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// Game_Music_Emu 0.6-pre. http://www.slack.net/~ant/
#include "z80_cpu.h"
/* Copyright (C) 2006-2008 Shay Green. This module is free software; you
can redistribute it and/or modify it under the terms of the GNU Lesser
General Public License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version. This
module 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 Lesser General Public License for more
details. You should have received a copy of the GNU Lesser General Public
License along with this module; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
#include "blargg_source.h"
// flags, named with hex value for clarity
int const S80 = 0x80;
int const Z40 = 0x40;
int const F20 = 0x20;
int const H10 = 0x10;
int const F08 = 0x08;
int const V04 = 0x04;
int const P04 = 0x04;
int const N02 = 0x02;
int const C01 = 0x01;
void Z80_init( struct Z80_Cpu* this )
{
this->cpu_state = &this->cpu_state_;
int i;
for ( i = 0x100; --i >= 0; )
{
int p, even = 1;
for ( p = i; p; p >>= 1 )
even ^= p;
int n = (i & (S80 | F20 | F08)) | ((even & 1) * P04);
this->szpc [i] = n;
this->szpc [i + 0x100] = n | C01;
}
this->szpc [0x000] |= Z40;
this->szpc [0x100] |= Z40;
}
static inline void set_page( struct Z80_Cpu* this, int i, void* write, void const* read )
{
int offset = Z80_CPU_OFFSET( i * page_size );
byte * write2 = STATIC_CAST(byte *,write) - offset;
byte const* read2 = STATIC_CAST(byte const*,read ) - offset;
this->cpu_state_.write [i] = write2;
this->cpu_state_.read [i] = read2;
this->cpu_state->write [i] = write2;
this->cpu_state->read [i] = read2;
}
void Z80_reset( struct Z80_Cpu* this, void* unmapped_write, void const* unmapped_read )
{
check( this->cpu_state == &this->cpu_state_ );
this->cpu_state = &this->cpu_state_;
this->cpu_state_.time = 0;
this->cpu_state_.base = 0;
this->end_time_ = 0;
int i;
for ( i = 0; i < page_count + 1; i++ )
set_page( this, i, unmapped_write, unmapped_read );
memset( &this->r, 0, sizeof this->r );
}
void Z80_map_mem( struct Z80_Cpu* this, addr_t start, int size, void* write, void const* read )
{
// address range must begin and end on page boundaries
require( start % page_size == 0 );
require( size % page_size == 0 );
require( start + size <= 0x10000 );
int offset;
for ( offset = 0; offset < size; offset += page_size )
set_page( this, (start + offset) >> page_bits,
STATIC_CAST(char *,write) + offset,
STATIC_CAST(char const*,read ) + offset );
}
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