Genesis-Plus-GX/core/cd_hw/cdc.h

79 lines
3.1 KiB
C

/***************************************************************************************
* Genesis Plus
* CD data controller (LC8951x compatible)
*
* Copyright (C) 2012-2024 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_CDC_
#define _HW_CDC_
#define cdc scd.cdc_hw
#define CDC_MAIN_CPU_ACCESS 0x42
#define CDC_SUB_CPU_ACCESS 0x43
/* CDC hardware */
typedef struct
{
uint8 ifstat;
uint8 ifctrl;
reg16_t dbc;
reg16_t dac;
reg16_t pt;
reg16_t wa;
uint8 ctrl[2];
uint8 head[2][4];
uint8 stat[4];
int cycles[2];
void (*dma_w)(unsigned int length); /* active DMA callback */
void (*halted_dma_w)(unsigned int length); /* halted DMA callback */
uint8 ram[0x4000 + 2352]; /* 16K external RAM (with one block overhead to handle buffer overrun) */
uint8 ar_mask;
uint8 irq; /* invert of CDC /INT output */
} cdc_t;
/* Function prototypes */
extern void cdc_init(void);
extern void cdc_reset(void);
extern int cdc_context_save(uint8 *state);
extern int cdc_context_load(uint8 *state);
extern void cdc_dma_init(void);
extern void cdc_dma_update(unsigned int cycles);
extern void cdc_decoder_update(uint32 header);
extern void cdc_reg_w(unsigned char data);
extern unsigned char cdc_reg_r(void);
extern unsigned short cdc_host_r(uint8 cpu_access);
#endif