TimerInterrupts.cpp

   1 #include "TimerInterrupts.h"
   2 #include "Registers.h"
   3 #include "Bus.h"
   4 #include "ImplementationException.h"
   5
   6 namespace avr {
   7
   8         bool TimerInterrupts::attachReg(const char *name, IORegister *reg) {
   9                 if( strcmp(name, "timsk") == 0 )
  10                         timsk = reg;
  11                 else if( strcmp(name, "tifr") == 0 )
  12                         tifr = reg;
  13                 else
  14                         return false;
  15
  16                 reg->registerHW(this);
  17                 return true;
  18         }
  19
  20         void TimerInterrupts::checkForNewSetIrq(unsigned char tiac) {
  21                 tiac &= mask;
  22                 if( tiac & (1<<0) ) { bus.raiseInterrupt( bit0Vec ); }
  23                 if( tiac & (1<<1) ) { bus.raiseInterrupt( bit1Vec ); }
  24                 if( tiac & (1<<2) ) { bus.raiseInterrupt( bit2Vec ); }
  25                 if( tiac & (1<<3) ) { bus.raiseInterrupt( bit3Vec ); }
  26                 if( tiac & (1<<4) ) { bus.raiseInterrupt( bit4Vec ); }
  27                 if( tiac & (1<<5) ) { bus.raiseInterrupt( bit5Vec ); }
  28                 if( tiac & (1<<6) ) { bus.raiseInterrupt( bit6Vec ); }
  29                 if( tiac & (1<<7) ) { bus.raiseInterrupt( bit7Vec ); }
  30
  31         /*
  32          * TODO: Once an irq has been raised, the flag should be cleared,
  33          *   _BUT_ should it be done here? Might be a problem if there are
  34          *   many interrupts pending and then the user wants to clear one.
  35          */
  36                 tifrOld = tifr->get() & ~tiac;
  37                 tifr->set( tifrOld );
  38         }
  39
  40         void TimerInterrupts::checkForNewClearIrq(unsigned char tiac) {
  41                 tiac &= mask;
  42                 if( tiac & (1<<0) ) { bus.clearInterrupt( bit0Vec ); }
  43                 if( tiac & (1<<1) ) { bus.clearInterrupt( bit1Vec ); }
  44                 if( tiac & (1<<2) ) { bus.clearInterrupt( bit2Vec ); }
  45                 if( tiac & (1<<3) ) { bus.clearInterrupt( bit3Vec ); }
  46                 if( tiac & (1<<4) ) { bus.clearInterrupt( bit4Vec ); }
  47                 if( tiac & (1<<5) ) { bus.clearInterrupt( bit5Vec ); }
  48                 if( tiac & (1<<6) ) { bus.clearInterrupt( bit6Vec ); }
  49                 if( tiac & (1<<7) ) { bus.clearInterrupt( bit7Vec ); }
  50         }
  51
  52         void TimerInterrupts::regChanged( IORegister *reg ) {
  53                 unsigned char tiacOld = timskOld & tifrOld;
  54
  55                 if( reg == timsk ) {
  56                     timskOld = *timsk;
  57                 } else if( reg == tifr ) {
  58                     tifrOld = *tifr;
  59                 }
  60
  61                 unsigned char tiacNew= timskOld & tifrOld;
  62
  63             unsigned char changed = tiacNew ^ tiacOld;
  64             unsigned char setnew = changed & tiacNew;
  65             unsigned char clearnew = changed & (~tiacNew);
  66
  67                 checkForNewSetIrq(setnew);
  68                 checkForNewClearIrq(clearnew);
  69         }
  70
  71 }