mirror of
https://github.com/hsoft/collapseos.git
synced 2024-11-17 10:38:05 +11:00
164 lines
4.4 KiB
C
164 lines
4.4 KiB
C
// This unit has been copied from libz80 into Collapse OS and was slighly changed
|
|
/* =============================================================================
|
|
* libz80 - Z80 emulation library
|
|
* =============================================================================
|
|
*
|
|
* (C) Gabriel Gambetta (gabriel.gambetta@gmail.com) 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);
|