HT45RM03 Holtek Semiconductor, HT45RM03 Datasheet - Page 19

• Manufacturer Part Number: HT45RM03
• Description: Brushless DC Motor Type 8-Bit OTP MCU
• Manufacturer: Holtek Semiconductor

It is recommended that unused or not bonded out I/O lines should be set as output pins by software instruction to avoid
consuming power under input floating state.
PWM
The microcontroller is provided with three channel PWM
and Complementary PWM output shared with
PC0~PC5, named PWM0~PWM2 and PWM0~PWM2,
with standard 10 bits output, (9+1), (8+2), or (7+3) mode
(configuration option determined). The PWM function
provides output with a varied frequency and duty cycle
by setting particular values into PWMC and PWML,
PWMH registers. The frequency source of the PWM
counter comes from f
chosen from f
The PWM channel has their data registers denoted as
PWMH (1AH) and PWML (1BH). These two registers
define the PWM output duty cycle. The PWMH is an
8-bit register, and it is a higher-order data register, the
PWML is a lower-order register and two bits (bit1~bit0)
are provided in this register. The PWM duty cycle is
specified by writing to these two PWM data registers,
writing PWML will only put the written data to an internal
lower-order byte buffer (2-bit) and writing PWMH will
transfer the specified data and the contents of the
lower-order byte buffer to PWMH and PWML registers,
respectively. Once the PC0~PC5 is selected as the
PWM and Complementary PWM outputs and the output
Rev. 1.00
SYS
~f
SYS
PWM
/8 (software option determined).
. The f
PWM
clock source can be
Input/Output Ports
19
function of PC0~PC5 is enabled (PCC.0 ~ PCC.5 = 0 ),
writing 1 to PC0, PC2 and PC4 register will enable the
PWM output function and writing 0 will force the PC0,
PC2 and PC4 stay at inactive state ( 0 if the PWMLEV
option is select active high). Writing 1 to PC1, PC3 and
PC5 register will enable the Complementary PWM out-
put function and writing 0 will force the PC1, PC3 and
PC5 stay at inactive state ( 0 if the PWMCLEV option is
select active high).
The PWM clock source can be chosen form f
(dependent on software option). When the f
source is selected from f
provides with a fixed frequency output (f
(f
(9+1), (8+2) and (7+3) output mode, it s duty cycle is de-
cided by writing to the PWMH and PWML registers, the
waveform of PWMH output is as shown.
When the PWM output function is enabled (writing 1 to
PC0~PC5 register, when PWM and Complementary
PWM output function is enable) and the f
source is selected from PWM prescaler, the value of
PWMPSC0~PWMPSC1, PWML and PWMH can be
written to at any time even if the PWM and Complemen-
tary PWM output is running.
SYS
/8192). The PWM output provides standard 10-bit,
SYS
~f
SYS
/8, the PWM function
HT45RM03
January 11, 2007
SYS
SYS
PWM
PWM
~f
/1024~
SYS
clock
clock
/8