Rev. 1.10
96
November 26, 2019
Rev. 1.10
97
November 26, 2019
HT68FB240
USB Low Speed Flash MCU
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 individual sub-cycles known as
modulation cycle 0 ~ modulation 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 bit
1~bit
7 is denoted here as the DC
value. The second group which consists of bit
0 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.
Parameter
AC (0~1)
DC (Duty Cycle)
Modulation cycle i
(i=0~1)
i < AC
(DC+1)/128
i ≥ AC
DC/128
7+1 PWM Mode
PWM Register for 7+1 Mode