Page 47 - DEC40053 Ebook_Timer
P. 47

Finding  Values  to  be


             Loaded into the Timer









     Example:




     Assuming XTAL=10MHz and no prescaler with a

     period of 10ms







     1.  Divide the desired value of time delay by 0.4us


       ;;Tocs=1/(Fosc/4)=0.4us ; T=10ms/2=5ms


                       ::Clocks=5ms/0.4us=12500(dec)









     2. Perform (65535-n)+1. where n is the decimal


     value ;; NOC=(65535-12500)+1 = 53036(dec)


                                                      = CF2C(hex)




     3.  Convert  the  result  to  hex,  where  YYXX  is  the


     initial  hex  value  to  be  loaded  into  the  timer's


     register ;; 53036(dec)= CF2C(hex)










     4.  Set TMR0L=XX and TMR0H = YY


         ;;TMR0H=CF(hex) AND TMR0L=2C(hex)

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