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/* |
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* CPUC64.h - 6510 (C64) emulation (line based) |
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* |
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* Frodo (C) 1994-1997,2002-2004 Christian Bauer |
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* |
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* This program is free software; you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License as published by |
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* the Free Software Foundation; either version 2 of the License, or |
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* (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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*/ |
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|
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#ifndef _CPU_C64_H |
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#define _CPU_C64_H |
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|
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#include "C64.h" |
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|
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|
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// Set this to 1 if the 6502 PC should be represented by a real pointer |
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#ifndef FRODO_SC |
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#ifndef PC_IS_POINTER |
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#define PC_IS_POINTER 1 |
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#endif |
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#endif |
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|
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// Set this to 1 for more precise CPU cycle calculation |
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#ifndef PRECISE_CPU_CYCLES |
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#define PRECISE_CPU_CYCLES 0 |
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#endif |
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|
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// Set this to 1 for instruction-aligned CIA emulation |
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#ifndef PRECISE_CIA_CYCLES |
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#define PRECISE_CIA_CYCLES 0 |
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#endif |
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|
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|
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// Interrupt types |
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enum { |
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INT_VICIRQ, |
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INT_CIAIRQ, |
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INT_NMI |
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// INT_RESET (private) |
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}; |
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|
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|
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class MOS6569; |
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class MOS6581; |
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class MOS6526_1; |
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class MOS6526_2; |
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class REU; |
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class IEC; |
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struct MOS6510State; |
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|
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|
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// 6510 emulation (C64) |
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class MOS6510 { |
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public: |
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MOS6510(C64 *c64, uint8 *Ram, uint8 *Basic, uint8 *Kernal, uint8 *Char, uint8 *Color); |
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|
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#ifdef FRODO_SC |
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void EmulateCycle(void); // Emulate one clock cycle |
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#else |
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int EmulateLine(int cycles_left); // Emulate until cycles_left underflows |
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#endif |
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void Reset(void); |
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void AsyncReset(void); // Reset the CPU asynchronously |
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void AsyncNMI(void); // Raise NMI asynchronously (NMI pulse) |
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void GetState(MOS6510State *s); |
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void SetState(MOS6510State *s); |
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uint8 ExtReadByte(uint16 adr); |
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void ExtWriteByte(uint16 adr, uint8 byte); |
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uint8 REUReadByte(uint16 adr); |
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void REUWriteByte(uint16 adr, uint8 byte); |
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|
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void TriggerVICIRQ(void); |
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void ClearVICIRQ(void); |
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void TriggerCIAIRQ(void); |
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void ClearCIAIRQ(void); |
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void TriggerNMI(void); |
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void ClearNMI(void); |
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|
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int ExtConfig; // Memory configuration for ExtRead/WriteByte (0..7) |
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|
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MOS6569 *TheVIC; // Pointer to VIC |
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MOS6581 *TheSID; // Pointer to SID |
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MOS6526_1 *TheCIA1; // Pointer to CIA 1 |
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MOS6526_2 *TheCIA2; // Pointer to CIA 2 |
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REU *TheREU; // Pointer to REU |
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IEC *TheIEC; // Pointer to drive array |
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|
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#ifdef FRODO_SC |
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bool BALow; // BA line for Frodo SC |
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#endif |
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|
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private: |
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uint8 read_byte(uint16 adr); |
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uint8 read_byte_io(uint16 adr); |
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uint16 read_word(uint16 adr); |
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void write_byte(uint16 adr, uint8 byte); |
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void write_byte_io(uint16 adr, uint8 byte); |
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|
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uint8 read_zp(uint16 adr); |
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uint16 read_zp_word(uint16 adr); |
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void write_zp(uint16 adr, uint8 byte); |
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|
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void new_config(void); |
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void illegal_op(uint8 op, uint16 at); |
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void illegal_jump(uint16 at, uint16 to); |
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|
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void do_adc(uint8 byte); |
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void do_sbc(uint8 byte); |
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|
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uint8 read_emulator_id(uint16 adr); |
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|
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C64 *the_c64; // Pointer to C64 object |
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|
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uint8 *ram; // Pointer to main RAM |
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uint8 *basic_rom, *kernal_rom, *char_rom, *color_ram; // Pointers to ROMs and color RAM |
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|
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union { // Pending interrupts |
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uint8 intr[4]; // Index: See definitions above |
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unsigned long intr_any; |
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} interrupt; |
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bool nmi_state; // State of NMI line |
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|
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uint8 n_flag, z_flag; |
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bool v_flag, d_flag, i_flag, c_flag; |
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uint8 a, x, y, sp; |
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|
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#if PC_IS_POINTER |
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uint8 *pc, *pc_base; |
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#else |
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uint16 pc; |
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#endif |
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|
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#ifdef FRODO_SC |
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uint32 first_irq_cycle, first_nmi_cycle; |
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|
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uint8 state, op; // Current state and opcode |
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uint16 ar, ar2; // Address registers |
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uint8 rdbuf; // Data buffer for RMW instructions |
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uint8 ddr, pr; // Processor port |
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#else |
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int borrowed_cycles; // Borrowed cycles from next line |
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#endif |
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|
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bool basic_in, kernal_in, char_in, io_in; |
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uint8 dfff_byte; |
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}; |
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|
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// 6510 state |
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struct MOS6510State { |
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uint8 a, x, y; |
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uint8 p; // Processor flags |
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uint8 ddr, pr; // Port |
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uint16 pc, sp; |
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uint8 intr[4]; // Interrupt state |
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bool nmi_state; |
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uint8 dfff_byte; |
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bool instruction_complete; |
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}; |
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|
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|
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// Interrupt functions |
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#ifdef FRODO_SC |
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inline void MOS6510::TriggerVICIRQ(void) |
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{ |
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if (!(interrupt.intr[INT_VICIRQ] || interrupt.intr[INT_CIAIRQ])) |
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first_irq_cycle = the_c64->CycleCounter; |
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interrupt.intr[INT_VICIRQ] = true; |
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} |
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|
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inline void MOS6510::TriggerCIAIRQ(void) |
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{ |
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if (!(interrupt.intr[INT_VICIRQ] || interrupt.intr[INT_CIAIRQ])) |
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first_irq_cycle = the_c64->CycleCounter; |
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interrupt.intr[INT_CIAIRQ] = true; |
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} |
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|
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inline void MOS6510::TriggerNMI(void) |
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{ |
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if (!nmi_state) { |
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nmi_state = true; |
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interrupt.intr[INT_NMI] = true; |
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first_nmi_cycle = the_c64->CycleCounter; |
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} |
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} |
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#else |
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inline void MOS6510::TriggerVICIRQ(void) |
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{ |
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interrupt.intr[INT_VICIRQ] = true; |
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} |
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|
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inline void MOS6510::TriggerCIAIRQ(void) |
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{ |
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interrupt.intr[INT_CIAIRQ] = true; |
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} |
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|
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inline void MOS6510::TriggerNMI(void) |
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{ |
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if (!nmi_state) { |
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nmi_state = true; |
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interrupt.intr[INT_NMI] = true; |
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} |
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} |
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#endif |
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inline void MOS6510::ClearVICIRQ(void) |
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{ |
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interrupt.intr[INT_VICIRQ] = false; |
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} |
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|
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inline void MOS6510::ClearCIAIRQ(void) |
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{ |
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interrupt.intr[INT_CIAIRQ] = false; |
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} |
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|
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inline void MOS6510::ClearNMI(void) |
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{ |
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nmi_state = false; |
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} |
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|
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#endif |
