src/Stack.h

   1 #ifndef AVR_STACK_H
   2 #define AVR_STACK_H
   3
   4 #include "MMU.h"
   5 #include "Hardware.h"
   6
   7 namespace avr {
   8
   9         /**
  10          * @author Tom Haber
  11          * @date Apr 23, 2008
  12          * @brief Represents the stack within the chip.
  13          *
  14          * A software stack implementation. Provides methods
  15          * for pushing and popping.
  16          */
  17         class Stack : public Hardware {
  18                 public:
  19                         Stack(Bus & bus, MMU & mmu, word mask);
  20
  21                 public:
  22                         word getSP() const;
  23                         unsigned char getSPH() const;
  24                         unsigned char getSPL() const;
  25
  26                         void setSP(word sp);
  27
  28                 public:
  29                         void push(unsigned char val);
  30                         unsigned char pop();
  31
  32                 public:
  33                         bool attachReg(const char *name, IORegister *reg);
  34                         bool finishBuild();
  35                         void regChanged(IORegister *reg);
  36
  37                 private:
  38                         void setSPH(unsigned char sph);
  39                         void setSPL(unsigned char spl);
  40
  41                 private:
  42                         MMU & mmu;
  43                         word mask;
  44                         word sp;
  45
  46                 private:
  47                         Register *sph;
  48                         Register *spl;
  49         };
  50
  51         inline unsigned char Stack::getSPH() const {
  52                 return (sp>>8) & 0xff;
  53         }
  54
  55         inline unsigned char Stack::getSPL() const {
  56                 return (sp & 0xff);
  57         }
  58
  59         inline word Stack::getSP() const {
  60                 return sp;
  61         }
  62
  63         inline void Stack::setSPH(unsigned char sph) {
  64                 sp = sp & 0x00ff;
  65                 sp |= (sph<<8);
  66             sp &= mask;
  67         }
  68
  69         inline void Stack::setSPL(unsigned char spl) {
  70                 sp = sp & 0xff00;
  71                 sp |= spl;
  72             sp &= mask;
  73         }
  74
  75 }
  76
  77 #endif /*AVR_STACK_H*/