Supermodel/Src/CPU/Z80/Z80.h
Bart Trzynadlowski 46bc52bb12 - Changed save state error messages slightly.
- Wrapped rows that exceed 80 columns in Supermodel.ini.
- Added some member and function comments to a few header files. 
- Changed version string to 0.2a-RC2 in anticipation of sending another release candidate build to testers.
- Added GAME_INPUT_RALLY flag to dirtdvlsa, eca, and ecax.
- Configuration dialog no longer refers to Sega Rally 2 and Dirt Devils; instead, "Miscellaneous Driving Game Buttons"
- More additions to README.txt.
2011-09-22 06:11:47 +00:00

338 lines
9.2 KiB
C++

/**
** Supermodel
** A Sega Model 3 Arcade Emulator.
** Copyright 2011 Bart Trzynadlowski, Nik Henson
**
** This file is part of Supermodel.
**
** Supermodel 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 3 of the License, or (at your option)
** any later version.
**
** Supermodel 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 Supermodel. If not, see <http://www.gnu.org/licenses/>.
**/
/*
* Z80.h
*
* Z80 emulator header file. Based on the Z80 instruction set simulator by
* Frank D. Cringle and taken from YAZE-AG by Andreas Gerlich.
*
* Known inaccuracies:
*
* - Interrupts are accepted immediately after EI instruction. In reality,
* interrupts become enabled after the instruction following EI. This
* could be implemented with a state machine in Run() if needed.
* This feature exists to prevent interrupts from occuring before a RETI
* instruction executes in the interrupt handler. Interrupt callbacks
* should take care to immediately clear the interrupt line, otherwise,
* an improperly timed interrupt may occur right after an EI instruction
* but before the service routine has a chance to return.
* - HALT instruction is not implemented (it just exits).
* - 16-bit words are read as two bytes but these reads may not occur in
* the exact same order as the real device. Needs to be checked.
*/
#ifndef INCLUDED_Z80_H
#define INCLUDED_Z80_H
#include "Types.h"
#include "CPU/Bus.h"
#include "BlockFile.h"
/*
* Special Return Codes for Interrupt Callbacks
*
* When the Z80 takes an interrupt in mode 0, it expects an instruction (up to
* 3 bytes) to be presented on the bus. Typically, an RST instruction is
* supplied, and this is the only supported behavior here. The interrupt
* callback must return one of these values when the Z80 is in mode 0.
*/
#define Z80_INT_RST_00 0xC7 // RST 0x00 (jumps to 0x0000)
#define Z80_INT_RST_08 0xCF // RST 0x08 (jumps to 0x0008)
#define Z80_INT_RST_10 0xD7 // RST 0x10 (...)
#define Z80_INT_RST_18 0xDF // RST 0x18
#define Z80_INT_RST_20 0xE7 // RST 0x20
#define Z80_INT_RST_28 0xEF // RST 0x28
#define Z80_INT_RST_30 0xF7 // RST 0x30
#define Z80_INT_RST_38 0xFF // RST 0x38
#ifdef SUPERMODEL_DEBUGGER
// Extra interrupt types
#define Z80_EX_NMI 0
#define Z80_IM1_IRQ 1
#define Z80_IM2_VECTOR 2
// 8-bit registers
#define Z80_REG8_IFF 0
#define Z80_REG8_IM 1
#define Z80_REG8_I 2
#define Z80_REG8_R 3
#define Z80_REG8_A 4
#define Z80_REG8_F 5
#define Z80_REG8_B 6
#define Z80_REG8_C 7
#define Z80_REG8_D 8
#define Z80_REG8_E 9
#define Z80_REG8_H 10
#define Z80_REG8_L 11
// 16-bit registers
#define Z80_REG16_SP 0
#define Z80_REG16_PC 1
#define Z80_REG16_IR 2
#define Z80_REG16_AF 3
#define Z80_REG16_BC 4
#define Z80_REG16_DE 5
#define Z80_REG16_HL 6
#define Z80_REG16_IX 7
#define Z80_REG16_IY 8
#define Z80_REG16_AF_ 9
#define Z80_REG16_BC_ 10
#define Z80_REG16_DE_ 11
#define Z80_REG16_HL_ 12
class Debugger::CZ80Debug;
#endif // SUPERMODEL_DEBUGGER
/*
* CZ80:
*
* A Z80 CPU.
*/
class CZ80
{
public:
/*
* Run(numCycles):
*
* Runs the Z80 for the specified number of instruction cycles.
*
* Parameters:
* numCycles Number of instruction cycles to execute.
*
* Returns:
* Number of instruction cycles actually executed.
*/
int Run(int numCycles);
/*
* TriggerNMI(void):
*
* Triggers a non-maskable interrupt. This is equivalent to a high-to-low
* transition on the NMI pin (NMI pin is triggered on falling edges). This
* may be called while the Z80 is running. NMIs are always higher priority
* than interrupts and are taken first.
*/
void TriggerNMI(void);
/*
* SetINT(state):
*
* Set or clear the interrupt request. This may be called from memory
* handlers while the Z80 is running and should be used by interrupt
* callbacks to clear interrupts.
