casova konstanta

[Marek Pavlu]

Nepouzivejte 4,000MHz, ale 4,096MHz krystal. 

Delicku k TMR0 vypnete, tim ziskate preruseni kazdych: 


4,096 * 10^6 / 4 / 256  = 4000 

Preruseni kazdych 0.25 ms, coz uz staci napocitat do ctyr a mate presne 1ms.

Nicmene kondiky u krystalu Vam lehce ovlivni vysledny kmitocet tez... 


M. Pavlu 
                


>>  -----Original Message----- 
>>  From: hw-list-bounces@list.hw.cz [mailto:hw-list-bounces@list.hw.cz] 
>>  On Behalf Of Libor 
>>  Sent: Saturday, June 16, 2007 8:03 PM 
>>  To: HW-news 
>>  Subject: casova konstanta 
>>  
>>  Zdravim 
>>  Mel bych dotaz jestli by mi nekdo nezkontroloval tento kod pro 
>>  microchoip 16f627 
>>  
>>  Clock je 4MHZ crystal a potreboval bych aby promenna timeticks 
>>  ukazovala 
>>  co nejpresneji milisekundy cili timeticks = 1000   => 1 sekunda 
>>  
>>  void interrupt() { 
>>    timeticks++; 
>>    TMR0   = 101; 
>>    INTCON = 0x20;           // Set T0IE, clear T0IF 
>>  
>>  
>>  } 
>>  
>>  
>>  main 
>>    OPTION_REG = 0x01; 
>>    TMR0  = 101; 
>>    INTCON = 0xA0;           // Enable TMRO interrupt 
>>  
>>  Mockrat diky 
>>  
>>  LK 
>>  _______________________________________________ 
>>  HW-list mailing list  -  sponsored by www.HW.cz 
>>  Hw-list@list.hw.cz 
>>  http://list.hw.cz/mailman/listinfo/hw-list 



  _____  

avast! Antivirus <http://www.avast.com> : Odchozi zprava cista. 


Virova databaze (VPS): 000749-2, 16.06.2007
Testovano: 16.6.2007 20:56:53
avast! - copyright (c) 1988-2007 ALWIL Software.