575 lines
17 KiB
C++
575 lines
17 KiB
C++
// Core SPC emulation: CPU, timers, SMP registers, memory
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// snes_spc $vers. http://www.slack.net/~ant/
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#include "Snes_Spc.h"
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/* Copyright (C) 2004-2007 Shay Green. This module is free software; you
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can redistribute it and/or modify it under the terms of the GNU Lesser
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General Public License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version. This
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module is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
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details. You should have received a copy of the GNU Lesser General Public
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License along with this module; if not, write to the Free Software Foundation,
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Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
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#include "blargg_source.h"
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#define RAM (m.ram.ram)
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#define REGS (m.smp_regs [0])
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#define REGS_IN (m.smp_regs [1])
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// (n ? n : 256)
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#define IF_0_THEN_256( n ) ((uint8_t) ((n) - 1) + 1)
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// Note: SPC_MORE_ACCURACY exists mainly so I can run my validation tests, which
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// do crazy echo buffer accesses.
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#ifndef SPC_MORE_ACCURACY
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#define SPC_MORE_ACCURACY 0
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#endif
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//// Timers
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#define TIMER_DIV( t, n ) ((n) / t->prescaler)
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#define TIMER_MUL( t, n ) ((n) * t->prescaler)
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Snes_Spc::Timer* Snes_Spc::run_timer_( Timer* t, rel_time_t time )
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{
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int elapsed = TIMER_DIV( t, time - t->next_time ) + 1;
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t->next_time += TIMER_MUL( t, elapsed );
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if ( t->enabled )
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{
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int remain = IF_0_THEN_256( t->period - t->divider );
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int divider = t->divider + elapsed;
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int over = elapsed - remain;
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if ( over >= 0 )
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{
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int n = over / t->period;
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t->counter = (t->counter + 1 + n) & 0x0F;
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divider = over - n * t->period;
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}
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t->divider = (uint8_t) divider;
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}
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return t;
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}
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inline Snes_Spc::Timer* Snes_Spc::run_timer( Timer* t, rel_time_t time )
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{
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if ( time >= t->next_time )
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t = run_timer_( t, time );
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return t;
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}
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//// ROM
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void Snes_Spc::enable_rom( int enable )
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{
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if ( m.rom_enabled != enable )
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{
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m.rom_enabled = enable;
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if ( enable )
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memcpy( m.hi_ram, &RAM [rom_addr], sizeof m.hi_ram );
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memcpy( &RAM [rom_addr], (enable ? m.rom : m.hi_ram), rom_size );
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// TODO: ROM can still get overwritten when DSP writes to echo buffer
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}
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}
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//// DSP
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#if SPC_LESS_ACCURATE
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int const max_reg_time = 29;
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/* Fast DSP only runs every 32nd clock. By adjusting the end time based
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on which register is being accessed, in most cases the register access
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is emulated at the precise time. */
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signed char const Snes_Spc::reg_times_ [256] =
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{
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-1, 0,-11,-10,-15,-11, -2, -2, 4, 3, 14, 14, 26, 26, 14, 22,
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2, 3, 0, 1,-12, 0, 1, 1, 7, 6, 14, 14, 27, 14, 14, 23,
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5, 6, 3, 4, -1, 3, 4, 4, 10, 9, 14, 14, 26, -5, 14, 23,
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8, 9, 6, 7, 2, 6, 7, 7, 13, 12, 14, 14, 27, -4, 14, 24,
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11, 12, 9, 10, 5, 9, 10, 10, 16, 15, 14, 14, -2, -4, 14, 24,
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14, 15, 12, 13, 8, 12, 13, 13, 19, 18, 14, 14, -2,-36, 14, 24,
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17, 18, 15, 16, 11, 15, 16, 16, 22, 21, 14, 14, 28, -3, 14, 25,