*
* Parameters:
* state If TRUE, this is equivalent to /INT being asserted on the
* Z80 (INT line low, which triggers an interrupt). If FALSE,
* this deasserts /INT (INT line high, no interrupt pending).
*/
void SetINT(bool state);
/*
* GetPC(void):
*
* Returns the current PC value.
*
* Returns:
* Current value of PC register.
*/
UINT16 GetPC(void);
#ifdef SUPERMODEL_DEBUGGER
/*
* GetReg8(reg8):
*
* Reads an 8-bit register.
*
* Parameters:
* reg8 Register number (use Z80_REG8_* macros).
*
* Returns:
* Value of given 8-bit register.
*/
UINT8 GetReg8(unsigned reg8);
/*
* SetReg8(reg8, value):
*
* Sets value of given 8-bit register.
*
* Parameters:
* reg8 Register number.
* value Value to write.
*
* Returns:
* True if succeeded, false if invalid register.
*/
bool SetReg8(unsigned reg8, UINT8 value);
/*
* GetReg16(reg16, value):
*
* Reads a 16-bit register.
*
* Parameters:
* reg16 Register number (use Z80_REG16_* macros).
*
* Returns:
* Value of given 16-bit register.
*/
UINT16 GetReg16(unsigned reg16);
/*
* SetReg16(state):
*
* Sets value of given 16-bit register.
*
* Parameters:
* reg16 Register.
* value Value to write.
*
* Returns:
* True if succeeded, false if invalid register.
*/
bool SetReg16(unsigned reg16, UINT16 value);
#endif // SUPERMODEL_DEBUGGER
/*
* Reset(void):
*
* Resets the Z80, clearing all registers and pending interrupt requests.
*/
void Reset(void);
/*
* SaveState(StateFile, name):
*
* Saves the CPU state to the block file.
*
* Parameters:
* StateFile Block file.
* name Name of block to create (e.g. "Main Z80"), to facilitate
* multiple Z80 states in the same file.
*/
void SaveState(CBlockFile *StateFile, const char *name);
/*
* LoadState(StateFile, name):
*
* Loads the CPU state.
*
* Parameters:
* StateFile Block file.
* name Name of block to load.
*/
void LoadState(CBlockFile *StateFile, const char *name);
/*
* Init(BusPtr, INTF):
*
* One-time initialization of the Z80 emulator. Must be called first.
*
* A bus object must be supplied which will be used to handle all memory
* and IO accesses. The Read8, Write8, IORead8, and IOWrite8 members need
* to be defined. Addresses are automatically clamped to 16 bits for memory
* and 8 bits for IO accesses.
*
* An interrupt callback, which is called each time an interrupt occurs,
* should also be supplied. The interrupt callback should explicitly clear
* the INT status (using SetINT(FALSE)) and then return the appropriate
* vector depending on the interrupt mode that is used by the system.
*
* For mode 0, only Z80_INT_RST_* values are acceptable. For mode 1, the
* return value is discarded because the Z80 will always use vector 0x0038.
* In mode 2, an 8-bit value supplying the lower 8-bits of the interrupt
* vector address must be returned. Bit 0 will be ignored in this case (0
* is used).
*
* If a callback is not installed, the interrupt status will automatically
* be cleared and interrupts will not be taken when the Z80 is in a mode
* that requires vector data from the callback. In mode 1, the interrupt
* callback (if one is provided) should explicitly clear the interrupt. The
* value returned will be unused.
*
* Parameters:
* BusPtr Pointer to a bus object.
* INTF Pointer to callback function. The function accepts a
* a pointer to the Z80 object that received the interrupt.
*/
void Init(CBus *BusPtr, int (*INTF)(CZ80 *Z80));
#ifdef SUPERMODEL_DEBUGGER
/*
* AttachDebugger(DebugPtr):
*
* Attaches debugger to CPU.
*/
void AttachDebugger(Debugger::CZ80Debug *DebugPtr);
/*
* DetachDebugger():
*
* Detaches debugger from CPU.
*/
void DetachDebugger();
#endif // SUPERMODEL_DEBUGGER
/*
* CZ80(void):
* ~CZ80(void):
*
* Constructor and destructor.
*/
CZ80(void);
~CZ80(void);
private:
// Registers
struct GPR { // general purpose registers
UINT16 bc;
UINT16 de;
UINT16 hl;
} regs[2]; // two sets: primary (0) and alternate (1)
UINT16 af[2]; // AF (primary and alternate)
UINT16 ir; // interrupt vector (I) and memory refresh (R)
UINT16 ix; // index register X
UINT16 iy; // index register Y
UINT16 sp; // stack pointer
UINT16 pc; // program counter
UINT8 iff; // interrupt flip flops (bit 1: IFF2, 0: IFF1)
UINT8 im; // interrupt mode (0, 1, or 2 only)
int regs_sel; // active register set (primary or alternate)
int af_sel; // active AF
// Memory and IO bus
CBus *Bus;
// Interrupts
bool nmiTrigger;
bool intLine;
int (*INTCallback)(CZ80 *Z80);
#ifdef SUPERMODEL_DEBUGGER
int lastCycles;
Debugger::CZ80Debug *Debug;
#endif // SUPERMODEL_DEBUGGER
};
#endif // INCLUDED_Z80_H