// This unit has been copied from libz80 into Collapse OS and was slighly changed
/* =============================================================================
* libz80 - Z80 emulation library
* =============================================================================
*
* (C) Gabriel Gambetta (
[email protected]) 2000 - 2012
*
* Version 2.1.0
*
* -----------------------------------------------------------------------------
*
* 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.
*/
#pragma once
#include <stdio.h>
typedef unsigned short ushort;
typedef unsigned char byte;
/** Function type to emulate data read. */
typedef byte (*Z80DataIn) (int param, ushort address);
/** Function type to emulate data write. */
typedef void (*Z80DataOut) (int param, ushort address, byte data);
/**
* A Z80 register set.
* An union is used since we want independent access to the high and low bytes of the 16-bit registers.
*/
typedef union
{
/** Word registers. */
struct
{
ushort AF, BC, DE, HL, IX, IY, SP;
} wr;
/** Byte registers. Note that SP can't be accessed partially. */
struct
{
byte F, A, C, B, E, D, L, H, IXl, IXh, IYl, IYh;
} br;
} Z80Regs;
/** The Z80 flags */
typedef enum
{
F_C = 1, /**< Carry */
F_N = 2, /**< Sub / Add */
F_PV = 4, /**< Parity / Overflow */
F_3 = 8, /**< Reserved */
F_H = 16, /**< Half carry */
F_5 = 32, /**< Reserved */
F_Z = 64, /**< Zero */
F_S = 128 /**< Sign */
} Z80Flags;
/** A Z80 execution context. */
typedef struct
{
Z80Regs R1; /**< Main register set (R) */
Z80Regs R2; /**< Alternate register set (R') */
ushort PC; /**< Program counter */
byte R; /**< Refresh */
byte I;
byte IFF1; /**< Interrupt Flipflop 1 */
byte IFF2; /**< Interrupt Flipflop 2 */
byte IM; /**< Instruction mode */
Z80DataIn memRead;
Z80DataOut memWrite;
int memParam;
Z80DataIn ioRead;
Z80DataOut ioWrite;
int ioParam;
byte halted;
unsigned tstates;
/* Below are implementation details which may change without
* warning; they should not be relied upon by any user of this
* library.
*/
/* If true, an NMI has been requested. */
byte nmi_req;
/* If true, a maskable interrupt has been requested. */
byte int_req;
/* If true, defer checking maskable interrupts for one
* instruction. This is used to keep an interrupt from happening
* immediately after an IE instruction. */
byte defer_int;
/* When a maskable interrupt has been requested, the interrupt
* vector. For interrupt mode 1, it's the opcode to execute. For
* interrupt mode 2, it's the LSB of the interrupt vector address.
* Not used for interrupt mode 0.
*/
byte int_vector;
/* If true, then execute the opcode in int_vector. */
byte exec_int_vector;
} Z80Context;
/** Execute the next instruction. */
void Z80Execute (Z80Context* ctx);
/** Execute enough instructions to use at least tstates cycles.
* Returns the number of tstates actually executed. Note: Resets
* ctx->tstates.*/
unsigned Z80ExecuteTStates(Z80Context* ctx, unsigned tstates);
/** Decode the next instruction to be executed.
* dump and decode can be NULL if such information is not needed
*
* @param dump A buffer which receives the hex dump
* @param decode A buffer which receives the decoded instruction
*/
void Z80Debug (Z80Context* ctx, char* dump, char* decode);
/** Resets the processor. */
void Z80RESET (Z80Context* ctx);
/** Generates a hardware interrupt.
* Some interrupt modes read a value from the data bus; this value must be provided in this function call, even
* if the processor ignores that value in the current interrupt mode.
*
* @param value The value to read from the data bus
*/
void Z80INT (Z80Context* ctx, byte value);
/** Generates a non-maskable interrupt. */
void Z80NMI (Z80Context* ctx);