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20, 21, 18, 19, 14, 18, 19, 19, 25, 24, 14, 14, 14, 29, 14, 25,
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29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
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29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
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29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
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29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
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29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
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29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
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29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
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29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
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};
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#define RUN_DSP( time, offset ) \
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int count = (time) - (offset) - m.dsp_time;\
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if ( count >= 0 )\
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{\
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int clock_count = (count & ~(clocks_per_sample - 1)) + clocks_per_sample;\
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m.dsp_time += clock_count;\
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dsp.run( clock_count );\
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}
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#else
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#define RUN_DSP( time, offset ) \
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{\
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int count = (time) - m.dsp_time;\
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if ( !SPC_MORE_ACCURACY || count )\
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{\
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assert( count > 0 );\
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m.dsp_time = (time);\
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dsp.run( count );\
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}\
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}
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#endif
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int Snes_Spc::dsp_read( rel_time_t time )
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{
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RUN_DSP( time, reg_times [REGS [r_dspaddr] & 0x7F] );
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int result = dsp.read( REGS [r_dspaddr] & 0x7F );
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#ifdef SPC_DSP_READ_HOOK
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SPC_DSP_READ_HOOK( spc_time + time, (REGS [r_dspaddr] & 0x7F), result );
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#endif
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return result;
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}
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inline void Snes_Spc::dsp_write( int data, rel_time_t time )
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{
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RUN_DSP( time, reg_times [REGS [r_dspaddr]] )
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#if SPC_LESS_ACCURATE
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else if ( m.dsp_time == skipping_time )
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{
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int r = REGS [r_dspaddr];
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if ( r == Spc_Dsp::r_kon )
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m.skipped_kon |= data & ~dsp.read( Spc_Dsp::r_koff );
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if ( r == Spc_Dsp::r_koff )
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{
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m.skipped_koff |= data;
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m.skipped_kon &= ~data;
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}
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}
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#endif
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#ifdef SPC_DSP_WRITE_HOOK
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SPC_DSP_WRITE_HOOK( m.spc_time + time, REGS [r_dspaddr], (uint8_t) data );
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#endif
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if ( REGS [r_dspaddr] <= 0x7F )
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{
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if ( REGS [r_dspaddr] != Spc_Dsp::r_flg )
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dsp.write( REGS [r_dspaddr], data );
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else
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{
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int prev = dsp.read( Spc_Dsp::r_flg );
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dsp.write( Spc_Dsp::r_flg, data );
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if ( ( data & 0x20 ) == ( ( data ^ prev ) & 0x20 ) ) clear_echo();
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}
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}
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else if ( !SPC_MORE_ACCURACY )
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dprintf( "SPC wrote to DSP register > $7F\n" );
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}
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//// Memory access extras
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#if SPC_MORE_ACCURACY
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#define MEM_ACCESS( time, addr ) \
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{\
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if ( time >= m.dsp_time )\
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{\
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RUN_DSP( time, max_reg_time );\
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}\
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}
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#elif !defined (NDEBUG)
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// Debug-only check for read/write within echo buffer, since this might result in
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// inaccurate emulation due to the DSP not being caught up to the present.
