GMS81508A Datasheet, PDF (38/91 Pages) Hynix Semiconductor – USERS MANUAL

GMS81508/16
2.10. PWM
PWM(Pulse Width Modulation) has a 8-bit resolution and the PS8,PS9,PS10,PS11 of the prescaler
can be selected as input clock PWM.
Internal Data Bus
PS8
PS9
PS10
PS11
MUX
PWMR0
Overflow _S
Comparator
Q
R
Counter
Polarity
PWM0
P1CK1 P1CK0 P0CK1 P0CK0 EN1 EN0 POL1 POL0
PWMCR
PS8
PS9
PS10
PS11
MUX
Internal Data Bus
Counter
Overflow _S
Comparator
Q
R
PWMR1
Polarity
PWM1
2.10.1. Controls of PWM
The input clock is selected by PWM Control Register (PWMCR), and the width of pulse is
determined by the PWM Register (PWMR).
The pulse period according to input clock are as follows.
Input clock
 PS8 (32 )
 PS9 (64 )
 PS10 (128 )
 PS11 (256 )
PWM Period
 8,192
 16,384
 32,768
 65,536
Bit2 (EN0) and bit3 (EN1) of PWM control Register (PWMCR) determine the operation channel of
PWM. When EN0=0 and EN1=0, PWM does not executed. The EN0 and EN1 are Enable bit of
PWM channel 0 and channel 1 respectively. When EN0=1, PWM channel0 executes. When EN1=1,
PWM channel1 executes.
POLO and POL1 are a polarity control bit of channel0 and channel1. When they are 0, LOW
active. When 1, HIGH active. PWMCR becomes "00h" in reset state.
33