Samsung S3F84A5 Manuale Utente

N

Y

Decrease PWM duty cycle

Start

PWMEX>=100B?

PWMEX = 0xFF
PWMDATA - =1

End

PWMEX  - =1

N

Y

Increase PWM duty cycle

Start

PWMEX>=

11111100B?

PWMEX + = 1

End

PWMEX = 0

PWMDATA + =1

 

  Change rate of PWM duty cycle: If PWM in S3F84P4 is 6+6 type, the PWM basic frequency is 6-bit, that 

is,

6

8

125

2

64





8



 when

. The overall cycle is still 12-bit to make the 12-bit 

resolution fully valid, that is, 

12

2

4096

0.512

8





. So Therefore, every change of the duty cycle will 

take effect after 0.512ms. Considering the AD conversion duration is 25us, duty cycle can be updated every 
21 times of AD conversion.