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bool Snes_Spc::check_echo_access( int addr )
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{
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if ( !(dsp.read( Spc_Dsp::r_flg ) & 0x20) )
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{
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int start = 0x100 * dsp.read( Spc_Dsp::r_esa );
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int size = 0x800 * (dsp.read( Spc_Dsp::r_edl ) & 0x0F);
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int end = start + (size ? size : 4);
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if ( start <= addr && addr < end )
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{
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if ( !m.echo_accessed )
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{
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m.echo_accessed = 1;
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return true;
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}
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}
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}
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return false;
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}
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#define MEM_ACCESS( time, addr ) check( !check_echo_access( (uint16_t) addr ) );
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#else
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#define MEM_ACCESS( time, addr )
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#endif
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//// CPU write
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#if SPC_MORE_ACCURACY
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static unsigned char const glitch_probs [3] [256] =
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{
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0xC3,0x92,0x5B,0x1C,0xD1,0x92,0x5B,0x1C,0xDB,0x9C,0x72,0x18,0xCD,0x5C,0x38,0x0B,
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0xE1,0x9C,0x74,0x17,0xCF,0x75,0x45,0x0C,0xCF,0x6E,0x4A,0x0D,0xA3,0x3A,0x1D,0x08,
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0xDB,0xA0,0x82,0x19,0xD9,0x73,0x3C,0x0E,0xCB,0x76,0x52,0x0B,0xA5,0x46,0x1D,0x09,
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0xDA,0x74,0x55,0x0F,0xA2,0x3F,0x21,0x05,0x9A,0x40,0x20,0x07,0x63,0x1E,0x10,0x01,
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0xDF,0xA9,0x85,0x1D,0xD3,0x84,0x4B,0x0E,0xCF,0x6F,0x49,0x0F,0xB3,0x48,0x1E,0x05,
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0xD8,0x77,0x52,0x12,0xB7,0x49,0x23,0x06,0xAA,0x45,0x28,0x07,0x7D,0x28,0x0F,0x07,
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0xCC,0x7B,0x4A,0x0E,0xB2,0x4F,0x24,0x07,0xAD,0x43,0x2C,0x06,0x86,0x29,0x11,0x07,
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0xAE,0x48,0x1F,0x0A,0x76,0x21,0x19,0x05,0x76,0x21,0x14,0x05,0x44,0x11,0x0B,0x01,
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0xE7,0xAD,0x96,0x23,0xDC,0x86,0x59,0x0E,0xDC,0x7C,0x5F,0x15,0xBB,0x53,0x2E,0x09,
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0xD6,0x7C,0x4A,0x16,0xBB,0x4A,0x25,0x08,0xB3,0x4F,0x28,0x0B,0x8E,0x23,0x15,0x08,
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0xCF,0x7F,0x57,0x11,0xB5,0x4A,0x23,0x0A,0xAA,0x42,0x28,0x05,0x7D,0x22,0x12,0x03,
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0xA6,0x49,0x28,0x09,0x82,0x2B,0x0D,0x04,0x7A,0x20,0x0F,0x04,0x3D,0x0F,0x09,0x03,
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0xD1,0x7C,0x4C,0x0F,0xAF,0x4E,0x21,0x09,0xA8,0x46,0x2A,0x07,0x85,0x1F,0x0E,0x07,
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0xA6,0x3F,0x26,0x07,0x7C,0x24,0x14,0x07,0x78,0x22,0x16,0x04,0x46,0x12,0x0A,0x02,
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0xA6,0x41,0x2C,0x0A,0x7E,0x28,0x11,0x05,0x73,0x1B,0x14,0x05,0x3D,0x11,0x0A,0x02,
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0x70,0x22,0x17,0x05,0x48,0x13,0x08,0x03,0x3C,0x07,0x0D,0x07,0x26,0x07,0x06,0x01,
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0xE0,0x9F,0xDA,0x7C,0x4F,0x18,0x28,0x0D,0xE9,0x9F,0xDA,0x7C,0x4F,0x18,0x1F,0x07,
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0xE6,0x97,0xD8,0x72,0x64,0x13,0x26,0x09,0xDC,0x67,0xA9,0x38,0x21,0x07,0x15,0x06,
