mirror of
https://github.com/ekeeke/Genesis-Plus-GX.git
synced 2024-12-26 11:11:48 +01:00
96 lines
3.9 KiB
C
96 lines
3.9 KiB
C
/***************************************************************************************
|
|
* Genesis Plus
|
|
* Mega CD / Sega CD hardware
|
|
*
|
|
* Copyright (C) 2012-2016 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
|