36 PWM

V0.0.1

36.1 Histroy

• 2014-10-31, rayoslee, release V0.0.1

36.2 FAQ

1. How to config kernel?
   • make menuconfig

   Device Drivers  ---> 
   Graphics support  ---> 
   <*> Support for frame buffer devices  --->  
   [*]     H/W PWM for backlight control 
                  Select PWM init setting (PWM init by driver)  --->     
        [ ]       Reverse PWM value (NEW)

2. How to generate 32.768Khz from PWM0(GPD0) in S605-32 demo kit?
   • modify w55fa9s_fb.c to make it duty ratio 50%

   +++ #define PWM_OUTPUT_FREQUENCY 32768  
   +++ #define PWM_DEFAULT_OUTPUT_FREQUENCY (32768*2)
   --- #define PWM_OUTPUT_FREQUENCY 500  
   --- #define PWM_DEFAULT_OUTPUT_FREQUENCY 500

   • modify duty ratio
     duty ratio = REG_CNR/REG_CMR (REG_CMR = 1:REG_CNR)