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0xE9,0x91,0xD2,0x6B,0x63,0x14,0x2B,0x0E,0xD6,0x61,0xB7,0x41,0x2B,0x0E,0x10,0x09,
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0xCF,0x59,0xB0,0x2F,0x35,0x08,0x0F,0x07,0xB6,0x30,0x7A,0x21,0x17,0x07,0x09,0x03,
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0xE7,0xA3,0xE5,0x6B,0x65,0x1F,0x34,0x09,0xD8,0x6B,0xBE,0x45,0x27,0x07,0x10,0x07,
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0xDA,0x54,0xB1,0x39,0x2E,0x0E,0x17,0x08,0xA9,0x3C,0x86,0x22,0x16,0x06,0x07,0x03,
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0xD4,0x51,0xBC,0x3D,0x38,0x0A,0x13,0x06,0xB2,0x37,0x79,0x1C,0x17,0x05,0x0E,0x06,
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0xA7,0x31,0x74,0x1C,0x11,0x06,0x0C,0x02,0x6D,0x1A,0x38,0x10,0x0B,0x05,0x06,0x03,
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0xEB,0x9A,0xE1,0x7A,0x6F,0x13,0x34,0x0E,0xE6,0x75,0xC5,0x45,0x3E,0x0B,0x1A,0x05,
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0xD8,0x63,0xC1,0x40,0x3C,0x1B,0x19,0x06,0xB3,0x42,0x83,0x29,0x18,0x0A,0x08,0x04,
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0xD4,0x58,0xBA,0x43,0x3F,0x0A,0x1F,0x09,0xB1,0x33,0x8A,0x1F,0x1F,0x06,0x0D,0x05,
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0xAF,0x3C,0x7A,0x1F,0x16,0x08,0x0A,0x01,0x72,0x1B,0x52,0x0D,0x0B,0x09,0x06,0x01,
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0xCF,0x63,0xB7,0x47,0x40,0x10,0x14,0x06,0xC0,0x41,0x96,0x20,0x1C,0x09,0x10,0x05,
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0xA6,0x35,0x82,0x1A,0x20,0x0C,0x0E,0x04,0x80,0x1F,0x53,0x0F,0x0B,0x02,0x06,0x01,
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0xA6,0x31,0x81,0x1B,0x1D,0x01,0x08,0x08,0x7B,0x20,0x4D,0x19,0x0E,0x05,0x07,0x03,
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0x6B,0x17,0x49,0x07,0x0E,0x03,0x0A,0x05,0x37,0x0B,0x1F,0x06,0x04,0x02,0x07,0x01,
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0xF0,0xD6,0xED,0xAD,0xEC,0xB1,0xEB,0x79,0xAC,0x22,0x47,0x1E,0x6E,0x1B,0x32,0x0A,
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0xF0,0xD6,0xEA,0xA4,0xED,0xC4,0xDE,0x82,0x98,0x1F,0x50,0x13,0x52,0x15,0x2A,0x0A,
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0xF1,0xD1,0xEB,0xA2,0xEB,0xB7,0xD8,0x69,0xA2,0x1F,0x5B,0x18,0x55,0x18,0x2C,0x0A,
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0xED,0xB5,0xDE,0x7E,0xE6,0x85,0xD3,0x59,0x59,0x0F,0x2C,0x09,0x24,0x07,0x15,0x09,
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0xF1,0xD6,0xEA,0xA0,0xEC,0xBB,0xDA,0x77,0xA9,0x23,0x58,0x14,0x5D,0x12,0x2F,0x09,
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0xF1,0xC1,0xE3,0x86,0xE4,0x87,0xD2,0x4E,0x68,0x15,0x26,0x0B,0x27,0x09,0x15,0x02,
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0xEE,0xA6,0xE0,0x5C,0xE0,0x77,0xC3,0x41,0x67,0x1B,0x3C,0x07,0x2A,0x06,0x19,0x07,
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0xE4,0x75,0xC6,0x43,0xCC,0x50,0x95,0x23,0x35,0x09,0x14,0x04,0x15,0x05,0x0B,0x04,
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0xEE,0xD6,0xED,0xAD,0xEC,0xB1,0xEB,0x79,0xAC,0x22,0x56,0x14,0x5A,0x12,0x26,0x0A,
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0xEE,0xBB,0xE7,0x7E,0xE9,0x8D,0xCB,0x49,0x67,0x11,0x34,0x07,0x2B,0x0B,0x14,0x07,
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0xED,0xA7,0xE5,0x76,0xE3,0x7E,0xC4,0x4B,0x77,0x14,0x34,0x08,0x27,0x07,0x14,0x04,
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0xE7,0x8B,0xD2,0x4C,0xCA,0x56,0x9E,0x31,0x36,0x0C,0x11,0x07,0x14,0x04,0x0A,0x02,
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0xF0,0x9B,0xEA,0x6F,0xE5,0x81,0xC4,0x43,0x74,0x10,0x30,0x0B,0x2D,0x08,0x1B,0x06,
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0xE6,0x83,0xCA,0x48,0xD9,0x56,0xA7,0x23,0x3B,0x09,0x12,0x09,0x15,0x07,0x0A,0x03,
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0xE5,0x5F,0xCB,0x3C,0xCF,0x48,0x91,0x22,0x31,0x0A,0x17,0x08,0x15,0x04,0x0D,0x02,
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0xD1,0x43,0x91,0x20,0xA9,0x2D,0x54,0x12,0x17,0x07,0x09,0x02,0x0C,0x04,0x05,0x03,
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};
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#endif
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// Read/write handlers are divided into multiple functions to keep rarely-used
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// functionality separate so often-used functionality can be optimized better
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// by compiler.
