frodo-wii/Src/CPUC64.h

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2009-01-13 19:46:42 +01:00
/*
* CPUC64.h - 6510 (C64) emulation (line based)
*
* Frodo (C) 1994-1997,2002-2009 Christian Bauer
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _CPU_C64_H
#define _CPU_C64_H
#include "C64.h"
// Set this to 1 if the 6502 PC should be represented by a real pointer
#ifndef FRODO_SC
#ifndef PC_IS_POINTER
#define PC_IS_POINTER 1
#endif
#endif
// Set this to 1 for more precise CPU cycle calculation
#ifndef PRECISE_CPU_CYCLES
#define PRECISE_CPU_CYCLES 0
#endif
// Set this to 1 for instruction-aligned CIA emulation
#ifndef PRECISE_CIA_CYCLES
#define PRECISE_CIA_CYCLES 0
#endif
// Interrupt types
enum {
INT_VICIRQ,
INT_CIAIRQ,
INT_NMI
// INT_RESET (private)
};
class MOS6569;
class MOS6581;
class MOS6526_1;
class MOS6526_2;
class REU;
class IEC;
struct MOS6510State;
// 6510 emulation (C64)
class MOS6510 {
public:
MOS6510(C64 *c64, uint8 *Ram, uint8 *Basic, uint8 *Kernal, uint8 *Char, uint8 *Color);
#ifdef FRODO_SC
void EmulateCycle(void); // Emulate one clock cycle
#else
int EmulateLine(int cycles_left); // Emulate until cycles_left underflows
#endif
void Reset(void);
void AsyncReset(void); // Reset the CPU asynchronously
void AsyncNMI(void); // Raise NMI asynchronously (NMI pulse)
void GetState(MOS6510State *s);
void SetState(MOS6510State *s);
uint8 ExtReadByte(uint16 adr);
void ExtWriteByte(uint16 adr, uint8 byte);
uint8 REUReadByte(uint16 adr);
void REUWriteByte(uint16 adr, uint8 byte);
void TriggerVICIRQ(void);
void ClearVICIRQ(void);
void TriggerCIAIRQ(void);
void ClearCIAIRQ(void);
void TriggerNMI(void);
void ClearNMI(void);
int ExtConfig; // Memory configuration for ExtRead/WriteByte (0..7)
MOS6569 *TheVIC; // Pointer to VIC
MOS6581 *TheSID; // Pointer to SID
MOS6526_1 *TheCIA1; // Pointer to CIA 1
MOS6526_2 *TheCIA2; // Pointer to CIA 2
REU *TheREU; // Pointer to REU
IEC *TheIEC; // Pointer to drive array
#ifdef FRODO_SC
bool BALow; // BA line for Frodo SC
#endif
private:
uint8 read_byte(uint16 adr);
uint8 read_byte_io(uint16 adr);
uint16 read_word(uint16 adr);
void write_byte(uint16 adr, uint8 byte);
void write_byte_io(uint16 adr, uint8 byte);
uint8 read_zp(uint16 adr);
uint16 read_zp_word(uint16 adr);
void write_zp(uint16 adr, uint8 byte);
void new_config(void);
void illegal_op(uint8 op, uint16 at);
void illegal_jump(uint16 at, uint16 to);
void do_adc(uint8 byte);
void do_sbc(uint8 byte);
uint8 read_emulator_id(uint16 adr);
C64 *the_c64; // Pointer to C64 object
uint8 *ram; // Pointer to main RAM
uint8 *basic_rom, *kernal_rom, *char_rom, *color_ram; // Pointers to ROMs and color RAM
union { // Pending interrupts
uint8 intr[4]; // Index: See definitions above
unsigned long intr_any;
} interrupt;
bool nmi_state; // State of NMI line
uint8 n_flag, z_flag;
bool v_flag, d_flag, i_flag, c_flag;
uint8 a, x, y, sp;
#if PC_IS_POINTER
uint8 *pc, *pc_base;
#else
uint16 pc;
#endif
#ifdef FRODO_SC
uint32 first_irq_cycle, first_nmi_cycle;
uint8 state, op; // Current state and opcode
uint16 ar, ar2; // Address registers
uint8 rdbuf; // Data buffer for RMW instructions
uint8 ddr, pr, pr_out; // Processor port
#else
int borrowed_cycles; // Borrowed cycles from next line
#endif
bool basic_in, kernal_in, char_in, io_in;
uint8 dfff_byte;
};
// 6510 state
struct MOS6510State {
uint8 a, x, y;
uint8 p; // Processor flags
uint8 ddr, pr; // Port
uint16 pc, sp;
uint8 intr[4]; // Interrupt state
bool nmi_state;
uint8 dfff_byte;
bool instruction_complete;
};
// Interrupt functions
#ifdef FRODO_SC
inline void MOS6510::TriggerVICIRQ(void)
{
if (!(interrupt.intr[INT_VICIRQ] || interrupt.intr[INT_CIAIRQ]))
first_irq_cycle = the_c64->CycleCounter;
interrupt.intr[INT_VICIRQ] = true;
}
inline void MOS6510::TriggerCIAIRQ(void)
{
if (!(interrupt.intr[INT_VICIRQ] || interrupt.intr[INT_CIAIRQ]))
first_irq_cycle = the_c64->CycleCounter;
interrupt.intr[INT_CIAIRQ] = true;
}
inline void MOS6510::TriggerNMI(void)
{
if (!nmi_state) {
nmi_state = true;
interrupt.intr[INT_NMI] = true;
first_nmi_cycle = the_c64->CycleCounter;
}
}
#else
inline void MOS6510::TriggerVICIRQ(void)
{
interrupt.intr[INT_VICIRQ] = true;
}
inline void MOS6510::TriggerCIAIRQ(void)
{
interrupt.intr[INT_CIAIRQ] = true;
}
inline void MOS6510::TriggerNMI(void)
{
if (!nmi_state) {
nmi_state = true;
interrupt.intr[INT_NMI] = true;
}
}
#endif
inline void MOS6510::ClearVICIRQ(void)
{
interrupt.intr[INT_VICIRQ] = false;
}
inline void MOS6510::ClearCIAIRQ(void)
{
interrupt.intr[INT_CIAIRQ] = false;
}
inline void MOS6510::ClearNMI(void)
{
nmi_state = false;
}
#endif