RACE/DrZ80_support.cpp
Francisco José García García 82292fc0a8 DRZ80 support
2019-12-28 13:00:07 +01:00

103 lines
2.8 KiB
C++

//---------------------------------------------------------------------------
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version. See also the license.txt file for
// additional informations.
//---------------------------------------------------------------------------
//
// Support functions for interfacing with DrZ80
//
#ifndef __GP32__
#include "StdAfx.h"
#endif
#include "main.h"
#include "memory.h"
//#include "mainemu.h"
#include "DrZ80_support.h"
#define INT_IRQ 0x01
#define NMI_IRQ 0x08
Z80_Regs Z80;
#define z80_int() Z80.regs.Z80_IRQ = INT_IRQ
#define z80_nmi() Z80.regs.Z80IF |= NMI_IRQ
static unsigned int z80_rebaseSP(unsigned short address)
{
Z80.regs.Z80SP_BASE = (unsigned int)&mainram[0x3000];
Z80.regs.Z80SP = Z80.regs.Z80SP_BASE + address;
return Z80.regs.Z80SP_BASE + address;
}
static unsigned int z80_rebasePC(unsigned short address)
{
Z80.regs.Z80PC_BASE = (unsigned int)&mainram[0x3000];
Z80.regs.Z80PC = Z80.regs.Z80PC_BASE + address;
return Z80.regs.Z80PC_BASE + address;
}
static void z80_irq_callback(void)
{
Z80.regs.Z80_IRQ = 0x00;
}
/****************************************************************************
* Reset registers to their initial values
****************************************************************************/
void Z80_Reset(void)
{
memset (&Z80, 0, sizeof(Z80_Regs));
Z80.regs.z80_rebasePC=z80_rebasePC;
Z80.regs.z80_rebaseSP=z80_rebaseSP /* 0 */;
Z80.regs.z80_read8 =z80MemReadB; /* z80_read8 */
Z80.regs.z80_read16 =z80MemReadW;
Z80.regs.z80_write8 =DrZ80ngpMemWriteB;
Z80.regs.z80_write16 =DrZ80ngpMemWriteW;
Z80.regs.z80_in =DrZ80ngpPortReadB;
Z80.regs.z80_out =DrZ80ngpPortWriteB;
Z80.regs.z80_irq_callback=z80_irq_callback;
Z80.regs.Z80BC = 0013;
Z80.regs.Z80DE = 0x00D8;
Z80.regs.Z80HL = 0x014D;
Z80.regs.Z80PC=Z80.regs.z80_rebasePC(0);
Z80.regs.Z80SP=Z80.regs.z80_rebaseSP(0xFFFE);
Z80_Clear_Pending_Interrupts();
}
void Z80_Cause_Interrupt(int type)
{
if (type == Z80_NMI_INT)
{
z80_nmi();
}
else if (type != Z80_IGNORE_INT)
{
z80_int();
}
}
void Z80_Clear_Pending_Interrupts(void)
{
Z80.regs.Z80_IRQ = 0x00;
}
/****************************************************************************
* Execute IPeriod T-states. Return number of T-states really executed
****************************************************************************/
extern "C" int Z80_Execute(int cycles)
{
Z80.regs.cycles = cycles;
DrZ80Run(&Z80.regs, cycles);
return cycles;// (cycles-Z80.regs.cycles);
}