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// If write isn't preceded by read, data has this added to it
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int const no_read_before_write = 0x2000;
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void Snes_Spc::cpu_write_smp_reg_( int data, rel_time_t time, int addr )
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{
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switch ( addr )
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{
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case r_t0target:
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case r_t1target:
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case r_t2target: {
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Timer* t = &m.timers [addr - r_t0target];
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int period = IF_0_THEN_256( data );
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if ( t->period != period )
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{
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t = run_timer( t, time );
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#if SPC_MORE_ACCURACY
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// Insane behavior when target is written just after counter is
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// clocked and counter matches new period and new period isn't 1, 2, 4, or 8
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if ( t->divider == (period & 0xFF) &&
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t->next_time == time + TIMER_MUL( t, 1 ) &&
|
|
((period - 1) | ~0x0F) & period )
|
|
{
|
|
//dprintf( "SPC pathological timer target write\n" );
|
|
|
|
// If the period is 3, 5, or 9, there's a probability this behavior won't occur,
|
|
// based on the previous period
|
|
int prob = 0xFF;
|
|
int old_period = t->period & 0xFF;
|
|
if ( period == 3 ) prob = glitch_probs [0] [old_period];
|
|
if ( period == 5 ) prob = glitch_probs [1] [old_period];
|
|
if ( period == 9 ) prob = glitch_probs [2] [old_period];
|
|
|
|
// The glitch suppresses incrementing of one of the counter bits, based on
|
|
// the lowest set bit in the new period
|
|
int b = 1;
|
|
while ( !(period & b) )
|
|
b <<= 1;
|
|
|
|
if ( (rand() >> 4 & 0xFF) <= prob )
|
|
t->divider = (t->divider - b) & 0xFF;
|
|
}
|
|
#endif
|
|
t->period = period;
|
|
}
|
|
break;
|
|
}
|
|
|
|
case r_t0out:
|
|
case r_t1out:
|
|
case r_t2out:
|
|
if ( !SPC_MORE_ACCURACY )
|
|
dprintf( "SPC wrote to counter %d\n", (int) addr - r_t0out );
|
|
|
|
if ( data < no_read_before_write / 2 )
|
|
run_timer( &m.timers [addr - r_t0out], time - 1 )->counter = 0;
|
|
break;
|
|
|
|
// Registers that act like RAM
|
|
case 0x8:
|
|
case 0x9:
|
|
REGS_IN [addr] = (uint8_t) data;
|
