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- // 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);
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