Stack.cpp

   1 #include "Stack.h"
   2 #include "Registers.h"
   3
   4 namespace avr {
   5
   6         Stack::Stack(Bus & bus, MMU & mmu, word mask)
   7                 : Hardware(bus), mmu(mmu), mask(mask), sp(0) {
   8         }
   9
  10         void Stack::push(unsigned char val) {
  11                 mmu.writeByte(sp, val);
  12                 sp--;
  13                 setSP( sp );
  14         }
  15
  16         unsigned char Stack::pop() {
  17                 sp++;
  18                 setSP( sp );
  19
  20                 return mmu.readByte(sp);
  21         }
  22
  23         void Stack::setSP(word sp) {
  24                 sp &= mask;
  25                 spl->set( getSPL() );
  26                 sph->set( getSPH() );
  27         }
  28
  29         bool Stack::attachReg(const char *name, IORegister *reg) {
  30                 if( strcmp(name, "sph") == 0 )
  31                         sph = reg;
  32                 else if( strcmp(name, "spl") == 0 )
  33                         spl = reg;
  34                 else
  35                         return false;
  36
  37                 reg->registerHW(this);
  38                 return true;
  39         }
  40
  41         void Stack::regChanged(IORegister *reg) {
  42                 if( reg == sph )
  43                         setSPH( (unsigned char)*sph );
  44                 else if( reg == spl )
  45                         setSPL( (unsigned char)*spl );
  46         }
  47
  48         void Stack::step() {
  49
  50         }
  51
  52 }