|
break;
|
|
|
|
case r_test:
|
|
if ( (uint8_t) data != 0x0A )
|
|
dprintf( "SPC wrote to test register\n" );
|
|
break;
|
|
|
|
case r_control:
|
|
// port clears
|
|
if ( data & 0x10 )
|
|
{
|
|
REGS_IN [r_cpuio0] = 0;
|
|
REGS_IN [r_cpuio1] = 0;
|
|
}
|
|
if ( data & 0x20 )
|
|
{
|
|
REGS_IN [r_cpuio2] = 0;
|
|
REGS_IN [r_cpuio3] = 0;
|
|
}
|
|
|
|
// timers
|
|
{
|
|
for ( int i = 0; i < timer_count; i++ )
|
|
{
|
|
Timer* t = &m.timers [i];
|
|
int enabled = data >> i & 1;
|
|
if ( t->enabled != enabled )
|
|
{
|
|
t = run_timer( t, time );
|
|
t->enabled = enabled;
|
|
if ( enabled )
|
|
{
|
|
t->divider = 0;
|
|
t->counter = 0;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
enable_rom( data & 0x80 );
|
|
break;
|
|
}
|
|
}
|
|
|
|
void Snes_Spc::cpu_write_smp_reg( int data, rel_time_t time, int addr )
|
|
{
|
|
if ( addr == r_dspdata ) // 99%
|
|
dsp_write( data, time );
|
|
else
|
|
cpu_write_smp_reg_( data, time, addr );
|
|
}
|
|
|
|
void Snes_Spc::cpu_write_high( int data, int i, rel_time_t time )
|
|
{
|
|
if ( i < rom_size )
|
|
{
|
|
m.hi_ram [i] = (uint8_t) data;
|
|
if ( m.rom_enabled )
|
|
RAM [i + rom_addr] = m.rom [i]; // restore overwritten ROM
|
|
}
|
|
else
|
|
{
|
|
assert( RAM [i + rom_addr] == (uint8_t) data );
|
|
RAM [i + rom_addr] = cpu_pad_fill; // restore overwritten padding
|
|
cpu_write( data, i + rom_addr - 0x10000, time );
|
|
}
|
|
}
|
|
|
|
int const bits_in_int = CHAR_BIT * sizeof (int);
|
|
|
|
void Snes_Spc::cpu_write( int data, int addr, rel_time_t time )
|
|
{
|
|
MEM_ACCESS( time, addr )
|
|
|
|
// RAM
|
|
RAM [addr] = (uint8_t) data;
|
|
int reg = addr - 0xF0;
|
|
if ( reg >= 0 ) // 64%
|
|
{
|
|
// $F0-$FF
|
|
if ( reg < reg_count ) // 87%
|
|
{
|
|
REGS [reg] = (uint8_t) data;
|
|
|
|
// Ports
|
|
#ifdef SPC_PORT_WRITE_HOOK
|
|
if ( (unsigned) (reg - r_cpuio0) < port_count )
|
|
SPC_PORT_WRITE_HOOK( m.spc_time + time, (reg - r_cpuio0),
|
|
(uint8_t) data, ®S [r_cpuio0] );
|
|
#endif
|
|
|
|
// Registers other than $F2 and $F4-$F7
|
|
//if ( reg != 2 && reg != 4 && reg != 5 && reg != 6 && reg != 7 )
|
|
// TODO: this is a bit on the fragile side
|
|
if ( ((~0x2F00 << (bits_in_int - 16)) << reg) < 0 ) // 36%
|
|
cpu_write_smp_reg( data, time, reg );
|
|
}
|
|
// High mem/address wrap-around
|
|
else
|
|
{
|
|
reg -= rom_addr - 0xF0;
|
|
if ( reg >= 0 ) // 1% in IPL ROM area or address wrapped around
|
|
cpu_write_high( data, reg, time );
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
//// CPU read
|
|
|
|
inline int Snes_Spc::cpu_read_smp_reg( int reg, rel_time_t time )
|
|
{
|
|
int result = REGS_IN [reg];
|
|
reg -= r_dspaddr;
|
|
// DSP addr and data
|
|
if ( (unsigned) reg <= 1 ) // 4% 0xF2 and 0xF3
|
|
{
|
|
result = REGS [r_dspaddr];
|
|
if ( (unsigned) reg == 1 )
|
|
result = dsp_read( time ); // 0xF3
|
|
}
|
