/*************************************************************************************** * Genesis Plus * Mega CD / Sega CD hardware * * Copyright (C) 2012-2019 Eke-Eke (Genesis Plus GX) * * Redistribution and use of this code or any derivative works are permitted * provided that the following conditions are met: * * - Redistributions may not be sold, nor may they be used in a commercial * product or activity. * * - Redistributions that are modified from the original source must include the * complete source code, including the source code for all components used by a * binary built from the modified sources. However, as a special exception, the * source code distributed need not include anything that is normally distributed * (in either source or binary form) with the major components (compiler, kernel, * and so on) of the operating system on which the executable runs, unless that * component itself accompanies the executable. * * - Redistributions must reproduce the above copyright notice, this list of * conditions and the following disclaimer in the documentation and/or other * materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************************/ #ifndef _HW_SCD_ #define _HW_SCD_ #include "cdd.h" #include "cdc.h" #include "gfx.h" #include "pcm.h" #include "cd_cart.h" #ifdef USE_DYNAMIC_ALLOC #define scd ext->cd_hw #else #define scd ext.cd_hw #endif /* CD hardware Master Clock (50 MHz) */ #define SCD_CLOCK 50000000 /* ~3184 SCD clocks/line on NTSC system (53.693175 MHz Master Clock) */ /* ~3214 SCD clocks/line on PAL system (53.203424 MHz Master Clock) */ #define SCYCLES_PER_LINE scd.cycles_per_line /* Timer & Stopwatch clocks divider */ #define TIMERS_SCYCLES_RATIO (384 * 4) /* CD hardware */ typedef struct { cd_cart_t cartridge; /* ROM/RAM Cartridge */ uint8 bootrom[0x20000]; /* 128K internal BOOT ROM */ uint8 prg_ram[0x80000]; /* 512K PRG-RAM */ uint8 word_ram[2][0x20000]; /* 2 x 128K Word RAM (1M mode) */ uint8 word_ram_2M[0x40000]; /* 256K Word RAM (2M mode) */ uint8 bram[0x2000]; /* 8K Backup RAM */ reg16_t regs[0x100]; /* 256 x 16-bit ASIC registers */ uint32 cycles; /* CD Master clock counter */ uint32 cycles_per_line; /* CD Master clock count per scanline */ int32 stopwatch; /* Stopwatch counter */ int32 timer; /* Timer counter */ uint8 pending; /* Pending interrupts */ uint8 dmna; /* Pending DMNA write status */ gfx_t gfx_hw; /* Graphics processor */ cdc_t cdc_hw; /* CD data controller */ cdd_t cdd_hw; /* CD drive processor */ pcm_t pcm_hw; /* PCM chip */ } cd_hw_t; /* Function prototypes */ extern void scd_init(void); extern void scd_reset(int hard); extern void scd_update(unsigned int cycles); extern void scd_end_frame(unsigned int cycles); extern int scd_context_load(uint8 *state); extern int scd_context_save(uint8 *state); extern int scd_68k_irq_ack(int level); extern void prg_ram_dma_w(unsigned int words); #endif