
PW M
[P W M ] = 1 0 1
PW M
[P W M ] = 1 0 2
PW M
[P W M ] = 1 0 3
PW M
5 0 /1 2 8
5 0 /1 2 8
5 1 /1 2 8
5 0 /1 2 8
5 1 /1 2 8
5 1 /1 2 8
5 2 /1 2 8
P W M m o d u la tio n p e r io d : 1 2 8 /fS Y S
M o d u la tio n c y c le 0
P W M c y c le : 2 5 6 /fS Y S
5 1 /1 2 8
M o d u la tio n c y c le 1
7+1 PWM Mode
5 0 /1 2 8
5 1 /1 2 8
5 1 /1 2 8
5 2 /1 2 8
M o d u la tio n c y c le 0
b7
b0
P W M R e g is te r (7 + 1 ) M o d e
A C v a lu e
D C v a lu e
PWM Register for 7+1 Mode
Rev. 1.10
23
August 13, 2008