|
reg -= r_cpuio0 - r_dspaddr;
|
|
if ( (unsigned) reg <= 3 )
|
|
{
|
|
if ( m.sfm_queue && m.sfm_queue < m.sfm_queue_end )
|
|
{
|
|
result = *m.sfm_queue++;
|
|
}
|
|
}
|
|
return result;
|
|
}
|
|
|
|
int Snes_Spc::cpu_read( int addr, rel_time_t time )
|
|
{
|
|
MEM_ACCESS( time, addr )
|
|
|
|
// RAM
|
|
int result = RAM [addr];
|
|
int reg = addr - 0xF0;
|
|
if ( reg >= 0 ) // 40%
|
|
{
|
|
reg -= 0x10;
|
|
if ( (unsigned) reg >= 0xFF00 ) // 21%
|
|
{
|
|
reg += 0x10 - r_t0out;
|
|
|
|
// Timers
|
|
if ( (unsigned) reg < timer_count ) // 90%
|
|
{
|
|
Timer* t = &m.timers [reg];
|
|
if ( time >= t->next_time )
|
|
t = run_timer_( t, time );
|
|
result = t->counter;
|
|
t->counter = 0;
|
|
}
|
|
// Other registers
|
|
else if ( reg < 0 ) // 10%
|
|
{
|
|
result = cpu_read_smp_reg( reg + r_t0out, time );
|
|
}
|
|
else // 1%
|
|
{
|
|
assert( reg + (r_t0out + 0xF0 - 0x10000) < 0x100 );
|
|
result = cpu_read( reg + (r_t0out + 0xF0 - 0x10000), time );
|
|
}
|
|
}
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
|
|
//// Run
|
|
|
|
// Prefix and suffix for CPU emulator function
|
|
#define SPC_CPU_RUN_FUNC \
|
|
BOOST::uint8_t* Snes_Spc::run_until_( time_t end_time )\
|
|
{\
|
|
rel_time_t rel_time = m.spc_time - end_time;\
|
|
assert( rel_time <= 0 );\
|
|
m.spc_time = end_time;\
|
|
m.dsp_time += rel_time;\
|
|
m.timers [0].next_time += rel_time;\
|
|
m.timers [1].next_time += rel_time;\
|
|
m.timers [2].next_time += rel_time;
|
|
|
|
#define SPC_CPU_RUN_FUNC_END \
|
|
m.spc_time += rel_time;\
|
|
m.dsp_time -= rel_time;\
|
|
m.timers [0].next_time -= rel_time;\
|
|
m.timers [1].next_time -= rel_time;\
|
|
m.timers [2].next_time -= rel_time;\
|
|
assert( m.spc_time <= end_time );\
|
|
return ®S [r_cpuio0];\
|
|
}
|
|
|
|
int const cpu_lag_max = 12 - 1; // DIV YA,X takes 12 clocks
|
|
|
|
void Snes_Spc::end_frame( time_t end_time )
|
|
{
|
|
// Catch CPU up to as close to end as possible. If final instruction
|
|
// would exceed end, does NOT execute it and leaves m.spc_time < end.
|
|
if ( end_time > m.spc_time )
|
|
run_until_( end_time );
|
|
|
|
m.spc_time -= end_time;
|
|
m.extra_clocks += end_time;
|
|
|
|
// Greatest number of clocks early that emulation can stop early due to
|
|
// not being able to execute current instruction without going over
|
|
// allowed time.
|
|
assert( -cpu_lag_max <= m.spc_time && m.spc_time <= 0 );
|
|
|
|
// Catch timers up to CPU
|
|
for ( int i = 0; i < timer_count; i++ )
|
|
run_timer( &m.timers [i], 0 );
|
|
|
|
// Catch DSP up to CPU
|
|
if ( m.dsp_time < 0 )
|
|
{
|
|
RUN_DSP( 0, max_reg_time );
|
|
}
|
|
|
|
// Save any extra samples beyond what should be generated
|
|
if ( m.buf_begin )
|
|
save_extra();
|
|
}
|
|
|
|
// Inclusion here allows static memory access functions and better optimization
|
|
#include "Spc_Cpu.h"
|